Merge pull request #495 from schungx/master

Sync to 1.3.0

.github/workflows/build.yml

@@ -4,7 +4,7 @@ on:
   push:
     branches:
       - master
-      - v1.1-fixes
+      - v1.2-fixes
   pull_request: {}
 
 jobs:

CHANGELOG.md

@@ -1,6 +1,64 @@
 Rhai Release Notes
 ==================
 
+Version 1.3.0
+=============
+
+Compiler requirement
+--------------------
+
+* Minimum compiler version is bumped to 1.51.
+
+Bug fixes
+---------
+
+* BLOB's no longer panic when accessed with an out-of-bounds index.
+
+New features
+------------
+
+* New options for `Engine` which allows disabling `if`-expressions, `switch`-expressions, statement expressions, anonymous functions and/or looping (i.e. `while`, `loop`, `do` and `for` statements):
+  * `Engine::set_allow_if_expression`
+  * `Engine::set_allow_switch_expression`
+  * `Engine::set_allow_statement_expression`
+  * `Engine::set_allow_anonymous_fn`
+  * `Engine::set_allow_looping`
+* New _strict variables_ mode for `Engine` (enabled via `Engine::set_strict_variables`) to throw parse errors on undefined variable usage. Two new parse error variants, `ParseErrorType::VariableNotFound` and `ParseErrorType::ModuleNotFound`, are added.
+
+Enhancements
+------------
+
+* Added `into_array` and `into_typed_array` for `Dynamic`.
+* Added `FnPtr::call` and `FnPtr::call_within_context` to simplify calling a function pointer.
+* BLob's can now be deserialized (using `from_dynamic`) into `Vec<u8>` via [`serde_bytes`](https://crates.io/crates/serde_bytes).
+
+Deprecated and Gated API's
+--------------------------
+
+* `NativeCallContext::new` is deprecated because it is simpler to call a function pointer via `FnPtr::call`.
+* `AST::merge_filtered` and `AST::combine_filtered` are no longer exported under `no_function`.
+* `AST::new` and `AST::new_with_source` are moved under `internals`.
+* `FnPtr::call_dynamic` is deprecated in favor of `FnPtr::call_raw`.
+
+
+Version 1.2.2
+=============
+
+Bug fixes
+---------
+
+* `from_dynamic` now supports deserializing `Option`.
+
+
+Version 1.2.1
+=============
+
+Bug fixes
+---------
+
+* Array methods (such as `map`) taking a closure with captures as argument now works properly.
+
+
 Version 1.2.0
 =============
 
@@ -9,6 +67,9 @@ Bug fixes with breaking script changes
 
 * As originally intended, function calls with a bang (`!`) now operates directly on the caller's scope, allowing variables inside the scope to be mutated.
 * As originally intended, `Engine::XXX_with_scope` API's now properly propagate constants within the provided scope also to _functions_ in the script.
+* Printing of integral floating-point numbers is fixed (used to only prints `0.0`).
+* `func!()` calls now work properly under `no_closure`.
+* Fixed parsing of unary negation such that expressions like `if foo { ... } -x` parses correctly.
 
 New features
 ------------
@@ -37,17 +98,6 @@ Deprecated API's
 * `From<EvalAltResult>` for `Result<T, Box<EvalAltResult>>` is deprecated so it will no longer be possible to do `EvalAltResult::ErrorXXXXX.into()` to convert to a `Result`; instead, `Err(EvalAltResult:ErrorXXXXX.into())` must be used. Code is clearer if errors are explicitly wrapped in `Err`.
 
 
-Version 1.1.3
-=============
-
-Bug fixes
----------
-
-* Printing of integral floating-point numbers is fixed (used to only prints `0.0`).
-* `func!()` calls now work properly under `no_closure`.
-* Fixed parsing of unary negation such that expressions like `if foo { ... } -x` parses correctly.
-
-
 Version 1.1.2
 =============
 

Cargo.toml

@@ -3,7 +3,7 @@ members = [".", "codegen"]
 
 [package]
 name = "rhai"
-version = "1.2.0"
+version = "1.3.0"
 edition = "2018"
 authors = ["Jonathan Turner", "Lukáš Hozda", "Stephen Chung", "jhwgh1968"]
 description = "Embedded scripting for Rust"
@@ -16,12 +16,15 @@ keywords = ["scripting", "scripting-engine", "scripting-language", "embedded"]
 categories = ["no-std", "embedded", "wasm", "parser-implementations"]
 
 [dependencies]
-smallvec = { version = "1.6", default-features = false, features = ["union"] }
+smallvec = { version = "1.7", default-features = false, features = ["union", "const_new" ] }
 ahash = { version = "0.7", default-features = false }
 num-traits = { version = "0.2", default-features = false }
-smartstring = { version = "0.2.7", default-features = false }
+smartstring = { version = "0.2.8", default-features = false }
 rhai_codegen = { version = "1.2", path = "codegen", default-features = false }
 
+[dev-dependencies]
+serde_bytes = "0.11"
+
 [features]
 default = ["ahash/std", "num-traits/std"]
 unchecked = []                  # unchecked arithmetic
@@ -48,9 +51,6 @@ no_std = ["no-std-compat", "num-traits/libm", "core-error", "libm", "ahash/compi
 wasm-bindgen = ["instant/wasm-bindgen"]
 stdweb = ["instant/stdweb"]
 
-# internal feature flags - volatile
-no_smartstring = []             # do not use SmartString
-
 [profile.release]
 lto = "fat"
 codegen-units = 1

README.md

@@ -26,7 +26,7 @@ Targets and builds
 * All CPU and O/S targets supported by Rust, including:
   * WebAssembly (WASM)
   * `no-std`
-* Minimum Rust version 1.49
+* Minimum Rust version 1.51
 
 
 Standard features

benches/iterations.rs

@@ -45,3 +45,34 @@ fn bench_iterations_fibonacci(bench: &mut Bencher) {
 
     bench.iter(|| engine.eval_ast::<INT>(&ast).unwrap());
 }
+
+#[bench]
+fn bench_iterations_array(bench: &mut Bencher) {
+    let script = r#"
+            let x = [];
+            x.pad(1000, 0);
+            for i in range(0, 1000) { x[i] = i % 256; }
+        "#;
+
+    let mut engine = Engine::new();
+    engine.set_optimization_level(OptimizationLevel::None);
+
+    let ast = engine.compile(script).unwrap();
+
+    bench.iter(|| engine.run_ast(&ast).unwrap());
+}
+
+#[bench]
+fn bench_iterations_blob(bench: &mut Bencher) {
+    let script = r#"
+            let x = blob(1000, 0);
+            for i in range(0, 1000) { x[i] = i % 256; }
+        "#;
+
+    let mut engine = Engine::new();
+    engine.set_optimization_level(OptimizationLevel::None);
+
+    let ast = engine.compile(script).unwrap();
+
+    bench.iter(|| engine.run_ast(&ast).unwrap());
+}

codegen/ui_tests/non_clonable.stderr

@@ -1,5 +1,11 @@
 error[E0277]: the trait bound `NonClonable: Clone` is not satisfied
-  --> ui_tests/non_clonable.rs:11:23
+    --> ui_tests/non_clonable.rs:11:23
-   |
+     |
-11 | pub fn test_fn(input: NonClonable) -> bool {
+11   | pub fn test_fn(input: NonClonable) -> bool {
-   |                       ^^^^^^^^^^^ the trait `Clone` is not implemented for `NonClonable`
+     |                       ^^^^^^^^^^^ the trait `Clone` is not implemented for `NonClonable`
+     |
+note: required by a bound in `rhai::Dynamic::cast`
+    --> $WORKSPACE/src/types/dynamic.rs
+     |
+     |     pub fn cast<T: Any + Clone>(self) -> T {
+     |                          ^^^^^ required by this bound in `rhai::Dynamic::cast`

codegen/ui_tests/non_clonable_second.stderr

@@ -1,5 +1,11 @@
 error[E0277]: the trait bound `NonClonable: Clone` is not satisfied
-  --> ui_tests/non_clonable_second.rs:11:27
+    --> ui_tests/non_clonable_second.rs:11:27
-   |
+     |
-11 | pub fn test_fn(a: u32, b: NonClonable) -> bool {
+11   | pub fn test_fn(a: u32, b: NonClonable) -> bool {
-   |                           ^^^^^^^^^^^ the trait `Clone` is not implemented for `NonClonable`
+     |                           ^^^^^^^^^^^ the trait `Clone` is not implemented for `NonClonable`
+     |
+note: required by a bound in `rhai::Dynamic::cast`
+    --> $WORKSPACE/src/types/dynamic.rs
+     |
+     |     pub fn cast<T: Any + Clone>(self) -> T {
+     |                          ^^^^^ required by this bound in `rhai::Dynamic::cast`

src/api/call_fn.rs

@@ -0,0 +1,199 @@
+//! Module that defines the `call_fn` API of [`Engine`].
+#![cfg(not(feature = "no_function"))]
+
+use crate::engine::{EvalState, Imports};
+use crate::types::dynamic::Variant;
+use crate::{
+    Dynamic, Engine, EvalAltResult, FuncArgs, Position, RhaiResult, Scope, StaticVec, AST,
+};
+use std::any::type_name;
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Call a script function defined in an [`AST`] with multiple arguments.
+    ///
+    /// Not available under `no_function`.
+    ///
+    /// The [`AST`] is evaluated before calling the function.
+    /// This allows a script to load the necessary modules.
+    /// This is usually desired. If not, a specialized [`AST`] can be prepared that contains only
+    /// function definitions without any body script via [`AST::clear_statements`].
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_function"))]
+    /// # {
+    /// use rhai::{Engine, Scope};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// let ast = engine.compile("
+    ///     fn add(x, y) { len(x) + y + foo }
+    ///     fn add1(x)   { len(x) + 1 + foo }
+    ///     fn bar()     { foo/2 }
+    /// ")?;
+    ///
+    /// let mut scope = Scope::new();
+    /// scope.push("foo", 42_i64);
+    ///
+    /// // Call the script-defined function
+    /// let result: i64 = engine.call_fn(&mut scope, &ast, "add", ( "abc", 123_i64 ) )?;
+    /// assert_eq!(result, 168);
+    ///
+    /// let result: i64 = engine.call_fn(&mut scope, &ast, "add1", ( "abc", ) )?;
+    /// //                                                         ^^^^^^^^^^ tuple of one
+    /// assert_eq!(result, 46);
+    ///
+    /// let result: i64 = engine.call_fn(&mut scope, &ast, "bar", () )?;
+    /// assert_eq!(result, 21);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn call_fn<T: Variant + Clone>(
+        &self,
+        scope: &mut Scope,
+        ast: &AST,
+        name: impl AsRef<str>,
+        args: impl FuncArgs,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let mut arg_values = StaticVec::new_const();
+        args.parse(&mut arg_values);
+
+        let result = self.call_fn_raw(scope, ast, true, true, name, None, arg_values)?;
+
+        let typ = self.map_type_name(result.type_name());
+
+        result.try_cast().ok_or_else(|| {
+            EvalAltResult::ErrorMismatchOutputType(
+                self.map_type_name(type_name::<T>()).into(),
+                typ.into(),
+                Position::NONE,
+            )
+            .into()
+        })
+    }
+    /// Call a script function defined in an [`AST`] with multiple [`Dynamic`] arguments
+    /// and the following options:
+    ///
+    /// * whether to evaluate the [`AST`] to load necessary modules before calling the function
+    /// * whether to rewind the [`Scope`] after the function call
+    /// * a value for binding to the `this` pointer (if any)
+    ///
+    /// Not available under `no_function`.
+    ///
+    /// # WARNING - Low Level API
+    ///
+    /// This function is very low level.
+    ///
+    /// ## Arguments
+    ///
+    /// All the arguments are _consumed_, meaning that they're replaced by `()`.
+    /// This is to avoid unnecessarily cloning the arguments.
+    /// Do not use the arguments after this call. If they are needed afterwards,
+    /// clone them _before_ calling this function.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_function"))]
+    /// # {
+    /// use rhai::{Engine, Scope, Dynamic};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// let ast = engine.compile("
+    ///     fn add(x, y) { len(x) + y + foo }
+    ///     fn add1(x)   { len(x) + 1 + foo }
+    ///     fn bar()     { foo/2 }
+    ///     fn action(x) { this += x; }         // function using 'this' pointer
+    ///     fn decl(x)   { let hello = x; }     // declaring variables
+    /// ")?;
+    ///
+    /// let mut scope = Scope::new();
+    /// scope.push("foo", 42_i64);
+    ///
+    /// // Call the script-defined function
+    /// let result = engine.call_fn_raw(&mut scope, &ast, true, true, "add", None, [ "abc".into(), 123_i64.into() ])?;
+    /// //                                                                   ^^^^ no 'this' pointer
+    /// assert_eq!(result.cast::<i64>(), 168);
+    ///
+    /// let result = engine.call_fn_raw(&mut scope, &ast, true, true, "add1", None, [ "abc".into() ])?;
+    /// assert_eq!(result.cast::<i64>(), 46);
+    ///
+    /// let result = engine.call_fn_raw(&mut scope, &ast, true, true, "bar", None, [])?;
+    /// assert_eq!(result.cast::<i64>(), 21);
+    ///
+    /// let mut value: Dynamic = 1_i64.into();
+    /// let result = engine.call_fn_raw(&mut scope, &ast, true, true, "action", Some(&mut value), [ 41_i64.into() ])?;
+    /// //                                                                      ^^^^^^^^^^^^^^^^ binding the 'this' pointer
+    /// assert_eq!(value.as_int().expect("value should be INT"), 42);
+    ///
+    /// engine.call_fn_raw(&mut scope, &ast, true, false, "decl", None, [ 42_i64.into() ])?;
+    /// //                                         ^^^^^ do not rewind scope
+    /// assert_eq!(scope.get_value::<i64>("hello").unwrap(), 42);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn call_fn_raw(
+        &self,
+        scope: &mut Scope,
+        ast: &AST,
+        eval_ast: bool,
+        rewind_scope: bool,
+        name: impl AsRef<str>,
+        this_ptr: Option<&mut Dynamic>,
+        arg_values: impl AsMut<[Dynamic]>,
+    ) -> RhaiResult {
+        let state = &mut EvalState::new();
+        let mods = &mut Imports::new();
+        let statements = ast.statements();
+
+        let orig_scope_len = scope.len();
+
+        if eval_ast && !statements.is_empty() {
+            // Make sure new variables introduced at global level do not _spill_ into the function call
+            self.eval_global_statements(scope, mods, state, statements, &[ast.as_ref()], 0)?;
+
+            if rewind_scope {
+                scope.rewind(orig_scope_len);
+            }
+        }
+
+        let name = name.as_ref();
+        let mut this_ptr = this_ptr;
+        let mut arg_values = arg_values;
+        let mut args: StaticVec<_> = arg_values.as_mut().iter_mut().collect();
+
+        let fn_def = ast
+            .shared_lib()
+            .get_script_fn(name, args.len())
+            .ok_or_else(|| EvalAltResult::ErrorFunctionNotFound(name.into(), Position::NONE))?;
+
+        // Check for data race.
+        #[cfg(not(feature = "no_closure"))]
+        crate::func::call::ensure_no_data_race(name, &mut args, false)?;
+
+        let result = self.call_script_fn(
+            scope,
+            mods,
+            state,
+            &[ast.as_ref()],
+            &mut this_ptr,
+            fn_def,
+            &mut args,
+            Position::NONE,
+            rewind_scope,
+            0,
+        );
+
+        result
+    }
+}

src/api/compile.rs

@@ -0,0 +1,420 @@
+//! Module that defines the public compilation API of [`Engine`].
+
+use crate::parser::ParseState;
+use crate::{Engine, ParseError, Scope, AST};
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+#[cfg(not(feature = "no_object"))]
+use crate::Map;
+
+impl Engine {
+    /// Compile a string into an [`AST`], which can be used later for evaluation.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Compile a script to an AST and store it for later evaluation
+    /// let ast = engine.compile("40 + 2")?;
+    ///
+    /// for _ in 0..42 {
+    ///     assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn compile(&self, script: impl AsRef<str>) -> Result<AST, ParseError> {
+        self.compile_with_scope(&Scope::new(), script)
+    }
+    /// Compile a string into an [`AST`] using own scope, which can be used later for evaluation.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_optimize"))]
+    /// # {
+    /// use rhai::{Engine, Scope, OptimizationLevel};
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push_constant("x", 42_i64);   // 'x' is a constant
+    ///
+    /// // Compile a script to an AST and store it for later evaluation.
+    /// // Notice that `Full` optimization is on, so constants are folded
+    /// // into function calls and operators.
+    /// let ast = engine.compile_with_scope(&mut scope,
+    ///             "if x > 40 { x } else { 0 }"    // all 'x' are replaced with 42
+    /// )?;
+    ///
+    /// // Normally this would have failed because no scope is passed into the 'eval_ast'
+    /// // call and so the variable 'x' does not exist.  Here, it passes because the script
+    /// // has been optimized and all references to 'x' are already gone.
+    /// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn compile_with_scope(
+        &self,
+        scope: &Scope,
+        script: impl AsRef<str>,
+    ) -> Result<AST, ParseError> {
+        self.compile_scripts_with_scope(scope, &[script])
+    }
+    /// Compile a string into an [`AST`] using own scope, which can be used later for evaluation,
+    /// embedding all imported modules.
+    ///
+    /// Not available under `no_module`.
+    ///
+    /// Modules referred by `import` statements containing literal string paths are eagerly resolved
+    /// via the current [module resolver][crate::ModuleResolver] and embedded into the resultant
+    /// [`AST`]. When it is evaluated later, `import` statement directly recall pre-resolved
+    /// [modules][crate::Module] and the resolution process is not performed again.
+    #[cfg(not(feature = "no_module"))]
+    pub fn compile_into_self_contained(
+        &self,
+        scope: &Scope,
+        script: impl AsRef<str>,
+    ) -> Result<AST, Box<crate::EvalAltResult>> {
+        use crate::{
+            ast::{ASTNode, Expr, Stmt},
+            func::native::shared_take_or_clone,
+            module::resolvers::StaticModuleResolver,
+        };
+        use std::collections::BTreeSet;
+
+        fn collect_imports(
+            ast: &AST,
+            resolver: &StaticModuleResolver,
+            imports: &mut BTreeSet<crate::Identifier>,
+        ) {
+            ast.walk(
+                &mut |path| match path.last().expect("contains current node") {
+                    // Collect all `import` statements with a string constant path
+                    ASTNode::Stmt(Stmt::Import(Expr::StringConstant(s, _), _, _))
+                        if !resolver.contains_path(s) && !imports.contains(s.as_str()) =>
+                    {
+                        imports.insert(s.clone().into());
+                        true
+                    }
+                    _ => true,
+                },
+            );
+        }
+
+        let mut ast = self.compile_scripts_with_scope(scope, &[script])?;
+
+        if let Some(ref module_resolver) = self.module_resolver {
+            let mut resolver = StaticModuleResolver::new();
+            let mut imports = BTreeSet::new();
+
+            collect_imports(&ast, &resolver, &mut imports);
+
+            if !imports.is_empty() {
+                while let Some(path) = imports.iter().next() {
+                    let path = path.clone();
+
+                    match module_resolver.resolve_ast(self, None, &path, crate::Position::NONE) {
+                        Some(Ok(module_ast)) => {
+                            collect_imports(&module_ast, &resolver, &mut imports)
+                        }
+                        Some(err) => return err,
+                        None => (),
+                    }
+
+                    let module =
+                        module_resolver.resolve(self, None, &path, crate::Position::NONE)?;
+                    let module = shared_take_or_clone(module);
+
+                    imports.remove(&path);
+                    resolver.insert(path, module);
+                }
+                ast.set_resolver(resolver);
+            }
+        }
+
+        Ok(ast)
+    }
+    /// When passed a list of strings, first join the strings into one large script, and then
+    /// compile them into an [`AST`] using own scope, which can be used later for evaluation.
+    ///
+    /// The scope is useful for passing constants into the script for optimization when using
+    /// [`OptimizationLevel::Full`][crate::OptimizationLevel::Full].
+    ///
+    /// ## Note
+    ///
+    /// All strings are simply parsed one after another with nothing inserted in between, not even a
+    /// newline or space.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_optimize"))]
+    /// # {
+    /// use rhai::{Engine, Scope, OptimizationLevel};
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push_constant("x", 42_i64);   // 'x' is a constant
+    ///
+    /// // Compile a script made up of script segments to an AST and store it for later evaluation.
+    /// // Notice that `Full` optimization is on, so constants are folded
+    /// // into function calls and operators.
+    /// let ast = engine.compile_scripts_with_scope(&mut scope, &[
+    ///             "if x > 40",            // all 'x' are replaced with 42
+    ///             "{ x } el",
+    ///             "se { 0 }"              // segments do not need to be valid scripts!
+    /// ])?;
+    ///
+    /// // Normally this would have failed because no scope is passed into the 'eval_ast'
+    /// // call and so the variable 'x' does not exist.  Here, it passes because the script
+    /// // has been optimized and all references to 'x' are already gone.
+    /// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn compile_scripts_with_scope(
+        &self,
+        scope: &Scope,
+        scripts: &[impl AsRef<str>],
+    ) -> Result<AST, ParseError> {
+        self.compile_with_scope_and_optimization_level(
+            scope,
+            scripts,
+            #[cfg(not(feature = "no_optimize"))]
+            self.optimization_level,
+        )
+    }
+    /// Join a list of strings and compile into an [`AST`] using own scope at a specific optimization level.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`], constants defined within the scope are propagated
+    /// throughout the script _including_ functions. This allows functions to be optimized based on
+    /// dynamic global constants.
+    #[inline]
+    pub(crate) fn compile_with_scope_and_optimization_level(
+        &self,
+        scope: &Scope,
+        scripts: &[impl AsRef<str>],
+        #[cfg(not(feature = "no_optimize"))] optimization_level: crate::OptimizationLevel,
+    ) -> Result<AST, ParseError> {
+        let (stream, tokenizer_control) =
+            self.lex_raw(scripts, self.token_mapper.as_ref().map(Box::as_ref));
+        let mut state = ParseState::new(self, tokenizer_control);
+        self.parse(
+            &mut stream.peekable(),
+            &mut state,
+            scope,
+            #[cfg(not(feature = "no_optimize"))]
+            optimization_level,
+        )
+    }
+    /// Compile a string containing an expression into an [`AST`],
+    /// which can be used later for evaluation.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Compile a script to an AST and store it for later evaluation
+    /// let ast = engine.compile_expression("40 + 2")?;
+    ///
+    /// for _ in 0..42 {
+    ///     assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn compile_expression(&self, script: impl AsRef<str>) -> Result<AST, ParseError> {
+        self.compile_expression_with_scope(&Scope::new(), script)
+    }
+    /// Compile a string containing an expression into an [`AST`] using own scope,
+    /// which can be used later for evaluation.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_optimize"))]
+    /// # {
+    /// use rhai::{Engine, Scope, OptimizationLevel};
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push_constant("x", 10_i64);   // 'x' is a constant
+    ///
+    /// // Compile a script to an AST and store it for later evaluation.
+    /// // Notice that `Full` optimization is on, so constants are folded
+    /// // into function calls and operators.
+    /// let ast = engine.compile_expression_with_scope(&mut scope,
+    ///             "2 + (x + x) * 2"    // all 'x' are replaced with 10
+    /// )?;
+    ///
+    /// // Normally this would have failed because no scope is passed into the 'eval_ast'
+    /// // call and so the variable 'x' does not exist.  Here, it passes because the script
+    /// // has been optimized and all references to 'x' are already gone.
+    /// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn compile_expression_with_scope(
+        &self,
+        scope: &Scope,
+        script: impl AsRef<str>,
+    ) -> Result<AST, ParseError> {
+        let scripts = [script];
+        let (stream, tokenizer_control) =
+            self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
+
+        let mut peekable = stream.peekable();
+        let mut state = ParseState::new(self, tokenizer_control);
+        self.parse_global_expr(
+            &mut peekable,
+            &mut state,
+            scope,
+            #[cfg(not(feature = "no_optimize"))]
+            self.optimization_level,
+        )
+    }
+    /// Parse a JSON string into an [object map][`Map`].
+    /// This is a light-weight alternative to using, say,
+    /// [`serde_json`](https://crates.io/crates/serde_json) to deserialize the JSON.
+    ///
+    /// Not available under `no_object`.
+    ///
+    /// The JSON string must be an object hash.  It cannot be a simple scalar value.
+    ///
+    /// Set `has_null` to `true` in order to map `null` values to `()`.
+    /// Setting it to `false` will cause an [`ErrorVariableNotFound`][crate::EvalAltResult::ErrorVariableNotFound] error during parsing.
+    ///
+    /// # JSON With Sub-Objects
+    ///
+    /// This method assumes no sub-objects in the JSON string.  That is because the syntax
+    /// of a JSON sub-object (or object hash), `{ .. }`, is different from Rhai's syntax, `#{ .. }`.
+    /// Parsing a JSON string with sub-objects will cause a syntax error.
+    ///
+    /// If it is certain that the character `{` never appears in any text string within the JSON object,
+    /// which is a valid assumption for many use cases, then globally replace `{` with `#{` before calling this method.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Map};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// let map = engine.parse_json(
+    ///     r#"{"a":123, "b":42, "c":{"x":false, "y":true}, "d":null}"#
+    ///         .replace("{", "#{").as_str(),
+    /// true)?;
+    ///
+    /// assert_eq!(map.len(), 4);
+    /// assert_eq!(map["a"].as_int().expect("a should exist"), 123);
+    /// assert_eq!(map["b"].as_int().expect("b should exist"), 42);
+    /// assert!(map["d"].is::<()>());
+    ///
+    /// let c = map["c"].read_lock::<Map>().expect("c should exist");
+    /// assert_eq!(c["x"].as_bool().expect("x should be bool"), false);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[cfg(not(feature = "no_object"))]
+    #[inline(always)]
+    pub fn parse_json(
+        &self,
+        json: impl AsRef<str>,
+        has_null: bool,
+    ) -> Result<Map, Box<crate::EvalAltResult>> {
+        use crate::tokenizer::Token;
+
+        fn parse_json_inner(
+            engine: &Engine,
+            json: &str,
+            has_null: bool,
+        ) -> Result<Map, Box<crate::EvalAltResult>> {
+            let mut scope = Scope::new();
+            let json_text = json.trim_start();
+            let scripts = if json_text.starts_with(Token::MapStart.literal_syntax()) {
+                [json_text, ""]
+            } else if json_text.starts_with(Token::LeftBrace.literal_syntax()) {
+                ["#", json_text]
+            } else {
+                return Err(crate::ParseErrorType::MissingToken(
+                    Token::LeftBrace.syntax().into(),
+                    "to start a JSON object hash".into(),
+                )
+                .into_err(crate::Position::new(
+                    1,
+                    (json.len() - json_text.len() + 1) as u16,
+                ))
+                .into());
+            };
+            let (stream, tokenizer_control) = engine.lex_raw(
+                &scripts,
+                if has_null {
+                    Some(&|token, _, _| {
+                        match token {
+                            // If `null` is present, make sure `null` is treated as a variable
+                            Token::Reserved(s) if &*s == "null" => Token::Identifier(s),
+                            _ => token,
+                        }
+                    })
+                } else {
+                    None
+                },
+            );
+            let mut state = ParseState::new(engine, tokenizer_control);
+            let ast = engine.parse_global_expr(
+                &mut stream.peekable(),
+                &mut state,
+                &scope,
+                #[cfg(not(feature = "no_optimize"))]
+                crate::OptimizationLevel::None,
+            )?;
+            if has_null {
+                scope.push_constant("null", ());
+            }
+            engine.eval_ast_with_scope(&mut scope, &ast)
+        }
+
+        parse_json_inner(self, json.as_ref(), has_null)
+    }
+}

src/api/deprecated.rs

@@ -1,7 +1,8 @@
 //! Module containing all deprecated API that will be removed in the next major version.
 
 use crate::{
-    Dynamic, Engine, EvalAltResult, ImmutableString, NativeCallContext, RhaiResult, Scope, AST,
+    Dynamic, Engine, EvalAltResult, FnPtr, ImmutableString, NativeCallContext, RhaiResult, Scope,
+    AST,
 };
 
 #[cfg(feature = "no_std")]
@@ -80,7 +81,7 @@ impl Engine {
         self.run_with_scope(scope, script)
     }
 
-    /// Evaluate an AST, but throw away the result and only return error (if any).
+    /// Evaluate an [`AST`], but throw away the result and only return error (if any).
     /// Useful for when you don't need the result, but still need to keep track of possible errors.
     ///
     /// # Deprecated
@@ -124,7 +125,11 @@ impl Engine {
     ///
     /// This method will be removed in the next major version.
     ///
-    /// # WARNING
+    /// # WARNING - Low Level API
+    ///
+    /// This function is very low level.
+    ///
+    /// ## Arguments
     ///
     /// All the arguments are _consumed_, meaning that they're replaced by `()`.
     /// This is to avoid unnecessarily cloning the arguments.
@@ -220,16 +225,26 @@ impl Dynamic {
 impl NativeCallContext<'_> {
     /// Call a function inside the call context.
     ///
-    /// # WARNING
+    /// # WARNING - Low Level API
     ///
-    /// All arguments may be _consumed_, meaning that they may be replaced by `()`.
+    /// This function is very low level.
-    /// This is to avoid unnecessarily cloning the arguments.
     ///
-    /// Do not use the arguments after this call. If they are needed afterwards,
+    /// ## Arguments
-    /// clone them _before_ calling this function.
     ///
-    /// If `is_method` is [`true`], the first argument is assumed to be passed
+    /// All arguments may be _consumed_, meaning that they may be replaced by `()`. This is to avoid
-    /// by reference and is not consumed.
+    /// unnecessarily cloning the arguments.
+    ///
+    /// Do not use the arguments after this call. If they are needed afterwards, clone them _before_
+    /// calling this function.
+    ///
+    /// If `is_method` is [`true`], the first argument is assumed to be passed by reference and is
+    /// not consumed.
+    ///
+    /// # Deprecated
+    ///
+    /// This method is deprecated. Use [`call_fn_raw`][NativeCallContext::call_fn_raw] instead.
+    ///
+    /// This method will be removed in the next major version.
     #[deprecated(since = "1.2.0", note = "use `call_fn_raw` instead")]
     #[inline(always)]
     pub fn call_fn_dynamic_raw(
@@ -250,3 +265,43 @@ impl<T> From<EvalAltResult> for Result<T, Box<EvalAltResult>> {
         Err(err.into())
     }
 }
+
+impl FnPtr {
+    /// Call the function pointer with curried arguments (if any).
+    /// The function may be script-defined (not available under `no_function`) or native Rust.
+    ///
+    /// This method is intended for calling a function pointer that is passed into a native Rust
+    /// function as an argument.  Therefore, the [`AST`] is _NOT_ evaluated before calling the
+    /// function.
+    ///
+    /// # Deprecated
+    ///
+    /// This method is deprecated. Use [`call_within_context`][FnPtr::call_within_context] or
+    /// [`call_raw`][FnPtr::call_raw] instead.
+    ///
+    /// This method will be removed in the next major version.
+    ///
+    /// # WARNING - Low Level API
+    ///
+    /// This function is very low level.
+    ///
+    /// ## Arguments
+    ///
+    /// All the arguments are _consumed_, meaning that they're replaced by `()`.
+    /// This is to avoid unnecessarily cloning the arguments.
+    /// Do not use the arguments after this call. If they are needed afterwards,
+    /// clone them _before_ calling this function.
+    #[deprecated(
+        since = "1.3.0",
+        note = "use `call_within_context` or `call_raw` instead"
+    )]
+    #[inline(always)]
+    pub fn call_dynamic(
+        &self,
+        context: &NativeCallContext,
+        this_ptr: Option<&mut Dynamic>,
+        arg_values: impl AsMut<[Dynamic]>,
+    ) -> RhaiResult {
+        self.call_raw(context, this_ptr, arg_values)
+    }
+}

src/api/eval.rs

@@ -0,0 +1,240 @@
+//! Module that defines the public evaluation API of [`Engine`].
+
+use crate::engine::{EvalState, Imports};
+use crate::parser::ParseState;
+use crate::types::dynamic::Variant;
+use crate::{Dynamic, Engine, EvalAltResult, Module, Position, RhaiResult, Scope, AST};
+use std::any::type_name;
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Evaluate a string.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// assert_eq!(engine.eval::<i64>("40 + 2")?, 42);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn eval<T: Variant + Clone>(&self, script: &str) -> Result<T, Box<EvalAltResult>> {
+        self.eval_with_scope(&mut Scope::new(), script)
+    }
+    /// Evaluate a string with own scope.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Scope};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push("x", 40_i64);
+    ///
+    /// assert_eq!(engine.eval_with_scope::<i64>(&mut scope, "x += 2; x")?, 42);
+    /// assert_eq!(engine.eval_with_scope::<i64>(&mut scope, "x += 2; x")?, 44);
+    ///
+    /// // The variable in the scope is modified
+    /// assert_eq!(scope.get_value::<i64>("x").expect("variable x should exist"), 44);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn eval_with_scope<T: Variant + Clone>(
+        &self,
+        scope: &mut Scope,
+        script: &str,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let ast = self.compile_with_scope_and_optimization_level(
+            scope,
+            &[script],
+            #[cfg(not(feature = "no_optimize"))]
+            self.optimization_level,
+        )?;
+        self.eval_ast_with_scope(scope, &ast)
+    }
+    /// Evaluate a string containing an expression.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// assert_eq!(engine.eval_expression::<i64>("40 + 2")?, 42);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn eval_expression<T: Variant + Clone>(
+        &self,
+        script: &str,
+    ) -> Result<T, Box<EvalAltResult>> {
+        self.eval_expression_with_scope(&mut Scope::new(), script)
+    }
+    /// Evaluate a string containing an expression with own scope.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Scope};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push("x", 40_i64);
+    ///
+    /// assert_eq!(engine.eval_expression_with_scope::<i64>(&mut scope, "x + 2")?, 42);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn eval_expression_with_scope<T: Variant + Clone>(
+        &self,
+        scope: &mut Scope,
+        script: &str,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let scripts = [script];
+        let (stream, tokenizer_control) =
+            self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
+        let mut state = ParseState::new(self, tokenizer_control);
+
+        // No need to optimize a lone expression
+        let ast = self.parse_global_expr(
+            &mut stream.peekable(),
+            &mut state,
+            scope,
+            #[cfg(not(feature = "no_optimize"))]
+            crate::OptimizationLevel::None,
+        )?;
+
+        self.eval_ast_with_scope(scope, &ast)
+    }
+    /// Evaluate an [`AST`].
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Compile a script to an AST and store it for later evaluation
+    /// let ast = engine.compile("40 + 2")?;
+    ///
+    /// // Evaluate it
+    /// assert_eq!(engine.eval_ast::<i64>(&ast)?, 42);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn eval_ast<T: Variant + Clone>(&self, ast: &AST) -> Result<T, Box<EvalAltResult>> {
+        self.eval_ast_with_scope(&mut Scope::new(), ast)
+    }
+    /// Evaluate an [`AST`] with own scope.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Scope};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Compile a script to an AST and store it for later evaluation
+    /// let ast = engine.compile("x + 2")?;
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push("x", 40_i64);
+    ///
+    /// // Compile a script to an AST and store it for later evaluation
+    /// let ast = engine.compile("x += 2; x")?;
+    ///
+    /// // Evaluate it
+    /// assert_eq!(engine.eval_ast_with_scope::<i64>(&mut scope, &ast)?, 42);
+    /// assert_eq!(engine.eval_ast_with_scope::<i64>(&mut scope, &ast)?, 44);
+    ///
+    /// // The variable in the scope is modified
+    /// assert_eq!(scope.get_value::<i64>("x").expect("variable x should exist"), 44);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn eval_ast_with_scope<T: Variant + Clone>(
+        &self,
+        scope: &mut Scope,
+        ast: &AST,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let mods = &mut Imports::new();
+
+        let result = self.eval_ast_with_scope_raw(scope, mods, ast, 0)?;
+
+        let typ = self.map_type_name(result.type_name());
+
+        result.try_cast::<T>().ok_or_else(|| {
+            EvalAltResult::ErrorMismatchOutputType(
+                self.map_type_name(type_name::<T>()).into(),
+                typ.into(),
+                Position::NONE,
+            )
+            .into()
+        })
+    }
+    /// Evaluate an [`AST`] with own scope.
+    #[inline]
+    pub(crate) fn eval_ast_with_scope_raw<'a>(
+        &self,
+        scope: &mut Scope,
+        mods: &mut Imports,
+        ast: &'a AST,
+        level: usize,
+    ) -> RhaiResult {
+        let mut state = EvalState::new();
+        if ast.source_raw().is_some() {
+            mods.source = ast.source_raw().cloned();
+        }
+        #[cfg(not(feature = "no_module"))]
+        {
+            mods.embedded_module_resolver = ast.resolver().cloned();
+        }
+
+        let statements = ast.statements();
+
+        if statements.is_empty() {
+            return Ok(Dynamic::UNIT);
+        }
+
+        let lib = [
+            #[cfg(not(feature = "no_function"))]
+            ast.as_ref(),
+        ];
+        let lib = if lib.first().map(|m: &&Module| m.is_empty()).unwrap_or(true) {
+            &lib[0..0]
+        } else {
+            &lib
+        };
+        self.eval_global_statements(scope, mods, &mut state, statements, lib, level)
+    }
+}

src/api/events.rs

@@ -0,0 +1,265 @@
+//! Module that defines public event handlers for [`Engine`].
+
+use crate::engine::EvalContext;
+use crate::func::SendSync;
+use crate::{Dynamic, Engine, EvalAltResult, Position};
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Provide a callback that will be invoked before each variable access.
+    ///
+    /// # Callback Function Signature
+    ///
+    /// The callback function signature takes the following form:
+    ///
+    /// > `Fn(name: &str, index: usize, context: &EvalContext)`  
+    /// > `   -> Result<Option<Dynamic>, Box<EvalAltResult>> + 'static`
+    ///
+    /// where:
+    /// * `index`: an offset from the bottom of the current [`Scope`][crate::Scope] that the
+    ///   variable is supposed to reside. Offsets start from 1, with 1 meaning the last variable in
+    ///   the current [`Scope`][crate::Scope].  Essentially the correct variable is at position
+    ///   `scope.len() - index`. If `index` is zero, then there is no pre-calculated offset position
+    ///   and a search through the current [`Scope`][crate::Scope] must be performed.
+    ///
+    /// * `context`: the current [evaluation context][`EvalContext`].
+    ///
+    /// ## Return value
+    ///
+    /// * `Ok(None)`: continue with normal variable access.
+    /// * `Ok(Some(Dynamic))`: the variable's value.
+    ///
+    /// ## Raising errors
+    ///
+    /// Return `Err(...)` if there is an error.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Register a variable resolver.
+    /// engine.on_var(|name, _, _| {
+    ///     match name {
+    ///         "MYSTIC_NUMBER" => Ok(Some(42_i64.into())),
+    ///         _ => Ok(None)
+    ///     }
+    /// });
+    ///
+    /// engine.eval::<i64>("MYSTIC_NUMBER")?;
+    ///
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn on_var(
+        &mut self,
+        callback: impl Fn(&str, usize, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>>
+            + SendSync
+            + 'static,
+    ) -> &mut Self {
+        self.resolve_var = Some(Box::new(callback));
+        self
+    }
+    /// _(internals)_ Provide a callback that will be invoked during parsing to remap certain tokens.
+    /// Exported under the `internals` feature only.
+    ///
+    /// # Callback Function Signature
+    ///
+    /// The callback function signature takes the following form:
+    ///
+    /// > `Fn(token: Token, pos: Position, state: &TokenizeState) -> Token`
+    ///
+    /// where:
+    /// * [`token`][crate::tokenizer::Token]: current token parsed
+    /// * [`pos`][`Position`]: location of the token
+    /// * [`state`][crate::tokenizer::TokenizeState]: current state of the tokenizer
+    ///
+    /// ## Raising errors
+    ///
+    /// It is possible to raise a parsing error by returning
+    /// [`Token::LexError`][crate::tokenizer::Token::LexError] as the mapped token.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Token};
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Register a token mapper.
+    /// engine.on_parse_token(|token, _, _| {
+    ///     match token {
+    ///         // Convert all integer literals to strings
+    ///         Token::IntegerConstant(n) => Token::StringConstant(n.to_string().into()),
+    ///         // Convert 'begin' .. 'end' to '{' .. '}'
+    ///         Token::Identifier(s) if &*s == "begin" => Token::LeftBrace,
+    ///         Token::Identifier(s) if &*s == "end" => Token::RightBrace,
+    ///         // Pass through all other tokens unchanged
+    ///         _ => token
+    ///     }
+    /// });
+    ///
+    /// assert_eq!(engine.eval::<String>("42")?, "42");
+    /// assert_eq!(engine.eval::<bool>("true")?, true);
+    /// assert_eq!(engine.eval::<String>("let x = 42; begin let x = 0; end; x")?, "42");
+    ///
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[cfg(feature = "internals")]
+    #[inline(always)]
+    pub fn on_parse_token(
+        &mut self,
+        callback: impl Fn(
+                crate::tokenizer::Token,
+                Position,
+                &crate::tokenizer::TokenizeState,
+            ) -> crate::tokenizer::Token
+            + SendSync
+            + 'static,
+    ) -> &mut Self {
+        self.token_mapper = Some(Box::new(callback));
+        self
+    }
+    /// Register a callback for script evaluation progress.
+    ///
+    /// Not available under `unchecked`.
+    ///
+    /// # Callback Function Signature
+    ///
+    /// The callback function signature takes the following form:
+    ///
+    /// > `Fn(counter: u64) -> Option<Dynamic>`
+    ///
+    /// ## Return value
+    ///
+    /// * `None`: continue running the script.
+    /// * `Some(Dynamic)`: terminate the script with the specified exception value.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # use std::sync::RwLock;
+    /// # use std::sync::Arc;
+    /// use rhai::Engine;
+    ///
+    /// let result = Arc::new(RwLock::new(0_u64));
+    /// let logger = result.clone();
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// engine.on_progress(move |ops| {
+    ///     if ops > 10000 {
+    ///         Some("Over 10,000 operations!".into())
+    ///     } else if ops % 800 == 0 {
+    ///         *logger.write().unwrap() = ops;
+    ///         None
+    ///     } else {
+    ///         None
+    ///     }
+    /// });
+    ///
+    /// engine.run("for x in range(0, 50000) {}")
+    ///       .expect_err("should error");
+    ///
+    /// assert_eq!(*result.read().unwrap(), 9600);
+    ///
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[cfg(not(feature = "unchecked"))]
+    #[inline(always)]
+    pub fn on_progress(
+        &mut self,
+        callback: impl Fn(u64) -> Option<Dynamic> + SendSync + 'static,
+    ) -> &mut Self {
+        self.progress = Some(Box::new(callback));
+        self
+    }
+    /// Override default action of `print` (print to stdout using [`println!`])
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # use std::sync::RwLock;
+    /// # use std::sync::Arc;
+    /// use rhai::Engine;
+    ///
+    /// let result = Arc::new(RwLock::new(String::new()));
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Override action of 'print' function
+    /// let logger = result.clone();
+    /// engine.on_print(move |s| logger.write().unwrap().push_str(s));
+    ///
+    /// engine.run("print(40 + 2);")?;
+    ///
+    /// assert_eq!(*result.read().unwrap(), "42");
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn on_print(&mut self, callback: impl Fn(&str) + SendSync + 'static) -> &mut Self {
+        self.print = Some(Box::new(callback));
+        self
+    }
+    /// Override default action of `debug` (print to stdout using [`println!`])
+    ///
+    /// # Callback Function Signature
+    ///
+    /// The callback function signature passed takes the following form:
+    ///
+    /// > `Fn(text: &str, source: Option<&str>, pos: Position)`
+    ///
+    /// where:
+    /// * `text`: the text to display
+    /// * `source`: current source, if any
+    /// * [`pos`][`Position`]: location of the `debug` call
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # use std::sync::RwLock;
+    /// # use std::sync::Arc;
+    /// use rhai::Engine;
+    ///
+    /// let result = Arc::new(RwLock::new(String::new()));
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Override action of 'print' function
+    /// let logger = result.clone();
+    /// engine.on_debug(move |s, src, pos| logger.write().unwrap().push_str(
+    ///                     &format!("{} @ {:?} > {}", src.unwrap_or("unknown"), pos, s)
+    ///                ));
+    ///
+    /// let mut ast = engine.compile(r#"let x = "hello"; debug(x);"#)?;
+    /// ast.set_source("world");
+    /// engine.run_ast(&ast)?;
+    ///
+    /// #[cfg(not(feature = "no_position"))]
+    /// assert_eq!(*result.read().unwrap(), r#"world @ 1:18 > "hello""#);
+    /// #[cfg(feature = "no_position")]
+    /// assert_eq!(*result.read().unwrap(), r#"world @ none > "hello""#);
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn on_debug(
+        &mut self,
+        callback: impl Fn(&str, Option<&str>, Position) + SendSync + 'static,
+    ) -> &mut Self {
+        self.debug = Some(Box::new(callback));
+        self
+    }
+}

src/api/files.rs

@@ -0,0 +1,196 @@
+//! Module that defines the public file-based API of [`Engine`].
+#![cfg(not(feature = "no_std"))]
+#![cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+
+use crate::types::dynamic::Variant;
+use crate::{Engine, EvalAltResult, Scope, AST};
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Read the contents of a file into a string.
+    fn read_file(path: std::path::PathBuf) -> Result<String, Box<EvalAltResult>> {
+        use std::io::Read;
+
+        let mut f = std::fs::File::open(path.clone()).map_err(|err| {
+            EvalAltResult::ErrorSystem(
+                format!("Cannot open script file '{}'", path.to_string_lossy()),
+                err.into(),
+            )
+        })?;
+
+        let mut contents = String::new();
+
+        f.read_to_string(&mut contents).map_err(|err| {
+            EvalAltResult::ErrorSystem(
+                format!("Cannot read script file '{}'", path.to_string_lossy()),
+                err.into(),
+            )
+        })?;
+
+        if contents.starts_with("#!") {
+            // Remove shebang
+            if let Some(n) = contents.find('\n') {
+                contents.drain(0..n).count();
+            } else {
+                contents.clear();
+            }
+        };
+
+        Ok(contents)
+    }
+    /// Compile a script file into an [`AST`], which can be used later for evaluation.
+    ///
+    /// Not available under `no_std` or `WASM`.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Compile a script file to an AST and store it for later evaluation.
+    /// // Notice that a PathBuf is required which can easily be constructed from a string.
+    /// let ast = engine.compile_file("script.rhai".into())?;
+    ///
+    /// for _ in 0..42 {
+    ///     engine.eval_ast::<i64>(&ast)?;
+    /// }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn compile_file(&self, path: std::path::PathBuf) -> Result<AST, Box<EvalAltResult>> {
+        self.compile_file_with_scope(&Scope::new(), path)
+    }
+    /// Compile a script file into an [`AST`] using own scope, which can be used later for evaluation.
+    ///
+    /// Not available under `no_std` or `WASM`.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_optimize"))]
+    /// # {
+    /// use rhai::{Engine, Scope, OptimizationLevel};
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push_constant("x", 42_i64);   // 'x' is a constant
+    ///
+    /// // Compile a script to an AST and store it for later evaluation.
+    /// // Notice that a PathBuf is required which can easily be constructed from a string.
+    /// let ast = engine.compile_file_with_scope(&mut scope, "script.rhai".into())?;
+    ///
+    /// let result = engine.eval_ast::<i64>(&ast)?;
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn compile_file_with_scope(
+        &self,
+        scope: &Scope,
+        path: std::path::PathBuf,
+    ) -> Result<AST, Box<EvalAltResult>> {
+        Self::read_file(path).and_then(|contents| Ok(self.compile_with_scope(scope, &contents)?))
+    }
+    /// Evaluate a script file.
+    ///
+    /// Not available under `no_std` or `WASM`.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Notice that a PathBuf is required which can easily be constructed from a string.
+    /// let result = engine.eval_file::<i64>("script.rhai".into())?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn eval_file<T: Variant + Clone>(
+        &self,
+        path: std::path::PathBuf,
+    ) -> Result<T, Box<EvalAltResult>> {
+        Self::read_file(path).and_then(|contents| self.eval::<T>(&contents))
+    }
+    /// Evaluate a script file with own scope.
+    ///
+    /// Not available under `no_std` or `WASM`.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::{Engine, Scope};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// // Create initialized scope
+    /// let mut scope = Scope::new();
+    /// scope.push("x", 42_i64);
+    ///
+    /// // Notice that a PathBuf is required which can easily be constructed from a string.
+    /// let result = engine.eval_file_with_scope::<i64>(&mut scope, "script.rhai".into())?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn eval_file_with_scope<T: Variant + Clone>(
+        &self,
+        scope: &mut Scope,
+        path: std::path::PathBuf,
+    ) -> Result<T, Box<EvalAltResult>> {
+        Self::read_file(path).and_then(|contents| self.eval_with_scope(scope, &contents))
+    }
+    /// Evaluate a file, returning any error (if any).
+    ///
+    /// Not available under `no_std` or `WASM`.
+    #[cfg(not(feature = "no_std"))]
+    #[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+    #[inline]
+    pub fn run_file(&self, path: std::path::PathBuf) -> Result<(), Box<EvalAltResult>> {
+        Self::read_file(path).and_then(|contents| self.run(&contents))
+    }
+    /// Evaluate a file with own scope, returning any error (if any).
+    ///
+    /// Not available under `no_std` or `WASM`.
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    #[cfg(not(feature = "no_std"))]
+    #[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+    #[inline]
+    pub fn run_file_with_scope(
+        &self,
+        scope: &mut Scope,
+        path: std::path::PathBuf,
+    ) -> Result<(), Box<EvalAltResult>> {
+        Self::read_file(path).and_then(|contents| self.run_with_scope(scope, &contents))
+    }
+}

src/api/limits.rs

@@ -1,42 +1,90 @@
-//! Configuration settings for [`Engine`].
+//! Settings for [`Engine`]'s limitations.
+#![cfg(not(feature = "unchecked"))]
 
-use crate::tokenizer::Token;
 use crate::Engine;
-use crate::{engine::Precedence, Identifier};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 
-#[cfg(not(feature = "unchecked"))]
 use std::num::{NonZeroU64, NonZeroUsize};
 
+/// A type containing all the limits imposed by the [`Engine`].
+///
+/// Not available under `unchecked`.
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub struct Limits {
+    /// Maximum levels of call-stack to prevent infinite recursion.
+    ///
+    /// Set to zero to effectively disable function calls.
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    pub max_call_stack_depth: usize,
+    /// Maximum depth of statements/expressions at global level.
+    pub max_expr_depth: Option<NonZeroUsize>,
+    /// Maximum depth of statements/expressions in functions.
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    pub max_function_expr_depth: Option<NonZeroUsize>,
+    /// Maximum number of operations allowed to run.
+    pub max_operations: Option<std::num::NonZeroU64>,
+    /// Maximum number of [modules][crate::Module] allowed to load.
+    ///
+    /// Set to zero to effectively disable loading any [module][crate::Module].
+    ///
+    /// Not available under `no_module`.
+    #[cfg(not(feature = "no_module"))]
+    pub max_modules: usize,
+    /// Maximum length of a [string][crate::ImmutableString].
+    pub max_string_size: Option<NonZeroUsize>,
+    /// Maximum length of an [array][crate::Array].
+    ///
+    /// Not available under `no_index`.
+    #[cfg(not(feature = "no_index"))]
+    pub max_array_size: Option<NonZeroUsize>,
+    /// Maximum number of properties in an [object map][crate::Map].
+    ///
+    /// Not available under `no_object`.
+    #[cfg(not(feature = "no_object"))]
+    pub max_map_size: Option<NonZeroUsize>,
+}
+
+impl Limits {
+    /// Create a new [`Limits`] with default values.
+    ///
+    /// Not available under `unchecked`.
+    #[inline]
+    pub const fn new() -> Self {
+        Self {
+            #[cfg(not(feature = "no_function"))]
+            max_call_stack_depth: crate::engine::MAX_CALL_STACK_DEPTH,
+            max_expr_depth: NonZeroUsize::new(crate::engine::MAX_EXPR_DEPTH),
+            #[cfg(not(feature = "no_function"))]
+            max_function_expr_depth: NonZeroUsize::new(crate::engine::MAX_FUNCTION_EXPR_DEPTH),
+            max_operations: None,
+            #[cfg(not(feature = "no_module"))]
+            max_modules: usize::MAX,
+            max_string_size: None,
+            #[cfg(not(feature = "no_index"))]
+            max_array_size: None,
+            #[cfg(not(feature = "no_object"))]
+            max_map_size: None,
+        }
+    }
+}
+
+impl Default for Limits {
+    #[inline(always)]
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Engine {
-    /// Control whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
-    ///
-    /// Not available under `no_optimize`.
-    #[cfg(not(feature = "no_optimize"))]
-    #[inline(always)]
-    pub fn set_optimization_level(
-        &mut self,
-        optimization_level: crate::OptimizationLevel,
-    ) -> &mut Self {
-        self.optimization_level = optimization_level;
-        self
-    }
-    /// The current optimization level.
-    /// It controls whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
-    ///
-    /// Not available under `no_optimize`.
-    #[cfg(not(feature = "no_optimize"))]
-    #[inline(always)]
-    #[must_use]
-    pub const fn optimization_level(&self) -> crate::OptimizationLevel {
-        self.optimization_level
-    }
     /// Set the maximum levels of function calls allowed for a script in order to avoid
     /// infinite recursion and stack overflows.
     ///
     /// Not available under `unchecked` or `no_function`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     pub fn set_max_call_levels(&mut self, levels: usize) -> &mut Self {
@@ -46,7 +94,6 @@ impl Engine {
     /// The maximum levels of function calls allowed for a script.
     ///
     /// Not available under `unchecked` or `no_function`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     #[must_use]
@@ -57,7 +104,6 @@ impl Engine {
     /// consuming too much resources (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline(always)]
     pub fn set_max_operations(&mut self, operations: u64) -> &mut Self {
         self.limits.max_operations = NonZeroU64::new(operations);
@@ -66,7 +112,6 @@ impl Engine {
     /// The maximum number of operations allowed for a script to run (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline]
     #[must_use]
     pub const fn max_operations(&self) -> u64 {
@@ -79,7 +124,6 @@ impl Engine {
     /// Set the maximum number of imported [modules][crate::Module] allowed for a script.
     ///
     /// Not available under `unchecked` or `no_module`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     pub fn set_max_modules(&mut self, modules: usize) -> &mut Self {
@@ -89,7 +133,6 @@ impl Engine {
     /// The maximum number of imported [modules][crate::Module] allowed for a script.
     ///
     /// Not available under `unchecked` or `no_module`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     #[must_use]
@@ -99,7 +142,6 @@ impl Engine {
     /// Set the depth limits for expressions (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline(always)]
     pub fn set_max_expr_depths(
         &mut self,
@@ -116,7 +158,6 @@ impl Engine {
     /// The depth limit for expressions (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline]
     #[must_use]
     pub const fn max_expr_depth(&self) -> usize {
@@ -129,7 +170,6 @@ impl Engine {
     /// The depth limit for expressions in functions (0 for unlimited).
     ///
     /// Not available under `unchecked` or `no_function`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_function"))]
     #[inline]
     #[must_use]
@@ -143,7 +183,6 @@ impl Engine {
     /// Set the maximum length of [strings][crate::ImmutableString] (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline(always)]
     pub fn set_max_string_size(&mut self, max_size: usize) -> &mut Self {
         self.limits.max_string_size = NonZeroUsize::new(max_size);
@@ -152,7 +191,6 @@ impl Engine {
     /// The maximum length of [strings][crate::ImmutableString] (0 for unlimited).
     ///
     /// Not available under `unchecked`.
-    #[cfg(not(feature = "unchecked"))]
     #[inline]
     #[must_use]
     pub const fn max_string_size(&self) -> usize {
@@ -165,7 +203,6 @@ impl Engine {
     /// Set the maximum length of [arrays][crate::Array] (0 for unlimited).
     ///
     /// Not available under `unchecked` or `no_index`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_index"))]
     #[inline(always)]
     pub fn set_max_array_size(&mut self, max_size: usize) -> &mut Self {
@@ -175,7 +212,6 @@ impl Engine {
     /// The maximum length of [arrays][crate::Array] (0 for unlimited).
     ///
     /// Not available under `unchecked` or `no_index`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_index"))]
     #[inline]
     #[must_use]
@@ -189,7 +225,6 @@ impl Engine {
     /// Set the maximum size of [object maps][crate::Map] (0 for unlimited).
     ///
     /// Not available under `unchecked` or `no_object`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
     pub fn set_max_map_size(&mut self, max_size: usize) -> &mut Self {
@@ -199,7 +234,6 @@ impl Engine {
     /// The maximum size of [object maps][crate::Map] (0 for unlimited).
     ///
     /// Not available under `unchecked` or `no_object`.
-    #[cfg(not(feature = "unchecked"))]
     #[cfg(not(feature = "no_object"))]
     #[inline]
     #[must_use]
@@ -210,125 +244,4 @@ impl Engine {
             0
         }
     }
-    /// Set the module resolution service used by the [`Engine`].
-    ///
-    /// Not available under `no_module`.
-    #[cfg(not(feature = "no_module"))]
-    #[inline(always)]
-    pub fn set_module_resolver(
-        &mut self,
-        resolver: impl crate::ModuleResolver + 'static,
-    ) -> &mut Self {
-        self.module_resolver = Some(Box::new(resolver));
-        self
-    }
-    /// Disable a particular keyword or operator in the language.
-    ///
-    /// # Examples
-    ///
-    /// The following will raise an error during parsing because the `if` keyword is disabled
-    /// and is recognized as a reserved symbol!
-    ///
-    /// ```rust,should_panic
-    /// # fn main() -> Result<(), rhai::ParseError> {
-    /// use rhai::Engine;
-    ///
-    /// let mut engine = Engine::new();
-    ///
-    /// engine.disable_symbol("if");    // disable the 'if' keyword
-    ///
-    /// engine.compile("let x = if true { 42 } else { 0 };")?;
-    /// //                      ^ 'if' is rejected as a reserved symbol
-    /// # Ok(())
-    /// # }
-    /// ```
-    ///
-    /// The following will raise an error during parsing because the `+=` operator is disabled.
-    ///
-    /// ```rust,should_panic
-    /// # fn main() -> Result<(), rhai::ParseError> {
-    /// use rhai::Engine;
-    ///
-    /// let mut engine = Engine::new();
-    ///
-    /// engine.disable_symbol("+=");    // disable the '+=' operator
-    ///
-    /// engine.compile("let x = 42; x += 1;")?;
-    /// //                            ^ unknown operator
-    /// # Ok(())
-    /// # }
-    /// ```
-    #[inline(always)]
-    pub fn disable_symbol(&mut self, symbol: impl Into<Identifier>) -> &mut Self {
-        self.disabled_symbols.insert(symbol.into());
-        self
-    }
-    /// Register a custom operator with a precedence into the language.
-    ///
-    /// The operator must be a valid identifier (i.e. it cannot be a symbol).
-    ///
-    /// The precedence cannot be zero.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-    /// use rhai::Engine;
-    ///
-    /// let mut engine = Engine::new();
-    ///
-    /// // Register a custom operator called 'foo' and give it
-    /// // a precedence of 160 (i.e. between +|- and *|/).
-    /// engine.register_custom_operator("foo", 160).expect("should succeed");
-    ///
-    /// // Register a binary function named 'foo'
-    /// engine.register_fn("foo", |x: i64, y: i64| (x * y) - (x + y));
-    ///
-    /// assert_eq!(
-    ///     engine.eval_expression::<i64>("1 + 2 * 3 foo 4 - 5 / 6")?,
-    ///     15
-    /// );
-    /// # Ok(())
-    /// # }
-    /// ```
-    pub fn register_custom_operator(
-        &mut self,
-        keyword: impl AsRef<str> + Into<Identifier>,
-        precedence: u8,
-    ) -> Result<&mut Self, String> {
-        let precedence = Precedence::new(precedence);
-
-        if precedence.is_none() {
-            return Err("precedence cannot be zero".into());
-        }
-
-        match Token::lookup_from_syntax(keyword.as_ref()) {
-            // Standard identifiers, reserved keywords and custom keywords are OK
-            None | Some(Token::Reserved(_)) | Some(Token::Custom(_)) => (),
-            // Active standard keywords cannot be made custom
-            // Disabled keywords are OK
-            Some(token) if token.is_standard_keyword() => {
-                if !self.disabled_symbols.contains(&*token.syntax()) {
-                    return Err(format!("'{}' is a reserved keyword", keyword.as_ref()));
-                }
-            }
-            // Active standard symbols cannot be made custom
-            Some(token) if token.is_standard_symbol() => {
-                if !self.disabled_symbols.contains(&*token.syntax()) {
-                    return Err(format!("'{}' is a reserved operator", keyword.as_ref()));
-                }
-            }
-            // Active standard symbols cannot be made custom
-            Some(token) if !self.disabled_symbols.contains(&*token.syntax()) => {
-                return Err(format!("'{}' is a reserved symbol", keyword.as_ref()))
-            }
-            // Disabled symbols are OK
-            Some(_) => (),
-        }
-
-        // Add to custom keywords
-        self.custom_keywords.insert(keyword.into(), precedence);
-
-        Ok(self)
-    }
 }

src/api/mod.rs

@@ -1,5 +1,226 @@
 //! Module defining the public API of the Rhai engine.
 
+pub mod eval;
+
+pub mod run;
+
+pub mod compile;
+
+pub mod files;
+
+pub mod register;
+
+pub mod call_fn;
+
+pub mod options;
+
+pub mod limits;
+
+pub mod events;
+
 pub mod deprecated;
-pub mod public;
+
-pub mod settings;
+use crate::engine::Precedence;
+use crate::tokenizer::Token;
+use crate::{Engine, Identifier};
+
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+/// Script optimization API.
+#[cfg(not(feature = "no_optimize"))]
+impl Engine {
+    /// Control whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
+    ///
+    /// Not available under `no_optimize`.
+    #[inline(always)]
+    pub fn set_optimization_level(
+        &mut self,
+        optimization_level: crate::OptimizationLevel,
+    ) -> &mut Self {
+        self.optimization_level = optimization_level;
+        self
+    }
+    /// The current optimization level.
+    /// It controls whether and how the [`Engine`] will optimize an [`AST`][crate::AST] after compilation.
+    ///
+    /// Not available under `no_optimize`.
+    #[inline(always)]
+    #[must_use]
+    pub const fn optimization_level(&self) -> crate::OptimizationLevel {
+        self.optimization_level
+    }
+    /// Optimize the [`AST`][crate::AST] with constants defined in an external Scope. An optimized
+    /// copy of the [`AST`][crate::AST] is returned while the original [`AST`][crate::AST] is consumed.
+    ///
+    /// Not available under `no_optimize`.
+    ///
+    /// Although optimization is performed by default during compilation, sometimes it is necessary
+    /// to _re_-optimize an [`AST`][crate::AST]. For example, when working with constants that are
+    /// passed in via an external scope, it will be more efficient to optimize the
+    /// [`AST`][crate::AST] once again to take advantage of the new constants.
+    ///
+    /// With this method, it is no longer necessary to recompile a large script. The script
+    /// [`AST`][crate::AST] can be compiled just once. Before evaluation, constants are passed into
+    /// the [`Engine`] via an external scope (i.e. with
+    /// [`Scope::push_constant`][crate::Scope::push_constant]). Then, the [`AST`][crate::AST] is
+    /// cloned and the copy re-optimized before running.
+    #[inline]
+    #[must_use]
+    pub fn optimize_ast(
+        &self,
+        scope: &crate::Scope,
+        ast: crate::AST,
+        optimization_level: crate::OptimizationLevel,
+    ) -> crate::AST {
+        let mut ast = ast;
+
+        #[cfg(not(feature = "no_function"))]
+        let lib = ast
+            .shared_lib()
+            .iter_fn()
+            .filter(|f| f.func.is_script())
+            .map(|f| {
+                f.func
+                    .get_script_fn_def()
+                    .expect("scripted function")
+                    .clone()
+            })
+            .collect();
+
+        let statements = std::mem::take(ast.statements_mut());
+
+        crate::optimizer::optimize_into_ast(
+            self,
+            scope,
+            statements,
+            #[cfg(not(feature = "no_function"))]
+            lib,
+            optimization_level,
+        )
+    }
+}
+
+impl Engine {
+    /// Set the module resolution service used by the [`Engine`].
+    ///
+    /// Not available under `no_module`.
+    #[cfg(not(feature = "no_module"))]
+    #[inline(always)]
+    pub fn set_module_resolver(
+        &mut self,
+        resolver: impl crate::ModuleResolver + 'static,
+    ) -> &mut Self {
+        self.module_resolver = Some(Box::new(resolver));
+        self
+    }
+    /// Disable a particular keyword or operator in the language.
+    ///
+    /// # Examples
+    ///
+    /// The following will raise an error during parsing because the `if` keyword is disabled
+    /// and is recognized as a reserved symbol!
+    ///
+    /// ```rust,should_panic
+    /// # fn main() -> Result<(), rhai::ParseError> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// engine.disable_symbol("if");    // disable the 'if' keyword
+    ///
+    /// engine.compile("let x = if true { 42 } else { 0 };")?;
+    /// //                      ^ 'if' is rejected as a reserved symbol
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// The following will raise an error during parsing because the `+=` operator is disabled.
+    ///
+    /// ```rust,should_panic
+    /// # fn main() -> Result<(), rhai::ParseError> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// engine.disable_symbol("+=");    // disable the '+=' operator
+    ///
+    /// engine.compile("let x = 42; x += 1;")?;
+    /// //                            ^ unknown operator
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline(always)]
+    pub fn disable_symbol(&mut self, symbol: impl Into<Identifier>) -> &mut Self {
+        self.disabled_symbols.insert(symbol.into());
+        self
+    }
+    /// Register a custom operator with a precedence into the language.
+    ///
+    /// The operator must be a valid identifier (i.e. it cannot be a symbol).
+    ///
+    /// The precedence cannot be zero.
+    ///
+    /// # Example
+    ///
+    /// ```rust
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// use rhai::Engine;
+    ///
+    /// let mut engine = Engine::new();
+    ///
+    /// // Register a custom operator called 'foo' and give it
+    /// // a precedence of 160 (i.e. between +|- and *|/).
+    /// engine.register_custom_operator("foo", 160).expect("should succeed");
+    ///
+    /// // Register a binary function named 'foo'
+    /// engine.register_fn("foo", |x: i64, y: i64| (x * y) - (x + y));
+    ///
+    /// assert_eq!(
+    ///     engine.eval_expression::<i64>("1 + 2 * 3 foo 4 - 5 / 6")?,
+    ///     15
+    /// );
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn register_custom_operator(
+        &mut self,
+        keyword: impl AsRef<str> + Into<Identifier>,
+        precedence: u8,
+    ) -> Result<&mut Self, String> {
+        let precedence = Precedence::new(precedence);
+
+        if precedence.is_none() {
+            return Err("precedence cannot be zero".into());
+        }
+
+        match Token::lookup_from_syntax(keyword.as_ref()) {
+            // Standard identifiers, reserved keywords and custom keywords are OK
+            None | Some(Token::Reserved(_)) | Some(Token::Custom(_)) => (),
+            // Active standard keywords cannot be made custom
+            // Disabled keywords are OK
+            Some(token) if token.is_standard_keyword() => {
+                if !self.disabled_symbols.contains(&*token.syntax()) {
+                    return Err(format!("'{}' is a reserved keyword", keyword.as_ref()));
+                }
+            }
+            // Active standard symbols cannot be made custom
+            Some(token) if token.is_standard_symbol() => {
+                if !self.disabled_symbols.contains(&*token.syntax()) {
+                    return Err(format!("'{}' is a reserved operator", keyword.as_ref()));
+                }
+            }
+            // Active standard symbols cannot be made custom
+            Some(token) if !self.disabled_symbols.contains(&*token.syntax()) => {
+                return Err(format!("'{}' is a reserved symbol", keyword.as_ref()))
+            }
+            // Disabled symbols are OK
+            Some(_) => (),
+        }
+
+        // Add to custom keywords
+        self.custom_keywords.insert(keyword.into(), precedence);
+
+        Ok(self)
+    }
+}

src/api/options.rs

@@ -0,0 +1,114 @@
+//! Settings for [`Engine`]'s language options.
+
+use crate::Engine;
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+/// A type containing all language options for the [`Engine`].
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub struct LanguageOptions {
+    /// Is `if`-expression allowed?
+    pub allow_if_expr: bool,
+    /// Is `switch` expression allowed?
+    pub allow_switch_expr: bool,
+    /// Is statement-expression allowed?
+    pub allow_stmt_expr: bool,
+    /// Is anonymous function allowed?
+    #[cfg(not(feature = "no_function"))]
+    pub allow_anonymous_fn: bool,
+    /// Is looping allowed?
+    pub allow_loop: bool,
+    /// Strict variables mode?
+    pub strict_var: bool,
+}
+
+impl LanguageOptions {
+    /// Create a new [`Options`] with default values.
+    #[inline(always)]
+    pub const fn new() -> Self {
+        Self {
+            allow_if_expr: true,
+            allow_switch_expr: true,
+            allow_stmt_expr: true,
+            #[cfg(not(feature = "no_function"))]
+            allow_anonymous_fn: true,
+            allow_loop: true,
+            strict_var: false,
+        }
+    }
+}
+
+impl Default for LanguageOptions {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Engine {
+    /// Is `if`-expression allowed?
+    #[inline(always)]
+    pub fn allow_if_expression(&self) -> bool {
+        self.options.allow_if_expr
+    }
+    /// Set whether `if`-expression is allowed.
+    #[inline(always)]
+    pub fn set_allow_if_expression(&mut self, enable: bool) {
+        self.options.allow_if_expr = enable;
+    }
+    /// Is `switch` expression allowed?
+    #[inline(always)]
+    pub fn allow_switch_expression(&self) -> bool {
+        self.options.allow_switch_expr
+    }
+    /// Set whether `switch` expression is allowed.
+    #[inline(always)]
+    pub fn set_allow_switch_expression(&mut self, enable: bool) {
+        self.options.allow_switch_expr = enable;
+    }
+    /// Is statement-expression allowed?
+    #[inline(always)]
+    pub fn allow_statement_expression(&self) -> bool {
+        self.options.allow_stmt_expr
+    }
+    /// Set whether statement-expression is allowed.
+    #[inline(always)]
+    pub fn set_allow_statement_expression(&mut self, enable: bool) {
+        self.options.allow_stmt_expr = enable;
+    }
+    /// Is anonymous function allowed?
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
+    pub fn allow_anonymous_fn(&self) -> bool {
+        self.options.allow_anonymous_fn
+    }
+    /// Set whether anonymous function is allowed.
+    ///
+    /// Not available under `no_function`.
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
+    pub fn set_allow_anonymous_fn(&mut self, enable: bool) {
+        self.options.allow_anonymous_fn = enable;
+    }
+    /// Is looping allowed?
+    #[inline(always)]
+    pub fn allow_looping(&self) -> bool {
+        self.options.allow_loop
+    }
+    /// Set whether looping is allowed.
+    #[inline(always)]
+    pub fn set_allow_looping(&mut self, enable: bool) {
+        self.options.allow_loop = enable;
+    }
+    /// Is strict variables mode enabled?
+    #[inline(always)]
+    pub fn strict_variables(&self) -> bool {
+        self.options.strict_var
+    }
+    /// Set whether strict variables mode is enabled.
+    #[inline(always)]
+    pub fn set_strict_variables(&mut self, enable: bool) {
+        self.options.strict_var = enable;
+    }
+}

src/api/run.rs

@@ -0,0 +1,80 @@
+//! Module that defines the public evaluation API of [`Engine`].
+
+use crate::engine::{EvalState, Imports};
+use crate::parser::ParseState;
+use crate::{Engine, EvalAltResult, Module, Scope, AST};
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Evaluate a script, returning any error (if any).
+    #[inline(always)]
+    pub fn run(&self, script: &str) -> Result<(), Box<EvalAltResult>> {
+        self.run_with_scope(&mut Scope::new(), script)
+    }
+    /// Evaluate a script with own scope, returning any error (if any).
+    ///
+    /// ## Constants Propagation
+    ///
+    /// If not [`OptimizationLevel::None`][crate::OptimizationLevel::None], constants defined within
+    /// the scope are propagated throughout the script _including_ functions. This allows functions
+    /// to be optimized based on dynamic global constants.
+    #[inline]
+    pub fn run_with_scope(
+        &self,
+        scope: &mut Scope,
+        script: &str,
+    ) -> Result<(), Box<EvalAltResult>> {
+        let scripts = [script];
+        let (stream, tokenizer_control) =
+            self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
+        let mut state = ParseState::new(self, tokenizer_control);
+
+        let ast = self.parse(
+            &mut stream.peekable(),
+            &mut state,
+            scope,
+            #[cfg(not(feature = "no_optimize"))]
+            self.optimization_level,
+        )?;
+
+        self.run_ast_with_scope(scope, &ast)
+    }
+    /// Evaluate an [`AST`], returning any error (if any).
+    #[inline(always)]
+    pub fn run_ast(&self, ast: &AST) -> Result<(), Box<EvalAltResult>> {
+        self.run_ast_with_scope(&mut Scope::new(), ast)
+    }
+    /// Evaluate an [`AST`] with own scope, returning any error (if any).
+    #[inline]
+    pub fn run_ast_with_scope(
+        &self,
+        scope: &mut Scope,
+        ast: &AST,
+    ) -> Result<(), Box<EvalAltResult>> {
+        let mods = &mut Imports::new();
+        let mut state = EvalState::new();
+        if ast.source_raw().is_some() {
+            mods.source = ast.source_raw().cloned();
+        }
+        #[cfg(not(feature = "no_module"))]
+        {
+            mods.embedded_module_resolver = ast.resolver().cloned();
+        }
+
+        let statements = ast.statements();
+        if !statements.is_empty() {
+            let lib = [
+                #[cfg(not(feature = "no_function"))]
+                ast.as_ref(),
+            ];
+            let lib = if lib.first().map(|m: &&Module| m.is_empty()).unwrap_or(true) {
+                &lib[0..0]
+            } else {
+                &lib
+            };
+            self.eval_global_statements(scope, mods, &mut state, statements, lib, 0)?;
+        }
+        Ok(())
+    }
+}

src/ast.rs

@@ -1,7 +1,6 @@
 //! Module defining the AST (abstract syntax tree).
 
 use crate::calc_fn_hash;
-use crate::func::native::shared_make_mut;
 use crate::module::NamespaceRef;
 use crate::tokenizer::Token;
 use crate::types::dynamic::Union;
@@ -45,10 +44,6 @@ pub enum FnAccess {
 
 /// _(internals)_ A type containing information on a scripted function.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone)]
 pub struct ScriptFnDef {
     /// Function body.
@@ -68,9 +63,6 @@ pub struct ScriptFnDef {
     pub params: StaticVec<Identifier>,
     /// _(metadata)_ Function doc-comments (if any).
     /// Exported under the `metadata` feature only.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(not(feature = "no_function"))]
     #[cfg(feature = "metadata")]
     pub comments: Option<Box<[Box<str>]>>,
 }
@@ -105,15 +97,12 @@ pub struct ScriptFnMetadata<'a> {
     /// _(metadata)_ Function doc-comments (if any).
     /// Exported under the `metadata` feature only.
     ///
-    /// Not available under `no_function`.
-    ///
     /// Block doc-comments are kept in a single string slice with line-breaks within.
     ///
     /// Line doc-comments are kept in one string slice per line without the termination line-break.
     ///
     /// Leading white-spaces are stripped, and each string slice always starts with the corresponding
     /// doc-comment leader: `///` or `/**`.
-    #[cfg(not(feature = "no_function"))]
     #[cfg(feature = "metadata")]
     pub comments: Vec<&'a str>,
     /// Function access mode.
@@ -191,10 +180,9 @@ pub struct AST {
     /// Global statements.
     body: StmtBlock,
     /// Script-defined functions.
+    #[cfg(not(feature = "no_function"))]
     functions: Shared<Module>,
     /// Embedded module resolver, if any.
-    ///
-    /// Not available under `no_module`.
     #[cfg(not(feature = "no_module"))]
     resolver: Option<Shared<crate::module::resolvers::StaticModuleResolver>>,
 }
@@ -208,48 +196,88 @@ impl Default for AST {
 
 impl AST {
     /// Create a new [`AST`].
-    #[inline]
+    #[cfg(not(feature = "internals"))]
+    #[inline(always)]
     #[must_use]
-    pub fn new(
+    pub(crate) fn new(
         statements: impl IntoIterator<Item = Stmt>,
-        functions: impl Into<Shared<Module>>,
+        #[cfg(not(feature = "no_function"))] functions: impl Into<Shared<Module>>,
     ) -> Self {
         Self {
             source: None,
             body: StmtBlock::new(statements, Position::NONE),
+            #[cfg(not(feature = "no_function"))]
             functions: functions.into(),
             #[cfg(not(feature = "no_module"))]
             resolver: None,
         }
     }
+    /// _(internals)_ Create a new [`AST`].
+    /// Exported under the `internals` feature only.
+    #[cfg(feature = "internals")]
+    #[inline(always)]
+    #[must_use]
+    pub fn new(
+        statements: impl IntoIterator<Item = Stmt>,
+        #[cfg(not(feature = "no_function"))] functions: impl Into<Shared<Module>>,
+    ) -> Self {
+        Self {
+            source: None,
+            body: StmtBlock::new(statements, Position::NONE),
+            #[cfg(not(feature = "no_function"))]
+            functions: functions.into(),
+            #[cfg(not(feature = "no_module"))]
+            resolver: None,
+        }
+    }
+    /// Create a new [`AST`] with a source name.
+    #[cfg(not(feature = "internals"))]
+    #[inline(always)]
+    #[must_use]
+    pub(crate) fn new_with_source(
+        statements: impl IntoIterator<Item = Stmt>,
+        #[cfg(not(feature = "no_function"))] functions: impl Into<Shared<Module>>,
+        source: impl Into<Identifier>,
+    ) -> Self {
+        let mut ast = Self::new(
+            statements,
+            #[cfg(not(feature = "no_function"))]
+            functions,
+        );
+        ast.set_source(source);
+        ast
+    }
+    /// _(internals)_ Create a new [`AST`] with a source name.
+    /// Exported under the `internals` feature only.
+    #[cfg(feature = "internals")]
+    #[inline(always)]
+    #[must_use]
+    pub fn new_with_source(
+        statements: impl IntoIterator<Item = Stmt>,
+        #[cfg(not(feature = "no_function"))] functions: impl Into<Shared<Module>>,
+        source: impl Into<Identifier>,
+    ) -> Self {
+        let mut ast = Self::new(
+            statements,
+            #[cfg(not(feature = "no_function"))]
+            functions,
+        );
+        ast.set_source(source);
+        ast
+    }
     /// Create an empty [`AST`].
     #[inline]
     #[must_use]
     pub fn empty() -> Self {
         Self {
             source: None,
-            body: StmtBlock::empty(),
+            body: StmtBlock::NONE,
+            #[cfg(not(feature = "no_function"))]
             functions: Module::new().into(),
             #[cfg(not(feature = "no_module"))]
             resolver: None,
         }
     }
-    /// Create a new [`AST`] with a source name.
-    #[inline(always)]
-    #[must_use]
-    pub fn new_with_source(
-        statements: impl IntoIterator<Item = Stmt>,
-        functions: impl Into<Shared<Module>>,
-        source: impl Into<Identifier>,
-    ) -> Self {
-        Self {
-            source: Some(source.into()),
-            body: StmtBlock::new(statements, Position::NONE),
-            functions: functions.into(),
-            #[cfg(not(feature = "no_module"))]
-            resolver: None,
-        }
-    }
     /// Get the source, if any.
     #[inline(always)]
     #[must_use]
@@ -266,6 +294,7 @@ impl AST {
     #[inline]
     pub fn set_source(&mut self, source: impl Into<Identifier>) -> &mut Self {
         let source = source.into();
+        #[cfg(not(feature = "no_function"))]
         Shared::get_mut(&mut self.functions)
             .as_mut()
             .map(|m| m.set_id(source.clone()));
@@ -288,79 +317,66 @@ impl AST {
     /// _(internals)_ Get the statements.
     /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
-    #[deprecated = "this method is volatile and may change"]
     #[inline(always)]
     #[must_use]
     pub fn statements(&self) -> &[Stmt] {
         &self.body.0
     }
     /// Get a mutable reference to the statements.
-    #[cfg(not(feature = "no_optimize"))]
+    #[allow(dead_code)]
     #[inline(always)]
     #[must_use]
     pub(crate) fn statements_mut(&mut self) -> &mut StaticVec<Stmt> {
         &mut self.body.0
     }
-    /// Get the internal shared [`Module`] containing all script-defined functions.
+    /// Does this [`AST`] contain script-defined functions?
-    #[cfg(not(feature = "internals"))]
+    ///
-    #[cfg(not(feature = "no_module"))]
+    /// Not available under `no_function`.
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     #[must_use]
-    pub(crate) fn shared_lib(&self) -> Shared<Module> {
+    pub fn has_functions(&self) -> bool {
-        self.functions.clone()
+        !self.functions.is_empty()
+    }
+    /// Get the internal shared [`Module`] containing all script-defined functions.
+    #[cfg(not(feature = "internals"))]
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
+    #[must_use]
+    pub(crate) fn shared_lib(&self) -> &Shared<Module> {
+        &self.functions
     }
     /// _(internals)_ Get the internal shared [`Module`] containing all script-defined functions.
     /// Exported under the `internals` feature only.
     ///
-    /// Not available under `no_function` or `no_module`.
+    /// Not available under `no_function`.
     #[cfg(feature = "internals")]
-    #[deprecated = "this method is volatile and may change"]
-    #[cfg(not(feature = "no_module"))]
     #[cfg(not(feature = "no_function"))]
     #[inline(always)]
     #[must_use]
-    pub fn shared_lib(&self) -> Shared<Module> {
+    pub fn shared_lib(&self) -> &Shared<Module> {
-        self.functions.clone()
-    }
-    /// Get the internal [`Module`] containing all script-defined functions.
-    #[cfg(not(feature = "internals"))]
-    #[inline(always)]
-    #[must_use]
-    pub(crate) fn lib(&self) -> &Module {
-        &self.functions
-    }
-    /// _(internals)_ Get the internal [`Module`] containing all script-defined functions.
-    /// Exported under the `internals` feature only.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(feature = "internals")]
-    #[deprecated = "this method is volatile and may change"]
-    #[inline(always)]
-    #[must_use]
-    pub fn lib(&self) -> &Module {
         &self.functions
     }
     /// Get the embedded [module resolver][`ModuleResolver`].
-    #[cfg(not(feature = "no_module"))]
     #[cfg(not(feature = "internals"))]
+    #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     #[must_use]
     pub(crate) fn resolver(
         &self,
-    ) -> Option<Shared<crate::module::resolvers::StaticModuleResolver>> {
+    ) -> Option<&Shared<crate::module::resolvers::StaticModuleResolver>> {
-        self.resolver.clone()
+        self.resolver.as_ref()
     }
     /// _(internals)_ Get the embedded [module resolver][crate::ModuleResolver].
     /// Exported under the `internals` feature only.
     ///
     /// Not available under `no_module`.
-    #[cfg(not(feature = "no_module"))]
     #[cfg(feature = "internals")]
+    #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     #[must_use]
-    pub fn resolver(&self) -> Option<Shared<crate::module::resolvers::StaticModuleResolver>> {
+    pub fn resolver(&self) -> Option<&Shared<crate::module::resolvers::StaticModuleResolver>> {
-        self.resolver.clone()
+        self.resolver.as_ref()
     }
     /// Set the embedded [module resolver][`ModuleResolver`].
     #[cfg(not(feature = "no_module"))]
@@ -401,7 +417,7 @@ impl AST {
         functions.merge_filtered(&self.functions, &filter);
         Self {
             source: self.source.clone(),
-            body: StmtBlock::empty(),
+            body: StmtBlock::NONE,
             functions: functions.into(),
             #[cfg(not(feature = "no_module"))]
             resolver: self.resolver.clone(),
@@ -415,6 +431,7 @@ impl AST {
         Self {
             source: self.source.clone(),
             body: self.body.clone(),
+            #[cfg(not(feature = "no_function"))]
             functions: Module::new().into(),
             #[cfg(not(feature = "no_module"))]
             resolver: self.resolver.clone(),
@@ -472,7 +489,7 @@ impl AST {
     #[inline(always)]
     #[must_use]
     pub fn merge(&self, other: &Self) -> Self {
-        self.merge_filtered(other, |_, _, _, _, _| true)
+        self.merge_filtered_impl(other, |_, _, _, _, _| true)
     }
     /// Combine one [`AST`] with another.  The second [`AST`] is consumed.
     ///
@@ -524,11 +541,13 @@ impl AST {
     /// ```
     #[inline(always)]
     pub fn combine(&mut self, other: Self) -> &mut Self {
-        self.combine_filtered(other, |_, _, _, _, _| true)
+        self.combine_filtered_impl(other, |_, _, _, _, _| true)
     }
     /// Merge two [`AST`] into one.  Both [`AST`]'s are untouched and a new, merged, version
     /// is returned.
     ///
+    /// Not available under `no_function`.
+    ///
     /// Statements in the second [`AST`] are simply appended to the end of the first _without any processing_.
     /// Thus, the return value of the first [`AST`] (if using expression-statement syntax) is buried.
     /// Of course, if the first [`AST`] uses a `return` statement at the end, then
@@ -542,8 +561,6 @@ impl AST {
     ///
     /// ```
     /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-    /// # #[cfg(not(feature = "no_function"))]
-    /// # {
     /// use rhai::Engine;
     ///
     /// let engine = Engine::new();
@@ -574,45 +591,67 @@ impl AST {
     ///
     /// // Evaluate it
     /// assert_eq!(engine.eval_ast::<String>(&ast)?, "42!");
-    /// # }
     /// # Ok(())
     /// # }
     /// ```
-    #[inline]
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
     #[must_use]
     pub fn merge_filtered(
         &self,
         other: &Self,
         filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool,
     ) -> Self {
-        let Self {
+        self.merge_filtered_impl(other, filter)
-            body, functions, ..
+    }
-        } = self;
+    /// Merge two [`AST`] into one.  Both [`AST`]'s are untouched and a new, merged, version
-
+    /// is returned.
-        let merged = match (body.is_empty(), other.body.is_empty()) {
+    #[inline]
+    #[must_use]
+    fn merge_filtered_impl(
+        &self,
+        other: &Self,
+        _filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool,
+    ) -> Self {
+        let merged = match (self.body.is_empty(), other.body.is_empty()) {
             (false, false) => {
-                let mut body = body.clone();
+                let mut body = self.body.clone();
                 body.0.extend(other.body.0.iter().cloned());
                 body
             }
-            (false, true) => body.clone(),
+            (false, true) => self.body.clone(),
             (true, false) => other.body.clone(),
-            (true, true) => StmtBlock::empty(),
+            (true, true) => StmtBlock::NONE,
         };
 
         let source = other.source.clone().or_else(|| self.source.clone());
 
-        let mut functions = functions.as_ref().clone();
+        #[cfg(not(feature = "no_function"))]
-        functions.merge_filtered(&other.functions, &filter);
+        let functions = {
+            let mut functions = self.functions.as_ref().clone();
+            functions.merge_filtered(&other.functions, &_filter);
+            functions
+        };
 
         if let Some(source) = source {
-            Self::new_with_source(merged.0, functions, source)
+            Self::new_with_source(
+                merged.0,
+                #[cfg(not(feature = "no_function"))]
+                functions,
+                source,
+            )
         } else {
-            Self::new(merged.0, functions)
+            Self::new(
+                merged.0,
+                #[cfg(not(feature = "no_function"))]
+                functions,
+            )
         }
     }
     /// Combine one [`AST`] with another.  The second [`AST`] is consumed.
     ///
+    /// Not available under `no_function`.
+    ///
     /// Statements in the second [`AST`] are simply appended to the end of the first _without any processing_.
     /// Thus, the return value of the first [`AST`] (if using expression-statement syntax) is buried.
     /// Of course, if the first [`AST`] uses a `return` statement at the end, then
@@ -626,8 +665,6 @@ impl AST {
     ///
     /// ```
     /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-    /// # #[cfg(not(feature = "no_function"))]
-    /// # {
     /// use rhai::Engine;
     ///
     /// let engine = Engine::new();
@@ -658,20 +695,31 @@ impl AST {
     ///
     /// // Evaluate it
     /// assert_eq!(engine.eval_ast::<String>(&ast1)?, "42!");
-    /// # }
     /// # Ok(())
     /// # }
     /// ```
-    #[inline]
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
     pub fn combine_filtered(
         &mut self,
         other: Self,
         filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool,
+    ) -> &mut Self {
+        self.combine_filtered_impl(other, filter)
+    }
+    /// Combine one [`AST`] with another.  The second [`AST`] is consumed.
+    #[inline]
+    fn combine_filtered_impl(
+        &mut self,
+        other: Self,
+        _filter: impl Fn(FnNamespace, FnAccess, bool, &str, usize) -> bool,
     ) -> &mut Self {
         self.body.0.extend(other.body.0.into_iter());
 
+        #[cfg(not(feature = "no_function"))]
         if !other.functions.is_empty() {
-            shared_make_mut(&mut self.functions).merge_filtered(&other.functions, &filter);
+            crate::func::native::shared_make_mut(&mut self.functions)
+                .merge_filtered(&other.functions, &_filter);
         }
         self
     }
@@ -707,7 +755,8 @@ impl AST {
         filter: impl Fn(FnNamespace, FnAccess, &str, usize) -> bool,
     ) -> &mut Self {
         if !self.functions.is_empty() {
-            shared_make_mut(&mut self.functions).retain_script_functions(filter);
+            crate::func::native::shared_make_mut(&mut self.functions)
+                .retain_script_functions(filter);
         }
         self
     }
@@ -744,7 +793,7 @@ impl AST {
     /// Clear all statements in the [`AST`], leaving only function definitions.
     #[inline(always)]
     pub fn clear_statements(&mut self) -> &mut Self {
-        self.body = StmtBlock::empty();
+        self.body = StmtBlock::NONE;
         self
     }
     /// Extract all top-level literal constant and/or variable definitions.
@@ -899,19 +948,24 @@ impl AsRef<[Stmt]> for AST {
     }
 }
 
+#[cfg(not(feature = "no_function"))]
 impl AsRef<Module> for AST {
     #[inline(always)]
     fn as_ref(&self) -> &Module {
-        self.lib()
+        self.shared_lib().as_ref()
+    }
+}
+
+#[cfg(not(feature = "no_function"))]
+impl AsRef<Shared<Module>> for AST {
+    #[inline(always)]
+    fn as_ref(&self) -> &Shared<Module> {
+        self.shared_lib()
     }
 }
 
 /// _(internals)_ An identifier containing a name and a [position][Position].
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Clone, Eq, PartialEq, Hash)]
 pub struct Ident {
     /// Identifier name.
@@ -943,10 +997,6 @@ impl Ident {
 
 /// _(internals)_ An [`AST`] node, consisting of either an [`Expr`] or a [`Stmt`].
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Hash)]
 pub enum ASTNode<'a> {
     /// A statement ([`Stmt`]).
@@ -979,14 +1029,13 @@ impl ASTNode<'_> {
 
 /// _(internals)_ A scoped block of statements.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Clone, Hash, Default)]
 pub struct StmtBlock(StaticVec<Stmt>, Position);
 
 impl StmtBlock {
+    /// A [`StmtBlock`] that does not exist.
+    pub const NONE: Self = Self::empty(Position::NONE);
+
     /// Create a new [`StmtBlock`].
     #[must_use]
     pub fn new(statements: impl IntoIterator<Item = Stmt>, pos: Position) -> Self {
@@ -997,8 +1046,8 @@ impl StmtBlock {
     /// Create an empty [`StmtBlock`].
     #[inline(always)]
     #[must_use]
-    pub fn empty() -> Self {
+    pub const fn empty(pos: Position) -> Self {
-        Default::default()
+        Self(StaticVec::new_const(), pos)
     }
     /// Is this statements block empty?
     #[inline(always)]
@@ -1209,10 +1258,6 @@ pub mod AST_OPTION_FLAGS {
 
 /// _(internals)_ A statement.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Hash)]
 pub enum Stmt {
     /// No-op.
@@ -1306,7 +1351,7 @@ impl From<Stmt> for StmtBlock {
     fn from(stmt: Stmt) -> Self {
         match stmt {
             Stmt::Block(mut block, pos) => Self(block.iter_mut().map(mem::take).collect(), pos),
-            Stmt::Noop(pos) => Self(StaticVec::new(), pos),
+            Stmt::Noop(pos) => Self(StaticVec::new_const(), pos),
             _ => {
                 let pos = stmt.position();
                 Self(vec![stmt].into(), pos)
@@ -1659,10 +1704,6 @@ impl Stmt {
 
 /// _(internals)_ A custom syntax expression.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Hash)]
 pub struct CustomExpr {
     /// List of keywords.
@@ -1689,10 +1730,6 @@ impl CustomExpr {
 
 /// _(internals)_ A binary expression.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Hash)]
 pub struct BinaryExpr {
     /// LHS expression.
@@ -1703,10 +1740,6 @@ pub struct BinaryExpr {
 
 /// _(internals)_ An op-assignment operator.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub struct OpAssignment<'a> {
     /// Hash of the op-assignment call.
@@ -1764,10 +1797,6 @@ impl OpAssignment<'_> {
 ///   then used to search for a native function. In other words, a complete native function call
 ///   hash always contains the called function's name plus the types of the arguments.  This is due
 ///   to possible function overloading for different parameter types.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Clone, Copy, Eq, PartialEq, Hash, Default)]
 pub struct FnCallHashes {
     /// Pre-calculated hash for a script-defined function ([`None`] if native functions only).
@@ -1838,10 +1867,6 @@ impl FnCallHashes {
 
 /// _(internals)_ A function call.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Default, Hash)]
 pub struct FnCallExpr {
     /// Namespace of the function, if any.
@@ -1862,7 +1887,7 @@ pub struct FnCallExpr {
     /// Constant arguments are very common in function calls, and keeping each constant in
     /// an [`Expr::DynamicConstant`] involves an additional allocation.  Keeping the constant
     /// values in an inlined array avoids these extra allocations.
-    pub constants: smallvec::SmallVec<[Dynamic; 2]>,
+    pub constants: StaticVec<Dynamic>,
     /// Does this function call capture the parent scope?
     pub capture_parent_scope: bool,
 }
@@ -2005,10 +2030,6 @@ impl FloatWrapper<FLOAT> {
 
 /// _(internals)_ An expression sub-tree.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Clone, Hash)]
 pub enum Expr {
     /// Dynamic constant.
@@ -2496,3 +2517,24 @@ impl Expr {
         true
     }
 }
+
+impl AST {
+    /// _(internals)_ Get the internal [`Module`] containing all script-defined functions.
+    /// Exported under the `internals` feature only.
+    ///
+    /// Not available under `no_function`.
+    ///
+    /// # Deprecated
+    ///
+    /// This method is deprecated. Use [`shared_lib`][AST::shared_lib] instead.
+    ///
+    /// This method will be removed in the next major version.
+    #[deprecated(since = "1.3.0", note = "use `shared_lib` instead")]
+    #[cfg(feature = "internals")]
+    #[cfg(not(feature = "no_function"))]
+    #[inline(always)]
+    #[must_use]
+    pub fn lib(&self) -> &crate::Module {
+        &self.functions
+    }
+}

src/custom_syntax.rs

@@ -335,7 +335,6 @@ impl Engine {
     /// * `Ok(None)`: parsing complete and there are no more symbols to match.
     /// * `Ok(Some(symbol))`: the next symbol to match, which can also be `$expr$`, `$ident$` or `$block$`.
     /// * `Err(ParseError)`: error that is reflected back to the [`Engine`], normally `ParseError(ParseErrorType::BadInput(LexError::ImproperSymbol(message)), Position::NONE)` to indicate a syntax error, but it can be any [`ParseError`].
-    ///
     pub fn register_custom_syntax_raw(
         &mut self,
         key: impl Into<Identifier>,

src/engine.rs

@@ -30,7 +30,7 @@ use std::{
 };
 
 #[cfg(not(feature = "no_index"))]
-use crate::Array;
+use crate::{Array, Blob};
 
 #[cfg(not(feature = "no_object"))]
 use crate::Map;
@@ -42,10 +42,6 @@ pub type Precedence = NonZeroU8;
 
 /// _(internals)_ A stack of imported [modules][Module] plus mutable runtime global states.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 //
 // # Implementation Notes
 //
@@ -69,7 +65,9 @@ pub struct Imports {
     pub num_operations: u64,
     /// Number of modules loaded.
     pub num_modules: usize,
-    /// Function call hashes to FN_IDX_GET and FN_IDX_SET.
+    /// Function call hashes to index getters and setters.
+    ///
+    /// Not available under `no_index` and `no_object`.
     #[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
     fn_hash_indexing: (u64, u64),
     /// Embedded module resolver.
@@ -78,19 +76,28 @@ pub struct Imports {
     #[cfg(not(feature = "no_module"))]
     pub embedded_module_resolver: Option<Shared<crate::module::resolvers::StaticModuleResolver>>,
     /// Cache of globally-defined constants.
+    ///
+    /// Not available under `no_module` and `no_function`.
     #[cfg(not(feature = "no_module"))]
     #[cfg(not(feature = "no_function"))]
     global_constants: Option<Shared<crate::Locked<BTreeMap<Identifier, Dynamic>>>>,
 }
 
+impl Default for Imports {
+    #[inline(always)]
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Imports {
     /// Create a new stack of imported [modules][Module].
     #[inline(always)]
     #[must_use]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
-            keys: StaticVec::new(),
+            keys: StaticVec::new_const(),
-            modules: StaticVec::new(),
+            modules: StaticVec::new_const(),
             source: None,
             num_operations: 0,
             num_modules: 0,
@@ -131,12 +138,17 @@ impl Imports {
     /// Get the index of an imported [module][Module] by name.
     #[inline]
     #[must_use]
-    pub fn find(&self, name: &str) -> Option<usize> {
+    pub fn find(&self, name: impl AsRef<str>) -> Option<usize> {
-        self.keys
+        let name = name.as_ref();
-            .iter()
+        let len = self.keys.len();
-            .enumerate()
+
-            .rev()
+        self.keys.iter().rev().enumerate().find_map(|(i, key)| {
-            .find_map(|(i, key)| if key == name { Some(i) } else { None })
+            if key == name {
+                Some(len - 1 - i)
+            } else {
+                None
+            }
+        })
     }
     /// Push an imported [module][Module] onto the stack.
     #[inline(always)]
@@ -156,8 +168,8 @@ impl Imports {
     pub fn iter(&self) -> impl Iterator<Item = (&str, &Module)> {
         self.keys
             .iter()
-            .zip(self.modules.iter())
             .rev()
+            .zip(self.modules.iter().rev())
             .map(|(name, module)| (name.as_str(), module.as_ref()))
     }
     /// Get an iterator to this stack of imported [modules][Module] in reverse order.
@@ -222,7 +234,7 @@ impl Imports {
     /// Set a constant into the cache of globally-defined constants.
     #[cfg(not(feature = "no_module"))]
     #[cfg(not(feature = "no_function"))]
-    pub(crate) fn set_global_constant(&mut self, name: &str, value: Dynamic) {
+    pub(crate) fn set_global_constant(&mut self, name: impl Into<Identifier>, value: Dynamic) {
         if self.global_constants.is_none() {
             let dict: crate::Locked<_> = BTreeMap::new().into();
             self.global_constants = Some(dict.into());
@@ -482,6 +494,10 @@ pub enum Target<'a> {
     /// This is necessary because directly pointing to a bit inside an [`INT`][crate::INT] is impossible.
     #[cfg(not(feature = "no_index"))]
     BitField(&'a mut Dynamic, usize, Dynamic),
+    /// The target is a byte inside a Blob.
+    /// This is necessary because directly pointing to a byte (in [`Dynamic`] form) inside a blob is impossible.
+    #[cfg(not(feature = "no_index"))]
+    BlobByte(&'a mut Dynamic, usize, Dynamic),
     /// The target is a character inside a String.
     /// This is necessary because directly pointing to a char inside a String is impossible.
     #[cfg(not(feature = "no_index"))]
@@ -500,9 +516,7 @@ impl<'a> Target<'a> {
             Self::LockGuard(_) => true,
             Self::TempValue(_) => false,
             #[cfg(not(feature = "no_index"))]
-            Self::BitField(_, _, _) => false,
+            Self::BitField(_, _, _) | Self::BlobByte(_, _, _) | Self::StringChar(_, _, _) => false,
-            #[cfg(not(feature = "no_index"))]
-            Self::StringChar(_, _, _) => false,
         }
     }
     /// Is the `Target` a temp value?
@@ -515,9 +529,7 @@ impl<'a> Target<'a> {
             Self::LockGuard(_) => false,
             Self::TempValue(_) => true,
             #[cfg(not(feature = "no_index"))]
-            Self::BitField(_, _, _) => false,
+            Self::BitField(_, _, _) | Self::BlobByte(_, _, _) | Self::StringChar(_, _, _) => false,
-            #[cfg(not(feature = "no_index"))]
-            Self::StringChar(_, _, _) => false,
         }
     }
     /// Is the `Target` a shared value?
@@ -531,9 +543,7 @@ impl<'a> Target<'a> {
             Self::LockGuard(_) => true,
             Self::TempValue(r) => r.is_shared(),
             #[cfg(not(feature = "no_index"))]
-            Self::BitField(_, _, _) => false,
+            Self::BitField(_, _, _) | Self::BlobByte(_, _, _) | Self::StringChar(_, _, _) => false,
-            #[cfg(not(feature = "no_index"))]
-            Self::StringChar(_, _, _) => false,
         }
     }
     /// Is the `Target` a specific type?
@@ -549,6 +559,8 @@ impl<'a> Target<'a> {
             #[cfg(not(feature = "no_index"))]
             Self::BitField(_, _, _) => TypeId::of::<T>() == TypeId::of::<bool>(),
             #[cfg(not(feature = "no_index"))]
+            Self::BlobByte(_, _, _) => TypeId::of::<T>() == TypeId::of::<Blob>(),
+            #[cfg(not(feature = "no_index"))]
             Self::StringChar(_, _, _) => TypeId::of::<T>() == TypeId::of::<char>(),
         }
     }
@@ -564,6 +576,8 @@ impl<'a> Target<'a> {
             #[cfg(not(feature = "no_index"))]
             Self::BitField(_, _, value) => value, // Boolean is taken
             #[cfg(not(feature = "no_index"))]
+            Self::BlobByte(_, _, value) => value, // Byte is taken
+            #[cfg(not(feature = "no_index"))]
             Self::StringChar(_, _, ch) => ch, // Character is taken
         }
     }
@@ -617,6 +631,27 @@ impl<'a> Target<'a> {
                 }
             }
             #[cfg(not(feature = "no_index"))]
+            Self::BlobByte(value, index, new_val) => {
+                // Replace the byte at the specified index position
+                let new_byte = new_val.as_int().map_err(|err| {
+                    Box::new(EvalAltResult::ErrorMismatchDataType(
+                        "INT".to_string(),
+                        err.to_string(),
+                        Position::NONE,
+                    ))
+                })?;
+
+                let value = &mut *value.write_lock::<Blob>().expect("`Blob`");
+
+                let index = *index;
+
+                if index < value.len() {
+                    value[index] = (new_byte & 0x000f) as u8;
+                } else {
+                    unreachable!("blob index out of bounds: {}", index);
+                }
+            }
+            #[cfg(not(feature = "no_index"))]
             Self::StringChar(s, index, new_val) => {
                 // Replace the character at the specified index position
                 let new_ch = new_val.as_char().map_err(|err| {
@@ -670,9 +705,9 @@ impl Deref for Target<'_> {
             Self::LockGuard((r, _)) => &**r,
             Self::TempValue(ref r) => r,
             #[cfg(not(feature = "no_index"))]
-            Self::BitField(_, _, ref r) => r,
+            Self::BitField(_, _, ref r)
-            #[cfg(not(feature = "no_index"))]
+            | Self::BlobByte(_, _, ref r)
-            Self::StringChar(_, _, ref r) => r,
+            | Self::StringChar(_, _, ref r) => r,
         }
     }
 }
@@ -693,9 +728,9 @@ impl DerefMut for Target<'_> {
             Self::LockGuard((r, _)) => r.deref_mut(),
             Self::TempValue(ref mut r) => r,
             #[cfg(not(feature = "no_index"))]
-            Self::BitField(_, _, ref mut r) => r,
+            Self::BitField(_, _, ref mut r)
-            #[cfg(not(feature = "no_index"))]
+            | Self::BlobByte(_, _, ref mut r)
-            Self::StringChar(_, _, ref mut r) => r,
+            | Self::StringChar(_, _, ref mut r) => r,
         }
     }
 }
@@ -717,10 +752,6 @@ impl<T: Into<Dynamic>> From<T> for Target<'_> {
 
 /// _(internals)_ An entry in a function resolution cache.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone)]
 pub struct FnResolutionCacheEntry {
     /// Function.
@@ -731,18 +762,10 @@ pub struct FnResolutionCacheEntry {
 
 /// _(internals)_ A function resolution cache.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 pub type FnResolutionCache = BTreeMap<u64, Option<Box<FnResolutionCacheEntry>>>;
 
 /// _(internals)_ A type that holds all the current states of the [`Engine`].
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone)]
 pub struct EvalState {
     /// Normally, access to variables are parsed with a relative offset into the [`Scope`] to avoid a lookup.
@@ -761,11 +784,11 @@ impl EvalState {
     /// Create a new [`EvalState`].
     #[inline(always)]
     #[must_use]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             always_search_scope: false,
             scope_level: 0,
-            fn_resolution_caches: StaticVec::new(),
+            fn_resolution_caches: StaticVec::new_const(),
         }
     }
     /// Is the state currently at global (root) level?
@@ -774,6 +797,12 @@ impl EvalState {
     pub const fn is_global(&self) -> bool {
         self.scope_level == 0
     }
+    /// Get the number of function resolution cache(s) in the stack.
+    #[inline(always)]
+    #[must_use]
+    pub fn fn_resolution_caches_len(&self) -> usize {
+        self.fn_resolution_caches.len()
+    }
     /// Get a mutable reference to the current function resolution cache.
     #[inline]
     #[must_use]
@@ -790,81 +819,10 @@ impl EvalState {
     pub fn push_fn_resolution_cache(&mut self) {
         self.fn_resolution_caches.push(BTreeMap::new());
     }
-    /// Remove the current function resolution cache from the stack and make the last one current.
+    /// Rewind the function resolution caches stack to a particular size.
-    ///
-    /// # Panics
-    ///
-    /// Panics if there is no more function resolution cache in the stack.
     #[inline(always)]
-    pub fn pop_fn_resolution_cache(&mut self) {
+    pub fn rewind_fn_resolution_caches(&mut self, len: usize) {
-        self.fn_resolution_caches.pop().expect("not empty");
+        self.fn_resolution_caches.truncate(len);
-    }
-}
-
-/// _(internals)_ A type containing all the limits imposed by the [`Engine`].
-/// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
-#[cfg(not(feature = "unchecked"))]
-#[derive(Debug, Clone, Eq, PartialEq, Hash)]
-pub struct Limits {
-    /// Maximum levels of call-stack to prevent infinite recursion.
-    ///
-    /// Set to zero to effectively disable function calls.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(not(feature = "no_function"))]
-    pub max_call_stack_depth: usize,
-    /// Maximum depth of statements/expressions at global level.
-    pub max_expr_depth: Option<NonZeroUsize>,
-    /// Maximum depth of statements/expressions in functions.
-    ///
-    /// Not available under `no_function`.
-    #[cfg(not(feature = "no_function"))]
-    pub max_function_expr_depth: Option<NonZeroUsize>,
-    /// Maximum number of operations allowed to run.
-    pub max_operations: Option<std::num::NonZeroU64>,
-    /// Maximum number of [modules][Module] allowed to load.
-    ///
-    /// Set to zero to effectively disable loading any [module][Module].
-    ///
-    /// Not available under `no_module`.
-    #[cfg(not(feature = "no_module"))]
-    pub max_modules: usize,
-    /// Maximum length of a [string][ImmutableString].
-    pub max_string_size: Option<NonZeroUsize>,
-    /// Maximum length of an [array][Array].
-    ///
-    /// Not available under `no_index`.
-    #[cfg(not(feature = "no_index"))]
-    pub max_array_size: Option<NonZeroUsize>,
-    /// Maximum number of properties in an [object map][Map].
-    ///
-    /// Not available under `no_object`.
-    #[cfg(not(feature = "no_object"))]
-    pub max_map_size: Option<NonZeroUsize>,
-}
-
-#[cfg(not(feature = "unchecked"))]
-impl Limits {
-    pub const fn new() -> Self {
-        Self {
-            #[cfg(not(feature = "no_function"))]
-            max_call_stack_depth: MAX_CALL_STACK_DEPTH,
-            max_expr_depth: NonZeroUsize::new(MAX_EXPR_DEPTH),
-            #[cfg(not(feature = "no_function"))]
-            max_function_expr_depth: NonZeroUsize::new(MAX_FUNCTION_EXPR_DEPTH),
-            max_operations: None,
-            #[cfg(not(feature = "no_module"))]
-            max_modules: usize::MAX,
-            max_string_size: None,
-            #[cfg(not(feature = "no_index"))]
-            max_array_size: None,
-            #[cfg(not(feature = "no_object"))]
-            max_map_size: None,
-        }
     }
 }
 
@@ -1011,13 +969,16 @@ pub struct Engine {
     #[cfg(not(feature = "unchecked"))]
     pub(crate) progress: Option<crate::func::native::OnProgressCallback>,
 
-    /// Optimize the AST after compilation.
+    /// Optimize the [`AST`][crate::AST] after compilation.
     #[cfg(not(feature = "no_optimize"))]
     pub(crate) optimization_level: crate::OptimizationLevel,
 
+    /// Language options.
+    pub(crate) options: crate::api::options::LanguageOptions,
+
     /// Max limits.
     #[cfg(not(feature = "unchecked"))]
-    pub(crate) limits: Limits,
+    pub(crate) limits: crate::api::limits::Limits,
 }
 
 impl fmt::Debug for Engine {
@@ -1038,24 +999,24 @@ impl Default for Engine {
 #[cfg(not(feature = "no_object"))]
 #[inline]
 #[must_use]
-pub fn make_getter(id: &str) -> String {
+pub fn make_getter(id: impl AsRef<str>) -> String {
-    format!("{}{}", FN_GET, id)
+    format!("{}{}", FN_GET, id.as_ref())
 }
 
 /// Make setter function
 #[cfg(not(feature = "no_object"))]
 #[inline]
 #[must_use]
-pub fn make_setter(id: &str) -> String {
+pub fn make_setter(id: impl AsRef<str>) -> String {
-    format!("{}{}", FN_SET, id)
+    format!("{}{}", FN_SET, id.as_ref())
 }
 
 /// Is this function an anonymous function?
 #[cfg(not(feature = "no_function"))]
 #[inline(always)]
 #[must_use]
-pub fn is_anonymous_fn(fn_name: &str) -> bool {
+pub fn is_anonymous_fn(fn_name: impl AsRef<str>) -> bool {
-    fn_name.starts_with(FN_ANONYMOUS)
+    fn_name.as_ref().starts_with(FN_ANONYMOUS)
 }
 
 /// Print to `stdout`
@@ -1114,7 +1075,7 @@ impl Engine {
     #[must_use]
     pub fn new_raw() -> Self {
         let mut engine = Self {
-            global_modules: StaticVec::new(),
+            global_modules: StaticVec::new_const(),
             global_sub_modules: BTreeMap::new(),
 
             #[cfg(not(feature = "no_module"))]
@@ -1136,10 +1097,12 @@ impl Engine {
             progress: None,
 
             #[cfg(not(feature = "no_optimize"))]
-            optimization_level: Default::default(),
+            optimization_level: crate::OptimizationLevel::default(),
+
+            options: crate::api::options::LanguageOptions::new(),
 
             #[cfg(not(feature = "unchecked"))]
-            limits: Limits::new(),
+            limits: crate::api::limits::Limits::new(),
         };
 
         // Add the global namespace module
@@ -1822,7 +1785,7 @@ impl Engine {
             _ => unreachable!("index or dot chain expected, but gets {:?}", expr),
         };
 
-        let idx_values = &mut StaticVec::new();
+        let idx_values = &mut StaticVec::new_const();
 
         self.eval_dot_index_chain_arguments(
             scope, mods, state, lib, this_ptr, rhs, term, chain_type, idx_values, 0, level,
@@ -2059,6 +2022,50 @@ impl Engine {
                     .ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos).into())
             }
 
+            #[cfg(not(feature = "no_index"))]
+            Dynamic(Union::Blob(arr, _, _)) => {
+                // val_blob[idx]
+                let index = idx
+                    .as_int()
+                    .map_err(|typ| self.make_type_mismatch_err::<crate::INT>(typ, idx_pos))?;
+
+                let arr_len = arr.len();
+
+                #[cfg(not(feature = "unchecked"))]
+                let arr_idx = if index < 0 {
+                    // Count from end if negative
+                    arr_len
+                        - index
+                            .checked_abs()
+                            .ok_or_else(|| EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos))
+                            .and_then(|n| {
+                                if n as usize > arr_len {
+                                    Err(EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos)
+                                        .into())
+                                } else {
+                                    Ok(n as usize)
+                                }
+                            })?
+                } else {
+                    index as usize
+                };
+                #[cfg(feature = "unchecked")]
+                let arr_idx = if index < 0 {
+                    // Count from end if negative
+                    arr_len - index.abs() as usize
+                } else {
+                    index as usize
+                };
+
+                let value = arr
+                    .get(arr_idx)
+                    .map(|&v| (v as INT).into())
+                    .ok_or_else(|| {
+                        Box::new(EvalAltResult::ErrorArrayBounds(arr_len, index, idx_pos))
+                    })?;
+                Ok(Target::BlobByte(target, arr_idx, value))
+            }
+
             #[cfg(not(feature = "no_object"))]
             Dynamic(Union::Map(map, _, _)) => {
                 // val_map[idx]
@@ -2382,7 +2389,7 @@ impl Engine {
         lib: &[&Module],
         this_ptr: &mut Option<&mut Dynamic>,
         statements: &[Stmt],
-        restore_prev_state: bool,
+        restore_orig_state: bool,
         rewind_scope: bool,
         level: usize,
     ) -> RhaiResult {
@@ -2390,10 +2397,10 @@ impl Engine {
             return Ok(Dynamic::UNIT);
         }
 
-        let mut _extra_fn_resolution_cache = false;
+        let orig_always_search_scope = state.always_search_scope;
-        let prev_always_search_scope = state.always_search_scope;
+        let orig_scope_len = scope.len();
-        let prev_scope_len = scope.len();
+        let orig_mods_len = mods.len();
-        let prev_mods_len = mods.len();
+        let orig_fn_resolution_caches_len = state.fn_resolution_caches_len();
 
         if rewind_scope {
             state.scope_level += 1;
@@ -2413,15 +2420,14 @@ impl Engine {
                     .skip(_mods_len)
                     .any(|(_, m)| m.contains_indexed_global_functions())
                 {
-                    if _extra_fn_resolution_cache {
+                    if state.fn_resolution_caches_len() > orig_fn_resolution_caches_len {
                         // When new module is imported with global functions and there is already
                         // a new cache, clear it - notice that this is expensive as all function
                         // resolutions must start again
                         state.fn_resolution_cache_mut().clear();
-                    } else if restore_prev_state {
+                    } else if restore_orig_state {
                         // When new module is imported with global functions, push a new cache
                         state.push_fn_resolution_cache();
-                        _extra_fn_resolution_cache = true;
                     } else {
                         // When the block is to be evaluated in-place, just clear the current cache
                         state.fn_resolution_cache_mut().clear();
@@ -2432,21 +2438,19 @@ impl Engine {
             Ok(r)
         });
 
-        if _extra_fn_resolution_cache {
+        // If imports list is modified, pop the functions lookup cache
-            // If imports list is modified, pop the functions lookup cache
+        state.rewind_fn_resolution_caches(orig_fn_resolution_caches_len);
-            state.pop_fn_resolution_cache();
-        }
 
         if rewind_scope {
-            scope.rewind(prev_scope_len);
+            scope.rewind(orig_scope_len);
             state.scope_level -= 1;
         }
-        if restore_prev_state {
+        if restore_orig_state {
-            mods.truncate(prev_mods_len);
+            mods.truncate(orig_mods_len);
 
             // The impact of new local variables goes away at the end of a block
             // because any new variables introduced will go out of scope
-            state.always_search_scope = prev_always_search_scope;
+            state.always_search_scope = orig_always_search_scope;
         }
 
         result
@@ -3044,7 +3048,7 @@ impl Engine {
                     #[cfg(not(feature = "no_function"))]
                     #[cfg(not(feature = "no_module"))]
                     if entry_type == AccessMode::ReadOnly && lib.iter().any(|&m| !m.is_empty()) {
-                        mods.set_global_constant(name, value.clone());
+                        mods.set_global_constant(name.clone(), value.clone());
                     }
 
                     (
@@ -3203,6 +3207,7 @@ impl Engine {
                                 let (a, m, s) = calc_size(value);
                                 (arrays + a + 1, maps + m, strings + s)
                             }
+                            Union::Blob(ref a, _, _) => (arrays + 1 + a.len(), maps, strings),
                             #[cfg(not(feature = "no_object"))]
                             Union::Map(_, _, _) => {
                                 let (a, m, s) = calc_size(value);
@@ -3212,6 +3217,8 @@ impl Engine {
                             _ => (arrays + 1, maps, strings),
                         })
                 }
+                #[cfg(not(feature = "no_index"))]
+                Union::Blob(ref arr, _, _) => (arr.len(), 0, 0),
                 #[cfg(not(feature = "no_object"))]
                 Union::Map(ref map, _, _) => {
                     map.values()
@@ -3221,6 +3228,8 @@ impl Engine {
                                 let (a, m, s) = calc_size(value);
                                 (arrays + a, maps + m + 1, strings + s)
                             }
+                            #[cfg(not(feature = "no_index"))]
+                            Union::Blob(ref a, _, _) => (arrays + a.len(), maps, strings),
                             Union::Map(_, _, _) => {
                                 let (a, m, s) = calc_size(value);
                                 (arrays + a, maps + m + 1, strings + s)

src/func/args.rs

@@ -1,6 +1,5 @@
 //! Helper module which defines [`FuncArgs`] to make function calling easier.
 
-#![cfg(not(feature = "no_function"))]
 #![allow(non_snake_case)]
 
 use crate::types::dynamic::Variant;
@@ -35,6 +34,8 @@ pub trait FuncArgs {
     /// }
     ///
     /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_function"))]
+    /// # {
     /// let options = Options { foo: false, bar: "world".to_string(), baz: 42 };
     ///
     /// let engine = Engine::new();
@@ -50,6 +51,7 @@ pub trait FuncArgs {
     /// let result: String = engine.call_fn(&mut scope, &ast, "hello", options)?;
     ///
     /// assert_eq!(result, "world42");
+    /// # }
     /// # Ok(())
     /// # }
     /// ```

src/func/builtin.rs

@@ -10,6 +10,10 @@ use std::prelude::v1::*;
 #[cfg(not(feature = "no_float"))]
 use crate::FLOAT;
 
+#[cfg(not(feature = "no_float"))]
+#[cfg(feature = "no_std")]
+use num_traits::Float;
+
 #[cfg(feature = "decimal")]
 use rust_decimal::Decimal;
 
@@ -48,10 +52,6 @@ pub fn get_builtin_binary_op_fn(
     x: &Dynamic,
     y: &Dynamic,
 ) -> Option<fn(NativeCallContext, &mut FnCallArgs) -> RhaiResult> {
-    #[cfg(feature = "no_std")]
-    #[cfg(not(feature = "no_float"))]
-    use num_traits::Float;
-
     let type1 = x.type_id();
     let type2 = y.type_id();
 
@@ -127,9 +127,9 @@ pub fn get_builtin_binary_op_fn(
         } };
     }
 
+    #[cfg(not(feature = "no_float"))]
     macro_rules! impl_float {
         ($x:ty, $xx:ident, $y:ty, $yy:ident) => {
-            #[cfg(not(feature = "no_float"))]
             if types_pair == (TypeId::of::<$x>(), TypeId::of::<$y>()) {
                 return match op {
                     "+" => Some(impl_op!(FLOAT => $xx + $yy)),
@@ -150,13 +150,16 @@ pub fn get_builtin_binary_op_fn(
         };
     }
 
-    impl_float!(FLOAT, as_float, FLOAT, as_float);
+    #[cfg(not(feature = "no_float"))]
-    impl_float!(FLOAT, as_float, INT, as_int);
+    {
-    impl_float!(INT, as_int, FLOAT, as_float);
+        impl_float!(FLOAT, as_float, FLOAT, as_float);
+        impl_float!(FLOAT, as_float, INT, as_int);
+        impl_float!(INT, as_int, FLOAT, as_float);
+    }
 
+    #[cfg(feature = "decimal")]
     macro_rules! impl_decimal {
         ($x:ty, $xx:ident, $y:ty, $yy:ident) => {
-            #[cfg(feature = "decimal")]
             if types_pair == (TypeId::of::<$x>(), TypeId::of::<$y>()) {
                 #[cfg(not(feature = "unchecked"))]
                 use crate::packages::arithmetic::decimal_functions::*;
@@ -199,9 +202,12 @@ pub fn get_builtin_binary_op_fn(
         };
     }
 
-    impl_decimal!(Decimal, as_decimal, Decimal, as_decimal);
+    #[cfg(feature = "decimal")]
-    impl_decimal!(Decimal, as_decimal, INT, as_int);
+    {
-    impl_decimal!(INT, as_int, Decimal, as_decimal);
+        impl_decimal!(Decimal, as_decimal, Decimal, as_decimal);
+        impl_decimal!(Decimal, as_decimal, INT, as_int);
+        impl_decimal!(INT, as_int, Decimal, as_decimal);
+    }
 
     // char op string
     if types_pair == (TypeId::of::<char>(), TypeId::of::<ImmutableString>()) {
@@ -419,10 +425,6 @@ pub fn get_builtin_op_assignment_fn(
     x: &Dynamic,
     y: &Dynamic,
 ) -> Option<fn(NativeCallContext, &mut FnCallArgs) -> RhaiResult> {
-    #[cfg(feature = "no_std")]
-    #[cfg(not(feature = "no_float"))]
-    use num_traits::Float;
-
     let type1 = x.type_id();
     let type2 = y.type_id();
 
@@ -468,9 +470,9 @@ pub fn get_builtin_op_assignment_fn(
         } };
     }
 
+    #[cfg(not(feature = "no_float"))]
     macro_rules! impl_float {
         ($x:ident, $xx:ident, $y:ty, $yy:ident) => {
-            #[cfg(not(feature = "no_float"))]
             if types_pair == (TypeId::of::<$x>(), TypeId::of::<$y>()) {
                 return match op {
                     "+=" => Some(impl_op!($x += $yy)),
@@ -485,12 +487,15 @@ pub fn get_builtin_op_assignment_fn(
         }
     }
 
-    impl_float!(FLOAT, as_float, FLOAT, as_float);
+    #[cfg(not(feature = "no_float"))]
-    impl_float!(FLOAT, as_float, INT, as_int);
+    {
+        impl_float!(FLOAT, as_float, FLOAT, as_float);
+        impl_float!(FLOAT, as_float, INT, as_int);
+    }
 
+    #[cfg(feature = "decimal")]
     macro_rules! impl_decimal {
         ($x:ident, $xx:ident, $y:ty, $yy:ident) => {
-            #[cfg(feature = "decimal")]
             if types_pair == (TypeId::of::<$x>(), TypeId::of::<$y>()) {
                 #[cfg(not(feature = "unchecked"))]
                 use crate::packages::arithmetic::decimal_functions::*;
@@ -523,8 +528,11 @@ pub fn get_builtin_op_assignment_fn(
         };
     }
 
-    impl_decimal!(Decimal, as_decimal, Decimal, as_decimal);
+    #[cfg(feature = "decimal")]
-    impl_decimal!(Decimal, as_decimal, INT, as_int);
+    {
+        impl_decimal!(Decimal, as_decimal, Decimal, as_decimal);
+        impl_decimal!(Decimal, as_decimal, INT, as_int);
+    }
 
     // string op= char
     if types_pair == (TypeId::of::<ImmutableString>(), TypeId::of::<char>()) {

src/func/call.rs

@@ -13,7 +13,7 @@ use crate::tokenizer::Token;
 use crate::{
     ast::{Expr, Stmt},
     calc_fn_hash, calc_fn_params_hash, combine_hashes, Dynamic, Engine, EvalAltResult, FnPtr,
-    Identifier, ImmutableString, Module, ParseErrorType, Position, RhaiResult, Scope, StaticVec,
+    Identifier, ImmutableString, Module, Position, RhaiResult, Scope, StaticVec,
 };
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
@@ -107,7 +107,7 @@ impl Drop for ArgBackup<'_> {
 #[cfg(not(feature = "no_closure"))]
 #[inline]
 pub fn ensure_no_data_race(
-    fn_name: &str,
+    fn_name: impl AsRef<str>,
     args: &FnCallArgs,
     is_method_call: bool,
 ) -> Result<(), Box<EvalAltResult>> {
@@ -118,7 +118,7 @@ pub fn ensure_no_data_race(
         .find(|(_, a)| a.is_locked())
     {
         return Err(EvalAltResult::ErrorDataRace(
-            format!("argument #{} of function '{}'", n + 1, fn_name),
+            format!("argument #{} of function '{}'", n + 1, fn_name.as_ref()),
             Position::NONE,
         )
         .into());
@@ -134,7 +134,7 @@ impl Engine {
     fn gen_call_signature(
         &self,
         namespace: Option<&NamespaceRef>,
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         args: &[&mut Dynamic],
     ) -> String {
         format!(
@@ -145,7 +145,7 @@ impl Engine {
             } else {
                 ""
             },
-            fn_name,
+            fn_name.as_ref(),
             args.iter()
                 .map(|a| if a.is::<ImmutableString>() {
                     "&str | ImmutableString | String"
@@ -171,12 +171,14 @@ impl Engine {
         mods: &Imports,
         state: &'s mut EvalState,
         lib: &[&Module],
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         hash_script: u64,
         args: Option<&mut FnCallArgs>,
         allow_dynamic: bool,
         is_op_assignment: bool,
     ) -> Option<&'s FnResolutionCacheEntry> {
+        let fn_name = fn_name.as_ref();
+
         let mut hash = args.as_ref().map_or(hash_script, |args| {
             combine_hashes(
                 hash_script,
@@ -301,22 +303,24 @@ impl Engine {
     ///
     /// Function call arguments be _consumed_ when the function requires them to be passed by value.
     /// All function arguments not in the first position are always passed by value and thus consumed.
+    ///
     /// **DO NOT** reuse the argument values unless for the first `&mut` argument - all others are silently replaced by `()`!
     pub(crate) fn call_native_fn(
         &self,
         mods: &mut Imports,
         state: &mut EvalState,
         lib: &[&Module],
-        name: &str,
+        name: impl AsRef<str>,
         hash: u64,
         args: &mut FnCallArgs,
-        is_method_call: bool,
+        is_ref_mut: bool,
         is_op_assign: bool,
         pos: Position,
     ) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
         #[cfg(not(feature = "unchecked"))]
         self.inc_operations(&mut mods.num_operations, pos)?;
 
+        let name = name.as_ref();
         let parent_source = mods.source.clone();
 
         // Check if function access already in the cache
@@ -327,7 +331,8 @@ impl Engine {
 
             // Calling pure function but the first argument is a reference?
             let mut backup: Option<ArgBackup> = None;
-            if is_method_call && func.is_pure() && !args.is_empty() {
+            if is_ref_mut && func.is_pure() && !args.is_empty() {
+                // Clone the first argument
                 backup = Some(ArgBackup::new());
                 backup
                     .as_mut()
@@ -393,6 +398,8 @@ impl Engine {
             });
         }
 
+        // Error handling
+
         match name {
             // index getter function not found?
             #[cfg(any(not(feature = "no_index"), not(feature = "no_object")))]
@@ -469,202 +476,20 @@ impl Engine {
         }
     }
 
-    /// Call a script-defined function.
-    ///
-    /// If `rewind_scope` is `false`, arguments are removed from the scope but new variables are not.
-    ///
-    /// # WARNING
-    ///
-    /// Function call arguments may be _consumed_ when the function requires them to be passed by value.
-    /// All function arguments not in the first position are always passed by value and thus consumed.
-    /// **DO NOT** reuse the argument values unless for the first `&mut` argument - all others are silently replaced by `()`!
-    #[cfg(not(feature = "no_function"))]
-    pub(crate) fn call_script_fn(
-        &self,
-        scope: &mut Scope,
-        mods: &mut Imports,
-        state: &mut EvalState,
-        lib: &[&Module],
-        this_ptr: &mut Option<&mut Dynamic>,
-        fn_def: &crate::ast::ScriptFnDef,
-        args: &mut FnCallArgs,
-        pos: Position,
-        rewind_scope: bool,
-        level: usize,
-    ) -> RhaiResult {
-        #[inline(never)]
-        fn make_error(
-            name: String,
-            fn_def: &crate::ast::ScriptFnDef,
-            mods: &Imports,
-            err: Box<EvalAltResult>,
-            pos: Position,
-        ) -> RhaiResult {
-            Err(EvalAltResult::ErrorInFunctionCall(
-                name,
-                fn_def
-                    .lib
-                    .as_ref()
-                    .and_then(|m| m.id().map(|id| id.to_string()))
-                    .or_else(|| mods.source.as_ref().map(|s| s.to_string()))
-                    .unwrap_or_default(),
-                err,
-                pos,
-            )
-            .into())
-        }
-
-        assert!(fn_def.params.len() == args.len());
-
-        #[cfg(not(feature = "unchecked"))]
-        self.inc_operations(&mut mods.num_operations, pos)?;
-
-        if fn_def.body.is_empty() {
-            return Ok(Dynamic::UNIT);
-        }
-
-        // Check for stack overflow
-        #[cfg(not(feature = "no_function"))]
-        #[cfg(not(feature = "unchecked"))]
-        if level > self.max_call_levels() {
-            return Err(EvalAltResult::ErrorStackOverflow(pos).into());
-        }
-
-        let prev_scope_len = scope.len();
-        let prev_mods_len = mods.len();
-
-        // Put arguments into scope as variables
-        // Actually consume the arguments instead of cloning them
-        scope.extend(
-            fn_def
-                .params
-                .iter()
-                .zip(args.iter_mut().map(|v| mem::take(*v)))
-                .map(|(name, value)| {
-                    let var_name: std::borrow::Cow<'_, str> =
-                        crate::r#unsafe::unsafe_cast_var_name_to_lifetime(name).into();
-                    (var_name, value)
-                }),
-        );
-
-        // Merge in encapsulated environment, if any
-        let mut lib_merged = StaticVec::with_capacity(lib.len() + 1);
-
-        let (unified, is_unified) = if let Some(ref env_lib) = fn_def.lib {
-            state.push_fn_resolution_cache();
-            lib_merged.push(env_lib.as_ref());
-            lib_merged.extend(lib.iter().cloned());
-            (lib_merged.as_ref(), true)
-        } else {
-            (lib, false)
-        };
-
-        #[cfg(not(feature = "no_module"))]
-        if !fn_def.mods.is_empty() {
-            fn_def
-                .mods
-                .iter_raw()
-                .for_each(|(n, m)| mods.push(n.clone(), m.clone()));
-        }
-
-        // Evaluate the function
-        let body = &fn_def.body;
-        let result = self
-            .eval_stmt_block(
-                scope,
-                mods,
-                state,
-                unified,
-                this_ptr,
-                body,
-                true,
-                rewind_scope,
-                level,
-            )
-            .or_else(|err| match *err {
-                // Convert return statement to return value
-                EvalAltResult::Return(x, _) => Ok(x),
-                // Error in sub function call
-                EvalAltResult::ErrorInFunctionCall(name, src, err, _) => {
-                    let fn_name = if src.is_empty() {
-                        format!("{} < {}", name, fn_def.name)
-                    } else {
-                        format!("{} @ '{}' < {}", name, src, fn_def.name)
-                    };
-
-                    make_error(fn_name, fn_def, mods, err, pos)
-                }
-                // System errors are passed straight-through
-                mut err if err.is_system_exception() => {
-                    err.set_position(pos);
-                    Err(err.into())
-                }
-                // Other errors are wrapped in `ErrorInFunctionCall`
-                _ => make_error(fn_def.name.to_string(), fn_def, mods, err, pos),
-            });
-
-        // Remove all local variables
-        if rewind_scope {
-            scope.rewind(prev_scope_len);
-        } else if !args.is_empty() {
-            // Remove arguments only, leaving new variables in the scope
-            scope.remove_range(prev_scope_len, args.len())
-        }
-
-        mods.truncate(prev_mods_len);
-
-        if is_unified {
-            state.pop_fn_resolution_cache();
-        }
-
-        result
-    }
-
-    // Does a scripted function exist?
-    #[cfg(not(feature = "no_function"))]
-    #[must_use]
-    pub(crate) fn has_script_fn(
-        &self,
-        mods: Option<&Imports>,
-        state: &mut EvalState,
-        lib: &[&Module],
-        hash_script: u64,
-    ) -> bool {
-        let cache = state.fn_resolution_cache_mut();
-
-        if let Some(result) = cache.get(&hash_script).map(|v| v.is_some()) {
-            return result;
-        }
-
-        // First check script-defined functions
-        let result = lib.iter().any(|&m| m.contains_fn(hash_script))
-            // Then check the global namespace and packages
-            || self.global_modules.iter().any(|m| m.contains_fn(hash_script))
-            // Then check imported modules
-            || mods.map_or(false, |m| m.contains_fn(hash_script))
-            // Then check sub-modules
-            || self.global_sub_modules.values().any(|m| m.contains_qualified_fn(hash_script));
-
-        if !result {
-            cache.insert(hash_script, None);
-        }
-
-        result
-    }
-
     /// Perform an actual function call, native Rust or scripted, taking care of special functions.
     ///
     /// # WARNING
     ///
     /// Function call arguments may be _consumed_ when the function requires them to be passed by value.
     /// All function arguments not in the first position are always passed by value and thus consumed.
+    ///
     /// **DO NOT** reuse the argument values unless for the first `&mut` argument - all others are silently replaced by `()`!
     pub(crate) fn exec_fn_call(
         &self,
         mods: &mut Imports,
         state: &mut EvalState,
         lib: &[&Module],
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         hashes: FnCallHashes,
         args: &mut FnCallArgs,
         is_ref_mut: bool,
@@ -678,6 +503,8 @@ impl Engine {
             Err(EvalAltResult::ErrorRuntime(msg.into(), pos).into())
         }
 
+        let fn_name = fn_name.as_ref();
+
         // Check for data race.
         #[cfg(not(feature = "no_closure"))]
         ensure_no_data_race(fn_name, args, is_ref_mut)?;
@@ -857,14 +684,14 @@ impl Engine {
         scope: &mut Scope,
         mods: &mut Imports,
         lib: &[&Module],
-        script: &str,
+        script: impl AsRef<str>,
         _pos: Position,
         level: usize,
     ) -> RhaiResult {
         #[cfg(not(feature = "unchecked"))]
         self.inc_operations(&mut mods.num_operations, _pos)?;
 
-        let script = script.trim();
+        let script = script.as_ref().trim();
         if script.is_empty() {
             return Ok(Dynamic::UNIT);
         }
@@ -879,8 +706,9 @@ impl Engine {
         )?;
 
         // If new functions are defined within the eval string, it is an error
-        if ast.lib().count().0 != 0 {
+        #[cfg(not(feature = "no_function"))]
-            return Err(ParseErrorType::WrongFnDefinition.into());
+        if !ast.shared_lib().is_empty() {
+            return Err(crate::ParseErrorType::WrongFnDefinition.into());
         }
 
         let statements = ast.statements();
@@ -899,13 +727,14 @@ impl Engine {
         mods: &mut Imports,
         state: &mut EvalState,
         lib: &[&Module],
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         mut hash: FnCallHashes,
         target: &mut crate::engine::Target,
         (call_args, call_arg_pos): &mut (StaticVec<Dynamic>, Position),
         pos: Position,
         level: usize,
     ) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
+        let fn_name = fn_name.as_ref();
         let is_ref_mut = target.is_ref();
 
         let (result, updated) = match fn_name {
@@ -1081,7 +910,7 @@ impl Engine {
         state: &mut EvalState,
         lib: &[&Module],
         this_ptr: &mut Option<&mut Dynamic>,
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         args_expr: &[Expr],
         constants: &[Dynamic],
         hashes: FnCallHashes,
@@ -1089,9 +918,10 @@ impl Engine {
         capture_scope: bool,
         level: usize,
     ) -> RhaiResult {
+        let fn_name = fn_name.as_ref();
         let mut a_expr = args_expr;
         let mut total_args = a_expr.len();
-        let mut curry = StaticVec::new();
+        let mut curry = StaticVec::new_const();
         let mut name = fn_name;
         let mut hashes = hashes;
         let redirected; // Handle call() - Redirect function call
@@ -1225,7 +1055,7 @@ impl Engine {
             // Handle eval()
             KEYWORD_EVAL if total_args == 1 => {
                 // eval - only in function call style
-                let prev_len = scope.len();
+                let orig_scope_len = scope.len();
                 let (value, pos) = self.get_arg_value(
                     scope, mods, state, lib, this_ptr, level, &a_expr[0], constants,
                 )?;
@@ -1237,7 +1067,7 @@ impl Engine {
 
                 // IMPORTANT! If the eval defines new variables in the current scope,
                 //            all variable offsets from this point on will be mis-aligned.
-                if scope.len() != prev_len {
+                if scope.len() != orig_scope_len {
                     state.always_search_scope = true;
                 }
 
@@ -1352,13 +1182,14 @@ impl Engine {
         lib: &[&Module],
         this_ptr: &mut Option<&mut Dynamic>,
         namespace: &NamespaceRef,
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         args_expr: &[Expr],
         constants: &[Dynamic],
         hash: u64,
         pos: Position,
         level: usize,
     ) -> RhaiResult {
+        let fn_name = fn_name.as_ref();
         let mut arg_values = StaticVec::with_capacity(args_expr.len());
         let mut args = StaticVec::with_capacity(args_expr.len());
         let mut first_arg_value = None;

src/func/hashing.rs

@@ -49,7 +49,7 @@ impl BuildHasher for StraightHasherBuilder {
 #[inline(always)]
 #[must_use]
 pub fn get_hasher() -> ahash::AHasher {
-    Default::default()
+    ahash::AHasher::default()
 }
 
 /// Calculate a [`u64`] hash key from a namespace-qualified variable name.
@@ -62,7 +62,10 @@ pub fn get_hasher() -> ahash::AHasher {
 /// The first module name is skipped.  Hashing starts from the _second_ module in the chain.
 #[inline]
 #[must_use]
-pub fn calc_qualified_var_hash<'a>(modules: impl Iterator<Item = &'a str>, var_name: &str) -> u64 {
+pub fn calc_qualified_var_hash<'a>(
+    modules: impl Iterator<Item = impl AsRef<str> + 'a>,
+    var_name: impl AsRef<str>,
+) -> u64 {
     let s = &mut get_hasher();
 
     // We always skip the first module
@@ -70,9 +73,9 @@ pub fn calc_qualified_var_hash<'a>(modules: impl Iterator<Item = &'a str>, var_n
     modules
         .inspect(|_| len += 1)
         .skip(1)
-        .for_each(|m| m.hash(s));
+        .for_each(|m| m.as_ref().hash(s));
     len.hash(s);
-    var_name.hash(s);
+    var_name.as_ref().hash(s);
     s.finish()
 }
 
@@ -87,9 +90,9 @@ pub fn calc_qualified_var_hash<'a>(modules: impl Iterator<Item = &'a str>, var_n
 /// The first module name is skipped.  Hashing starts from the _second_ module in the chain.
 #[inline]
 #[must_use]
-pub fn calc_qualified_fn_hash<'a>(
+pub fn calc_qualified_fn_hash(
-    modules: impl Iterator<Item = &'a str>,
+    modules: impl Iterator<Item = impl AsRef<str>>,
-    fn_name: &str,
+    fn_name: impl AsRef<str>,
     num: usize,
 ) -> u64 {
     let s = &mut get_hasher();
@@ -99,9 +102,9 @@ pub fn calc_qualified_fn_hash<'a>(
     modules
         .inspect(|_| len += 1)
         .skip(1)
-        .for_each(|m| m.hash(s));
+        .for_each(|m| m.as_ref().hash(s));
     len.hash(s);
-    fn_name.hash(s);
+    fn_name.as_ref().hash(s);
     num.hash(s);
     s.finish()
 }
@@ -112,8 +115,8 @@ pub fn calc_qualified_fn_hash<'a>(
 /// Parameter types are passed in via [`TypeId`] values from an iterator.
 #[inline(always)]
 #[must_use]
-pub fn calc_fn_hash(fn_name: &str, num: usize) -> u64 {
+pub fn calc_fn_hash(fn_name: impl AsRef<str>, num: usize) -> u64 {
-    calc_qualified_fn_hash(empty(), fn_name, num)
+    calc_qualified_fn_hash(empty::<&str>(), fn_name, num)
 }
 
 /// Calculate a [`u64`] hash key from a list of parameter types.

src/func/mod.rs

@@ -1,17 +1,15 @@
 //! Module defining mechanisms to handle function calls in Rhai.
 
-#[cfg(not(feature = "no_function"))]
 pub mod args;
 pub mod builtin;
 pub mod call;
-#[cfg(not(feature = "no_function"))]
 pub mod func;
 pub mod hashing;
 pub mod native;
 pub mod plugin;
 pub mod register;
+pub mod script;
 
-#[cfg(not(feature = "no_function"))]
 pub use args::FuncArgs;
 pub use builtin::{get_builtin_binary_op_fn, get_builtin_op_assignment_fn};
 pub use call::FnCallArgs;

src/func/native.rs

@@ -64,11 +64,11 @@ pub struct NativeCallContext<'a> {
     pos: Position,
 }
 
-impl<'a, M: AsRef<[&'a Module]> + ?Sized>
+impl<'a, M: AsRef<[&'a Module]> + ?Sized, S: AsRef<str> + 'a + ?Sized>
     From<(
         &'a Engine,
-        &'a str,
+        &'a S,
-        Option<&'a str>,
+        Option<&'a S>,
         &'a Imports,
         &'a M,
         Position,
@@ -78,8 +78,8 @@ impl<'a, M: AsRef<[&'a Module]> + ?Sized>
     fn from(
         value: (
             &'a Engine,
-            &'a str,
+            &'a S,
-            Option<&'a str>,
+            Option<&'a S>,
             &'a Imports,
             &'a M,
             Position,
@@ -87,8 +87,8 @@ impl<'a, M: AsRef<[&'a Module]> + ?Sized>
     ) -> Self {
         Self {
             engine: value.0,
-            fn_name: value.1,
+            fn_name: value.1.as_ref(),
-            source: value.2,
+            source: value.2.map(|v| v.as_ref()),
             mods: Some(value.3),
             lib: value.4.as_ref(),
             pos: value.5,
@@ -96,14 +96,14 @@ impl<'a, M: AsRef<[&'a Module]> + ?Sized>
     }
 }
 
-impl<'a, M: AsRef<[&'a Module]> + ?Sized> From<(&'a Engine, &'a str, &'a M)>
+impl<'a, M: AsRef<[&'a Module]> + ?Sized, S: AsRef<str> + 'a + ?Sized>
-    for NativeCallContext<'a>
+    From<(&'a Engine, &'a S, &'a M)> for NativeCallContext<'a>
 {
     #[inline(always)]
-    fn from(value: (&'a Engine, &'a str, &'a M)) -> Self {
+    fn from(value: (&'a Engine, &'a S, &'a M)) -> Self {
         Self {
             engine: value.0,
-            fn_name: value.1,
+            fn_name: value.1.as_ref(),
             source: None,
             mods: None,
             lib: value.2.as_ref(),
@@ -113,13 +113,22 @@ impl<'a, M: AsRef<[&'a Module]> + ?Sized> From<(&'a Engine, &'a str, &'a M)>
 }
 
 impl<'a> NativeCallContext<'a> {
-    /// Create a new [`NativeCallContext`].
+    /// _(internals)_ Create a new [`NativeCallContext`].
+    /// Exported under the `metadata` feature only.
+    #[deprecated(
+        since = "1.3.0",
+        note = "`NativeCallContext::new` will be moved under `internals`. Use `FnPtr::call` to call a function pointer directly."
+    )]
     #[inline(always)]
     #[must_use]
-    pub const fn new(engine: &'a Engine, fn_name: &'a str, lib: &'a [&Module]) -> Self {
+    pub fn new(
+        engine: &'a Engine,
+        fn_name: &'a (impl AsRef<str> + 'a + ?Sized),
+        lib: &'a [&Module],
+    ) -> Self {
         Self {
             engine,
-            fn_name,
+            fn_name: fn_name.as_ref(),
             source: None,
             mods: None,
             lib,
@@ -134,18 +143,18 @@ impl<'a> NativeCallContext<'a> {
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
     #[must_use]
-    pub const fn new_with_all_fields(
+    pub fn new_with_all_fields(
         engine: &'a Engine,
-        fn_name: &'a str,
+        fn_name: &'a (impl AsRef<str> + 'a + ?Sized),
-        source: Option<&'a str>,
+        source: Option<&'a (impl AsRef<str> + 'a + ?Sized)>,
         imports: &'a Imports,
         lib: &'a [&Module],
         pos: Position,
     ) -> Self {
         Self {
             engine,
-            fn_name,
+            fn_name: fn_name.as_ref(),
-            source,
+            source: source.map(|v| v.as_ref()),
             mods: Some(imports),
             lib,
             pos,
@@ -218,26 +227,32 @@ impl<'a> NativeCallContext<'a> {
     }
     /// Call a function inside the call context.
     ///
-    /// If `is_method_call` is [`true`], the first argument is assumed to be the
+    /// If `is_method_call` is [`true`], the first argument is assumed to be the `this` pointer for
-    /// `this` pointer for a script-defined function (or the object of a method call).
+    /// a script-defined function (or the object of a method call).
     ///
-    /// # WARNING
+    /// # WARNING - Low Level API
     ///
-    /// All arguments may be _consumed_, meaning that they may be replaced by `()`.
+    /// This function is very low level.
-    /// This is to avoid unnecessarily cloning the arguments.
     ///
-    /// Do not use the arguments after this call. If they are needed afterwards,
+    /// # Arguments
-    /// clone them _before_ calling this function.
     ///
-    /// If `is_ref_mut` is [`true`], the first argument is assumed to be passed
+    /// All arguments may be _consumed_, meaning that they may be replaced by `()`. This is to avoid
-    /// by reference and is not consumed.
+    /// unnecessarily cloning the arguments.
+    ///
+    /// **DO NOT** reuse the arguments after this call. If they are needed afterwards, clone them
+    /// _before_ calling this function.
+    ///
+    /// If `is_ref_mut` is [`true`], the first argument is assumed to be passed by reference and is
+    /// not consumed.
     pub fn call_fn_raw(
         &self,
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         is_ref_mut: bool,
         is_method_call: bool,
         args: &mut [&mut Dynamic],
     ) -> Result<Dynamic, Box<EvalAltResult>> {
+        let fn_name = fn_name.as_ref();
+
         let hash = if is_method_call {
             FnCallHashes::from_all(
                 #[cfg(not(feature = "no_function"))]

src/func/script.rs

@@ -0,0 +1,196 @@
+//! Implement script function-calling mechanism for [`Engine`].
+#![cfg(not(feature = "no_function"))]
+
+use crate::ast::ScriptFnDef;
+use crate::engine::{EvalState, Imports};
+use crate::func::call::FnCallArgs;
+use crate::r#unsafe::unsafe_cast_var_name_to_lifetime;
+use crate::{Dynamic, Engine, EvalAltResult, Module, Position, RhaiResult, Scope, StaticVec};
+use std::mem;
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+
+impl Engine {
+    /// Call a script-defined function.
+    ///
+    /// If `rewind_scope` is `false`, arguments are removed from the scope but new variables are not.
+    ///
+    /// # WARNING
+    ///
+    /// Function call arguments may be _consumed_ when the function requires them to be passed by value.
+    /// All function arguments not in the first position are always passed by value and thus consumed.
+    ///
+    /// **DO NOT** reuse the argument values unless for the first `&mut` argument - all others are silently replaced by `()`!
+    pub(crate) fn call_script_fn(
+        &self,
+        scope: &mut Scope,
+        mods: &mut Imports,
+        state: &mut EvalState,
+        lib: &[&Module],
+        this_ptr: &mut Option<&mut Dynamic>,
+        fn_def: &ScriptFnDef,
+        args: &mut FnCallArgs,
+        pos: Position,
+        rewind_scope: bool,
+        level: usize,
+    ) -> RhaiResult {
+        #[inline(never)]
+        fn make_error(
+            name: String,
+            fn_def: &ScriptFnDef,
+            mods: &Imports,
+            err: Box<EvalAltResult>,
+            pos: Position,
+        ) -> RhaiResult {
+            Err(EvalAltResult::ErrorInFunctionCall(
+                name,
+                fn_def
+                    .lib
+                    .as_ref()
+                    .and_then(|m| m.id().map(|id| id.to_string()))
+                    .or_else(|| mods.source.as_ref().map(|s| s.to_string()))
+                    .unwrap_or_default(),
+                err,
+                pos,
+            )
+            .into())
+        }
+
+        assert!(fn_def.params.len() == args.len());
+
+        #[cfg(not(feature = "unchecked"))]
+        self.inc_operations(&mut mods.num_operations, pos)?;
+
+        if fn_def.body.is_empty() {
+            return Ok(Dynamic::UNIT);
+        }
+
+        // Check for stack overflow
+        #[cfg(not(feature = "unchecked"))]
+        if level > self.max_call_levels() {
+            return Err(EvalAltResult::ErrorStackOverflow(pos).into());
+        }
+
+        let orig_scope_len = scope.len();
+        let orig_mods_len = mods.len();
+
+        // Put arguments into scope as variables
+        // Actually consume the arguments instead of cloning them
+        scope.extend(
+            fn_def
+                .params
+                .iter()
+                .zip(args.iter_mut().map(|v| mem::take(*v)))
+                .map(|(name, value)| {
+                    let var_name: std::borrow::Cow<'_, str> =
+                        unsafe_cast_var_name_to_lifetime(name).into();
+                    (var_name, value)
+                }),
+        );
+
+        // Merge in encapsulated environment, if any
+        let mut lib_merged = StaticVec::with_capacity(lib.len() + 1);
+        let orig_fn_resolution_caches_len = state.fn_resolution_caches_len();
+
+        let lib = if let Some(ref fn_lib) = fn_def.lib {
+            if fn_lib.is_empty() {
+                lib
+            } else {
+                state.push_fn_resolution_cache();
+                lib_merged.push(fn_lib.as_ref());
+                lib_merged.extend(lib.iter().cloned());
+                &lib_merged
+            }
+        } else {
+            lib
+        };
+
+        #[cfg(not(feature = "no_module"))]
+        if !fn_def.mods.is_empty() {
+            fn_def
+                .mods
+                .iter_raw()
+                .for_each(|(n, m)| mods.push(n.clone(), m.clone()));
+        }
+
+        // Evaluate the function
+        let body = &fn_def.body;
+        let result = self
+            .eval_stmt_block(
+                scope,
+                mods,
+                state,
+                lib,
+                this_ptr,
+                body,
+                true,
+                rewind_scope,
+                level,
+            )
+            .or_else(|err| match *err {
+                // Convert return statement to return value
+                EvalAltResult::Return(x, _) => Ok(x),
+                // Error in sub function call
+                EvalAltResult::ErrorInFunctionCall(name, src, err, _) => {
+                    let fn_name = if src.is_empty() {
+                        format!("{} < {}", name, fn_def.name)
+                    } else {
+                        format!("{} @ '{}' < {}", name, src, fn_def.name)
+                    };
+
+                    make_error(fn_name, fn_def, mods, err, pos)
+                }
+                // System errors are passed straight-through
+                mut err if err.is_system_exception() => {
+                    err.set_position(pos);
+                    Err(err.into())
+                }
+                // Other errors are wrapped in `ErrorInFunctionCall`
+                _ => make_error(fn_def.name.to_string(), fn_def, mods, err, pos),
+            });
+
+        // Remove all local variables
+        if rewind_scope {
+            scope.rewind(orig_scope_len);
+        } else if !args.is_empty() {
+            // Remove arguments only, leaving new variables in the scope
+            scope.remove_range(orig_scope_len, args.len())
+        }
+
+        mods.truncate(orig_mods_len);
+        state.rewind_fn_resolution_caches(orig_fn_resolution_caches_len);
+
+        result
+    }
+
+    // Does a scripted function exist?
+    #[must_use]
+    pub(crate) fn has_script_fn(
+        &self,
+        mods: Option<&Imports>,
+        state: &mut EvalState,
+        lib: &[&Module],
+        hash_script: u64,
+    ) -> bool {
+        let cache = state.fn_resolution_cache_mut();
+
+        if let Some(result) = cache.get(&hash_script).map(|v| v.is_some()) {
+            return result;
+        }
+
+        // First check script-defined functions
+        let result = lib.iter().any(|&m| m.contains_fn(hash_script))
+            // Then check the global namespace and packages
+            || self.global_modules.iter().any(|m| m.contains_fn(hash_script))
+            // Then check imported modules
+            || mods.map_or(false, |m| m.contains_fn(hash_script))
+            // Then check sub-modules
+            || self.global_sub_modules.values().any(|m| m.contains_qualified_fn(hash_script));
+
+        if !result {
+            cache.insert(hash_script, None);
+        }
+
+        result
+    }
+}

src/lib.rs

@@ -75,7 +75,6 @@ mod custom_syntax;
 mod engine;
 mod func;
 mod module;
-#[cfg(not(feature = "no_optimize"))]
 mod optimizer;
 pub mod packages;
 mod parser;
@@ -129,27 +128,13 @@ pub use types::{
 /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
 /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
 #[cfg(not(feature = "internals"))]
-#[cfg(not(feature = "no_smartstring"))]
 pub(crate) type Identifier = SmartString;
 
-/// An identifier in Rhai.
-#[cfg(not(feature = "internals"))]
-#[cfg(feature = "no_smartstring")]
-pub(crate) type Identifier = ImmutableString;
-
 /// An identifier in Rhai. [`SmartString`](https://crates.io/crates/smartstring) is used because most
 /// identifiers are ASCII and short, fewer than 23 characters, so they can be stored inline.
 #[cfg(feature = "internals")]
-#[cfg(not(feature = "no_smartstring"))]
-#[deprecated = "this type is volatile and may change"]
 pub type Identifier = SmartString;
 
-/// An identifier in Rhai.
-#[cfg(feature = "internals")]
-#[cfg(feature = "no_smartstring")]
-#[deprecated = "this type is volatile and may change"]
-pub type Identifier = ImmutableString;
-
 /// Alias to [`Rc`][std::rc::Rc] or [`Arc`][std::sync::Arc] depending on the `sync` feature flag.
 pub use func::Shared;
 
@@ -163,10 +148,10 @@ pub(crate) use func::{
 
 pub use rhai_codegen::*;
 
-pub use func::plugin;
+pub use func::{plugin, FuncArgs};
 
 #[cfg(not(feature = "no_function"))]
-pub use func::{Func, FuncArgs};
+pub use func::Func;
 
 #[cfg(not(feature = "no_function"))]
 pub use ast::ScriptFnMetadata;
@@ -176,6 +161,11 @@ pub use ast::ScriptFnMetadata;
 #[cfg(not(feature = "no_index"))]
 pub type Array = Vec<Dynamic>;
 
+/// Variable-sized array of [`u8`] values (byte array).
+/// Not available under `no_index`.
+#[cfg(not(feature = "no_index"))]
+pub type Blob = Vec<u8>;
+
 /// Hash map of [`Dynamic`] values with [`SmartString`](https://crates.io/crates/smartstring) keys.
 /// Not available under `no_object`.
 #[cfg(not(feature = "no_object"))]
@@ -197,26 +187,21 @@ pub use optimizer::OptimizationLevel;
 // Expose internal data structures.
 
 #[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use types::dynamic::{AccessMode, DynamicReadLock, DynamicWriteLock, Variant};
 
 #[cfg(feature = "internals")]
-#[deprecated = "this function is volatile and may change"]
 pub use tokenizer::{get_next_token, parse_string_literal};
 
 #[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use tokenizer::{
     InputStream, MultiInputsStream, Token, TokenIterator, TokenizeState, TokenizerControl,
     TokenizerControlBlock,
 };
 
 #[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use parser::{IdentifierBuilder, ParseState};
 
 #[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use ast::{
     ASTNode, BinaryExpr, CustomExpr, Expr, FnCallExpr, FnCallHashes, Ident, OpAssignment,
     OptionFlags, ScriptFnDef, Stmt, StmtBlock, AST_OPTION_FLAGS::*,
@@ -224,20 +209,12 @@ pub use ast::{
 
 #[cfg(feature = "internals")]
 #[cfg(not(feature = "no_float"))]
-#[deprecated = "this type is volatile and may change"]
 pub use ast::FloatWrapper;
 
 #[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use engine::{EvalState, FnResolutionCache, FnResolutionCacheEntry, Imports};
 
 #[cfg(feature = "internals")]
-#[cfg(not(feature = "unchecked"))]
-#[deprecated = "this type is volatile and may change"]
-pub use engine::Limits;
-
-#[cfg(feature = "internals")]
-#[deprecated = "this type is volatile and may change"]
 pub use module::NamespaceRef;
 
 /// Alias to [`smallvec::SmallVec<[T; 3]>`](https://crates.io/crates/smallvec), which is a
@@ -309,12 +286,8 @@ type StaticVec<T> = smallvec::SmallVec<[T; 3]>;
 #[cfg(feature = "internals")]
 pub type StaticVec<T> = smallvec::SmallVec<[T; 3]>;
 
-#[cfg(not(feature = "no_smartstring"))]
 pub(crate) type SmartString = smartstring::SmartString<smartstring::LazyCompact>;
 
-#[cfg(feature = "no_smartstring")]
-pub(crate) type SmartString = String;
-
 // Compiler guards against mutually-exclusive feature flags
 
 #[cfg(feature = "no_float")]

src/module/mod.rs

@@ -107,12 +107,12 @@ impl FuncInfo {
 ///
 /// The first module name is skipped.  Hashing starts from the _second_ module in the chain.
 #[inline]
-fn calc_native_fn_hash<'a>(
+fn calc_native_fn_hash(
-    modules: impl Iterator<Item = &'a str>,
+    modules: impl Iterator<Item = impl AsRef<str>>,
-    fn_name: &str,
+    fn_name: impl AsRef<str>,
     params: &[TypeId],
 ) -> u64 {
-    let hash_script = calc_qualified_fn_hash(modules, fn_name, params.len());
+    let hash_script = calc_qualified_fn_hash(modules, fn_name.as_ref(), params.len());
     let hash_params = calc_fn_params_hash(params.iter().cloned());
     combine_hashes(hash_script, hash_params)
 }
@@ -190,13 +190,6 @@ impl fmt::Debug for Module {
     }
 }
 
-impl AsRef<Module> for Module {
-    #[inline(always)]
-    fn as_ref(&self) -> &Module {
-        self
-    }
-}
-
 impl<M: AsRef<Module>> Add<M> for &Module {
     type Output = Module;
 
@@ -324,7 +317,9 @@ impl Module {
     #[inline]
     #[must_use]
     pub fn is_empty(&self) -> bool {
-        self.functions.is_empty()
+        self.indexed
+            && !self.contains_indexed_global_functions
+            && self.functions.is_empty()
             && self.all_functions.is_empty()
             && self.variables.is_empty()
             && self.all_variables.is_empty()
@@ -480,7 +475,7 @@ impl Module {
                 namespace: FnNamespace::Internal,
                 access: fn_def.access,
                 params: num_params,
-                param_types: StaticVec::new(),
+                param_types: StaticVec::new_const(),
                 #[cfg(feature = "metadata")]
                 param_names,
                 func: Into::<CallableFunction>::into(fn_def).into(),
@@ -499,13 +494,19 @@ impl Module {
     #[must_use]
     pub fn get_script_fn(
         &self,
-        name: &str,
+        name: impl AsRef<str>,
         num_params: usize,
     ) -> Option<&Shared<crate::ast::ScriptFnDef>> {
-        self.functions
+        if self.functions.is_empty() {
-            .values()
+            None
-            .find(|f| f.params == num_params && f.name == name)
+        } else {
-            .and_then(|f| f.func.get_script_fn_def())
+            let name = name.as_ref();
+
+            self.functions
+                .values()
+                .find(|f| f.params == num_params && f.name == name)
+                .and_then(|f| f.func.get_script_fn_def())
+        }
     }
 
     /// Get a mutable reference to the underlying [`BTreeMap`] of sub-modules.
@@ -621,10 +622,10 @@ impl Module {
     /// In other words, the number of entries should be one larger than the number of parameters.
     #[cfg(feature = "metadata")]
     #[inline]
-    pub fn update_fn_metadata(&mut self, hash_fn: u64, arg_names: &[&str]) -> &mut Self {
+    pub fn update_fn_metadata(&mut self, hash_fn: u64, arg_names: &[impl AsRef<str>]) -> &mut Self {
         let param_names = arg_names
             .iter()
-            .map(|&name| self.identifiers.get(name))
+            .map(|name| self.identifiers.get(name.as_ref()))
             .collect();
 
         if let Some(f) = self.functions.get_mut(&hash_fn) {
@@ -679,10 +680,11 @@ impl Module {
         name: impl AsRef<str> + Into<Identifier>,
         namespace: FnNamespace,
         access: FnAccess,
-        _arg_names: Option<&[&str]>,
+        arg_names: Option<&[&str]>,
         arg_types: &[TypeId],
         func: CallableFunction,
     ) -> u64 {
+        let _arg_names = arg_names;
         let is_method = func.is_method();
 
         let mut param_types: StaticVec<_> = arg_types
@@ -696,13 +698,13 @@ impl Module {
         #[cfg(feature = "metadata")]
         let mut param_names: StaticVec<_> = _arg_names
             .iter()
-            .flat_map(|p| p.iter())
+            .flat_map(|&p| p.iter())
             .map(|&arg| self.identifiers.get(arg))
             .collect();
         #[cfg(feature = "metadata")]
         param_names.shrink_to_fit();
 
-        let hash_fn = calc_native_fn_hash(empty(), name.as_ref(), &param_types);
+        let hash_fn = calc_native_fn_hash(empty::<&str>(), name.as_ref(), &param_types);
 
         self.functions.insert(
             hash_fn,
@@ -739,7 +741,7 @@ impl Module {
     ///
     /// This function is very low level.
     ///
-    /// # Arguments
+    /// ## Arguments
     ///
     /// A list of [`TypeId`]'s is taken as the argument types.
     ///
@@ -878,7 +880,7 @@ impl Module {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn set_getter_fn<ARGS, A, T, F>(&mut self, name: &str, func: F) -> u64
+    pub fn set_getter_fn<ARGS, A, T, F>(&mut self, name: impl AsRef<str>, func: F) -> u64
     where
         A: Variant + Clone,
         T: Variant + Clone,
@@ -919,7 +921,7 @@ impl Module {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn set_setter_fn<ARGS, A, B, F>(&mut self, name: &str, func: F) -> u64
+    pub fn set_setter_fn<ARGS, A, B, F>(&mut self, name: impl AsRef<str>, func: F) -> u64
     where
         A: Variant + Clone,
         B: Variant + Clone,
@@ -1150,6 +1152,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers += other.identifiers;
         self
     }
 
@@ -1169,6 +1172,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers += other.identifiers;
         self
     }
 
@@ -1197,6 +1201,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers.merge(&other.identifiers);
         self
     }
 
@@ -1246,6 +1251,7 @@ impl Module {
         self.all_type_iterators.clear();
         self.indexed = false;
         self.contains_indexed_global_functions = false;
+        self.identifiers.merge(&other.identifiers);
         self
     }
 
@@ -1454,26 +1460,28 @@ impl Module {
 
         // Non-private functions defined become module functions
         #[cfg(not(feature = "no_function"))]
-        ast.lib()
+        if ast.has_functions() {
-            .functions
+            ast.shared_lib()
-            .values()
+                .functions
-            .filter(|f| match f.access {
+                .values()
-                FnAccess::Public => true,
+                .filter(|f| match f.access {
-                FnAccess::Private => false,
+                    FnAccess::Public => true,
-            })
+                    FnAccess::Private => false,
-            .filter(|f| f.func.is_script())
+                })
-            .for_each(|f| {
+                .filter(|f| f.func.is_script())
-                // Encapsulate AST environment
+                .for_each(|f| {
-                let mut func = f
+                    // Encapsulate AST environment
-                    .func
+                    let mut func = f
-                    .get_script_fn_def()
+                        .func
-                    .expect("scripted function")
+                        .get_script_fn_def()
-                    .as_ref()
+                        .expect("scripted function")
-                    .clone();
+                        .as_ref()
-                func.lib = Some(ast.shared_lib());
+                        .clone();
-                func.mods = func_mods.clone();
+                    func.lib = Some(ast.shared_lib().clone());
-                module.set_script_fn(func);
+                    func.mods = func_mods.clone();
-            });
+                    module.set_script_fn(func);
+                });
+        }
 
         if let Some(s) = ast.source_raw() {
             module.set_id(s.clone());
@@ -1661,10 +1669,6 @@ impl Module {
 ///
 /// A [`StaticVec`] is used because most namespace-qualified access contains only one level,
 /// and it is wasteful to always allocate a [`Vec`] with one element.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Clone, Eq, PartialEq, Default, Hash)]
 pub struct NamespaceRef {
     index: Option<NonZeroUsize>,
@@ -1717,6 +1721,17 @@ impl DerefMut for NamespaceRef {
     }
 }
 
+impl From<Vec<Ident>> for NamespaceRef {
+    #[inline(always)]
+    fn from(mut path: Vec<Ident>) -> Self {
+        path.shrink_to_fit();
+        Self {
+            index: None,
+            path: path.into(),
+        }
+    }
+}
+
 impl From<StaticVec<Ident>> for NamespaceRef {
     #[inline(always)]
     fn from(mut path: StaticVec<Ident>) -> Self {
@@ -1729,10 +1744,10 @@ impl NamespaceRef {
     /// Create a new [`NamespaceRef`].
     #[inline(always)]
     #[must_use]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             index: None,
-            path: StaticVec::new(),
+            path: StaticVec::new_const(),
         }
     }
     /// Get the [`Scope`][crate::Scope] index offset.

src/module/resolvers/file.rs

@@ -1,8 +1,9 @@
+#![cfg(not(feature = "no_std"))]
+#![cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
+
 use crate::func::native::shared_write_lock;
 use crate::{Engine, EvalAltResult, Identifier, Module, ModuleResolver, Position, Scope, Shared};
 
-#[cfg(feature = "no_std")]
-use std::prelude::v1::*;
 use std::{
     collections::BTreeMap,
     io::Error as IoError,
@@ -121,7 +122,7 @@ impl FileModuleResolver {
             base_path: None,
             extension: extension.into(),
             cache_enabled: true,
-            cache: Default::default(),
+            cache: BTreeMap::new().into(),
         }
     }
 
@@ -150,7 +151,7 @@ impl FileModuleResolver {
             base_path: Some(path.into()),
             extension: extension.into(),
             cache_enabled: true,
-            cache: Default::default(),
+            cache: BTreeMap::new().into(),
         }
     }
 
@@ -197,12 +198,12 @@ impl FileModuleResolver {
     /// Is a particular path cached?
     #[inline]
     #[must_use]
-    pub fn is_cached(&self, path: &str, source_path: Option<&str>) -> bool {
+    pub fn is_cached(&self, path: impl AsRef<str>, source_path: Option<&str>) -> bool {
         if !self.cache_enabled {
             return false;
         }
 
-        let file_path = self.get_file_path(path, source_path);
+        let file_path = self.get_file_path(path.as_ref(), source_path);
 
         shared_write_lock(&self.cache).contains_key(&file_path)
     }
@@ -219,10 +220,10 @@ impl FileModuleResolver {
     #[must_use]
     pub fn clear_cache_for_path(
         &mut self,
-        path: &str,
+        path: impl AsRef<str>,
-        source_path: Option<&str>,
+        source_path: Option<impl AsRef<str>>,
     ) -> Option<Shared<Module>> {
-        let file_path = self.get_file_path(path, source_path);
+        let file_path = self.get_file_path(path.as_ref(), source_path.as_ref().map(|v| v.as_ref()));
 
         shared_write_lock(&self.cache)
             .remove_entry(&file_path)

src/module/resolvers/mod.rs

@@ -3,21 +3,16 @@ use crate::{Engine, EvalAltResult, Module, Position, Shared, AST};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 
-mod dummy;
-pub use dummy::DummyModuleResolver;
-
 mod collection;
-pub use collection::ModuleResolversCollection;
+mod dummy;
-
-#[cfg(not(feature = "no_std"))]
-#[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
 mod file;
+mod stat;
 
+pub use collection::ModuleResolversCollection;
+pub use dummy::DummyModuleResolver;
 #[cfg(not(feature = "no_std"))]
 #[cfg(not(any(target_arch = "wasm32", target_arch = "wasm64")))]
 pub use file::FileModuleResolver;
-
-mod stat;
 pub use stat::StaticModuleResolver;
 
 /// Trait that encapsulates a module resolution service.

src/optimizer.rs

@@ -1,4 +1,5 @@
 //! Module implementing the [`AST`] optimizer.
+#![cfg(not(feature = "no_optimize"))]
 
 use crate::ast::{Expr, OpAssignment, Stmt, AST_OPTION_FLAGS::*};
 use crate::engine::{
@@ -9,21 +10,19 @@ use crate::func::hashing::get_hasher;
 use crate::tokenizer::Token;
 use crate::types::dynamic::AccessMode;
 use crate::{
-    calc_fn_hash, calc_fn_params_hash, combine_hashes, Dynamic, Engine, FnPtr, ImmutableString,
+    calc_fn_hash, calc_fn_params_hash, combine_hashes, Dynamic, Engine, FnPtr, Position, Scope,
-    Module, Position, Scope, StaticVec, AST,
+    StaticVec, AST,
 };
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 use std::{
     any::TypeId,
+    convert::TryFrom,
     hash::{Hash, Hasher},
     mem,
     ops::DerefMut,
 };
 
-#[cfg(not(feature = "no_closure"))]
-use crate::engine::KEYWORD_IS_SHARED;
-
 /// Level of optimization performed.
 #[derive(Debug, Eq, PartialEq, Hash, Clone, Copy)]
 pub enum OptimizationLevel {
@@ -39,11 +38,7 @@ pub enum OptimizationLevel {
 impl Default for OptimizationLevel {
     #[inline(always)]
     fn default() -> Self {
-        if cfg!(feature = "no_optimize") {
+        Self::Simple
-            Self::None
-        } else {
-            Self::Simple
-        }
     }
 }
 
@@ -58,8 +53,9 @@ struct OptimizerState<'a> {
     propagate_constants: bool,
     /// An [`Engine`] instance for eager function evaluation.
     engine: &'a Engine,
-    /// [Module] containing script-defined functions.
+    /// [Module][crate::Module] containing script-defined functions.
-    lib: &'a [&'a Module],
+    #[cfg(not(feature = "no_function"))]
+    lib: &'a [&'a crate::Module],
     /// Optimization level.
     optimization_level: OptimizationLevel,
 }
@@ -67,16 +63,17 @@ struct OptimizerState<'a> {
 impl<'a> OptimizerState<'a> {
     /// Create a new State.
     #[inline(always)]
-    pub fn new(
+    pub const fn new(
         engine: &'a Engine,
-        lib: &'a [&'a Module],
+        #[cfg(not(feature = "no_function"))] lib: &'a [&'a crate::Module],
         optimization_level: OptimizationLevel,
     ) -> Self {
         Self {
             changed: false,
-            variables: StaticVec::new(),
+            variables: StaticVec::new_const(),
             propagate_constants: true,
             engine,
+            #[cfg(not(feature = "no_function"))]
             lib,
             optimization_level,
         }
@@ -103,16 +100,23 @@ impl<'a> OptimizerState<'a> {
     }
     /// Add a new constant to the list.
     #[inline(always)]
-    pub fn push_var(&mut self, name: &str, access: AccessMode, value: Option<Dynamic>) {
+    pub fn push_var(
+        &mut self,
+        name: impl Into<String>,
+        access: AccessMode,
+        value: Option<Dynamic>,
+    ) {
         self.variables.push((name.into(), access, value))
     }
     /// Look up a constant from the list.
     #[inline]
-    pub fn find_constant(&self, name: &str) -> Option<&Dynamic> {
+    pub fn find_constant(&self, name: impl AsRef<str>) -> Option<&Dynamic> {
         if !self.propagate_constants {
             return None;
         }
 
+        let name = name.as_ref();
+
         for (n, access, value) in self.variables.iter().rev() {
             if n == name {
                 return match access {
@@ -128,16 +132,21 @@ impl<'a> OptimizerState<'a> {
     #[inline]
     pub fn call_fn_with_constant_arguments(
         &self,
-        fn_name: &str,
+        fn_name: impl AsRef<str>,
         arg_values: &mut [Dynamic],
     ) -> Option<Dynamic> {
+        #[cfg(not(feature = "no_function"))]
+        let lib = self.lib;
+        #[cfg(feature = "no_function")]
+        let lib = &[];
+
         self.engine
             .call_native_fn(
                 &mut Imports::new(),
                 &mut EvalState::new(),
-                self.lib,
+                lib,
-                fn_name,
+                &fn_name,
-                calc_fn_hash(fn_name, arg_values.len()),
+                calc_fn_hash(&fn_name, arg_values.len()),
                 &mut arg_values.iter_mut().collect::<StaticVec<_>>(),
                 false,
                 false,
@@ -210,7 +219,7 @@ fn optimize_stmt_block(
 
                         if value_expr.is_constant() {
                             state.push_var(
-                                &x.name,
+                                x.name.as_str(),
                                 AccessMode::ReadOnly,
                                 value_expr.get_literal_value(),
                             );
@@ -218,7 +227,7 @@ fn optimize_stmt_block(
                     } else {
                         // Add variables into the state
                         optimize_expr(value_expr, state, false);
-                        state.push_var(&x.name, AccessMode::ReadWrite, None);
+                        state.push_var(x.name.as_str(), AccessMode::ReadWrite, None);
                     }
                 }
                 // Optimize the statement
@@ -894,7 +903,10 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                 *expr = mem::take(lhs);
             }
             // lhs && rhs
-            (lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, false); }
+            (lhs, rhs) => {
+                optimize_expr(lhs, state, false);
+                optimize_expr(rhs, state, false);
+            }
         },
         // lhs || rhs
         Expr::Or(ref mut x, _) => match (&mut x.lhs, &mut x.rhs) {
@@ -916,7 +928,10 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                 *expr = mem::take(lhs);
             }
             // lhs || rhs
-            (lhs, rhs) => { optimize_expr(lhs, state, false); optimize_expr(rhs, state, false); }
+            (lhs, rhs) => {
+                optimize_expr(lhs, state, false);
+                optimize_expr(rhs, state, false);
+            }
         },
 
         // eval!
@@ -928,24 +943,20 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
             if !x.is_qualified() // Non-qualified
             && state.optimization_level == OptimizationLevel::Simple // simple optimizations
             && x.args.len() == 1
-            && x.args[0].is_constant()
             && x.name == KEYWORD_FN_PTR
+            && x.args[0].is_constant()
         => {
             let fn_name = match x.args[0] {
-                Expr::Stack(slot, _) => Some(x.constants[slot].clone()),
+                Expr::Stack(slot, _) => x.constants[slot].clone(),
-                Expr::StringConstant(ref s, _) => Some(s.clone().into()),
+                Expr::StringConstant(ref s, _) => s.clone().into(),
-                _ => None
+                _ => Dynamic::UNIT
             };
 
-            if let Some(fn_name) = fn_name {
+            if let Ok(fn_ptr) = fn_name.into_immutable_string().map_err(|err| err.into()).and_then(FnPtr::try_from) {
-                if fn_name.is::<ImmutableString>() {
+                state.set_dirty();
-                    state.set_dirty();
+                *expr = Expr::DynamicConstant(Box::new(fn_ptr.into()), *pos);
-                    let fn_ptr = FnPtr::new_unchecked(
+            } else {
-                                    fn_name.as_str_ref().expect("`ImmutableString`").into(),
+                optimize_expr(&mut x.args[0], state, false);
-                                    StaticVec::new()
-                                 );
-                    *expr = Expr::DynamicConstant(Box::new(fn_ptr.into()), *pos);
-                }
             }
         }
 
@@ -975,7 +986,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                     return;
                 }
                 #[cfg(not(feature = "no_closure"))]
-                KEYWORD_IS_SHARED if arg_values.len() == 1 => {
+                crate::engine::KEYWORD_IS_SHARED if arg_values.len() == 1 => {
                     state.set_dirty();
                     *expr = Expr::from_dynamic(Dynamic::FALSE, *pos);
                     return;
@@ -984,7 +995,12 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                 _ if x.args.len() == 2 && !state.has_native_fn_override(x.hashes.native, arg_types.as_ref()) => {
                     if let Some(result) = get_builtin_binary_op_fn(x.name.as_ref(), &arg_values[0], &arg_values[1])
                         .and_then(|f| {
-                            let context = (state.engine, x.name.as_ref(), state.lib).into();
+                            #[cfg(not(feature = "no_function"))]
+                            let lib = state.lib;
+                            #[cfg(feature = "no_function")]
+                            let lib = &[];
+
+                            let context = (state.engine, x.name.as_str(), lib).into();
                             let (first, second) = arg_values.split_first_mut().expect("not empty");
                             (f)(context, &mut [ first, &mut second[0] ]).ok()
                         }) {
@@ -1017,7 +1033,7 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
         => {
             // First search for script-defined functions (can override built-in)
             #[cfg(not(feature = "no_function"))]
-            let has_script_fn = state.lib.iter().any(|&m| m.get_script_fn(x.name.as_ref(), x.args.len()).is_some());
+            let has_script_fn = state.lib.iter().any(|&m| m.get_script_fn(&x.name, x.args.len()).is_some());
             #[cfg(feature = "no_function")]
             let has_script_fn = false;
 
@@ -1030,8 +1046,8 @@ fn optimize_expr(expr: &mut Expr, state: &mut OptimizerState, chaining: bool) {
                 let result = match x.name.as_str() {
                     KEYWORD_TYPE_OF if arg_values.len() == 1 => Some(state.engine.map_type_name(arg_values[0].type_name()).into()),
                     #[cfg(not(feature = "no_closure"))]
-                    KEYWORD_IS_SHARED if arg_values.len() == 1 => Some(Dynamic::FALSE),
+                    crate::engine::KEYWORD_IS_SHARED if arg_values.len() == 1 => Some(Dynamic::FALSE),
-                    _ => state.call_fn_with_constant_arguments(x.name.as_ref(), arg_values)
+                    _ => state.call_fn_with_constant_arguments(&x.name, arg_values)
                 };
 
                 if let Some(result) = result {
@@ -1083,7 +1099,7 @@ fn optimize_top_level(
     statements: StaticVec<Stmt>,
     engine: &Engine,
     scope: &Scope,
-    lib: &[&Module],
+    #[cfg(not(feature = "no_function"))] lib: &[&crate::Module],
     optimization_level: OptimizationLevel,
 ) -> StaticVec<Stmt> {
     let mut statements = statements;
@@ -1095,7 +1111,12 @@ fn optimize_top_level(
     }
 
     // Set up the state
-    let mut state = OptimizerState::new(engine, lib, optimization_level);
+    let mut state = OptimizerState::new(
+        engine,
+        #[cfg(not(feature = "no_function"))]
+        lib,
+        optimization_level,
+    );
 
     // Add constants and variables from the scope
     scope.iter().for_each(|(name, constant, value)| {
@@ -1115,36 +1136,31 @@ pub fn optimize_into_ast(
     engine: &Engine,
     scope: &Scope,
     statements: StaticVec<Stmt>,
-    functions: StaticVec<crate::Shared<crate::ast::ScriptFnDef>>,
+    #[cfg(not(feature = "no_function"))] functions: StaticVec<
+        crate::Shared<crate::ast::ScriptFnDef>,
+    >,
     optimization_level: OptimizationLevel,
 ) -> AST {
-    let level = if cfg!(feature = "no_optimize") {
-        Default::default()
-    } else {
-        optimization_level
-    };
-
     let mut statements = statements;
-    let _functions = functions;
 
     #[cfg(not(feature = "no_function"))]
     let lib = {
-        let mut module = Module::new();
+        let mut module = crate::Module::new();
 
-        if level != OptimizationLevel::None {
+        if optimization_level != OptimizationLevel::None {
             // We only need the script library's signatures for optimization purposes
-            let mut lib2 = Module::new();
+            let mut lib2 = crate::Module::new();
 
-            _functions
+            functions
                 .iter()
                 .map(|fn_def| crate::ast::ScriptFnDef {
                     name: fn_def.name.clone(),
                     access: fn_def.access,
-                    body: crate::ast::StmtBlock::empty(),
+                    body: crate::ast::StmtBlock::NONE,
                     params: fn_def.params.clone(),
                     lib: None,
                     #[cfg(not(feature = "no_module"))]
-                    mods: crate::engine::Imports::new(),
+                    mods: Imports::new(),
                     #[cfg(not(feature = "no_function"))]
                     #[cfg(feature = "metadata")]
                     comments: None,
@@ -1155,7 +1171,7 @@ pub fn optimize_into_ast(
 
             let lib2 = &[&lib2];
 
-            _functions
+            functions
                 .into_iter()
                 .map(|fn_def| {
                     let mut fn_def = crate::func::native::shared_take_or_clone(fn_def);
@@ -1163,7 +1179,8 @@ pub fn optimize_into_ast(
                     // Optimize the function body
                     let body = mem::take(fn_def.body.deref_mut());
 
-                    *fn_def.body = optimize_top_level(body, engine, scope, lib2, level);
+                    *fn_def.body =
+                        optimize_top_level(body, engine, scope, lib2, optimization_level);
 
                     fn_def
                 })
@@ -1171,7 +1188,7 @@ pub fn optimize_into_ast(
                     module.set_script_fn(fn_def);
                 });
         } else {
-            _functions.into_iter().for_each(|fn_def| {
+            functions.into_iter().for_each(|fn_def| {
                 module.set_script_fn(fn_def);
             });
         }
@@ -1179,18 +1196,21 @@ pub fn optimize_into_ast(
         module
     };
 
-    #[cfg(feature = "no_function")]
-    let lib = Module::new();
-
     statements.shrink_to_fit();
 
     AST::new(
-        match level {
+        match optimization_level {
             OptimizationLevel::None => statements,
-            OptimizationLevel::Simple | OptimizationLevel::Full => {
+            OptimizationLevel::Simple | OptimizationLevel::Full => optimize_top_level(
-                optimize_top_level(statements, engine, &scope, &[&lib], level)
+                statements,
-            }
+                engine,
+                &scope,
+                #[cfg(not(feature = "no_function"))]
+                &[&lib],
+                optimization_level,
+            ),
         },
+        #[cfg(not(feature = "no_function"))]
         lib,
     )
 }

src/packages/arithmetic.rs

@@ -329,13 +329,10 @@ mod f32_functions {
     }
     #[rhai_fn(return_raw)]
     pub fn sign(x: f32) -> Result<INT, Box<EvalAltResult>> {
-        if x == 0.0 {
+        match x.signum() {
-            Ok(0)
+            _ if x == 0.0 => Ok(0),
-        } else {
+            x if x.is_nan() => Err(make_err("Sign of NaN is undefined")),
-            match x.signum() {
+            x => Ok(x as INT),
-                x if x.is_nan() => Err(make_err("Sign of NaN is undefined")),
-                x => Ok(x as INT),
-            }
         }
     }
     pub fn is_zero(x: f32) -> bool {
@@ -439,13 +436,10 @@ mod f64_functions {
     }
     #[rhai_fn(return_raw)]
     pub fn sign(x: f64) -> Result<INT, Box<EvalAltResult>> {
-        if x == 0.0 {
+        match x.signum() {
-            Ok(0)
+            _ if x == 0.0 => Ok(0),
-        } else {
+            x if x.is_nan() => Err(make_err("Sign of NaN is undefined")),
-            match x.signum() {
+            x => Ok(x as INT),
-                x if x.is_nan() => Err(make_err("Sign of NaN is undefined")),
-                x => Ok(x as INT),
-            }
         }
     }
     pub fn is_zero(x: f64) -> bool {

src/packages/array_basic.rs

@@ -69,7 +69,7 @@ mod array_functions {
     }
     #[rhai_fn(return_raw)]
     pub fn pad(
-        _ctx: NativeCallContext,
+        ctx: NativeCallContext,
         array: &mut Array,
         len: INT,
         item: Dynamic,
@@ -78,6 +78,8 @@ mod array_functions {
             return Ok(());
         }
 
+        let _ctx = ctx;
+
         // Check if array will be over max size limit
         #[cfg(not(feature = "unchecked"))]
         if _ctx.engine().max_array_size() > 0 && (len as usize) > _ctx.engine().max_array_size() {
@@ -250,7 +252,36 @@ mod array_functions {
         array: &mut Array,
         mapper: FnPtr,
     ) -> Result<Array, Box<EvalAltResult>> {
-        map_with_fn_name(ctx, array, mapper.fn_name())
+        if array.is_empty() {
+            return Ok(array.clone());
+        }
+
+        let mut ar = Array::with_capacity(array.len());
+
+        for (i, item) in array.iter().enumerate() {
+            ar.push(
+                mapper
+                    .call_raw(&ctx, None, [item.clone()])
+                    .or_else(|err| match *err {
+                        EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
+                            if fn_sig.starts_with(mapper.fn_name()) =>
+                        {
+                            mapper.call_raw(&ctx, None, [item.clone(), (i as INT).into()])
+                        }
+                        _ => Err(err),
+                    })
+                    .map_err(|err| {
+                        Box::new(EvalAltResult::ErrorInFunctionCall(
+                            "map".to_string(),
+                            ctx.source().unwrap_or("").to_string(),
+                            err,
+                            Position::NONE,
+                        ))
+                    })?,
+            );
+        }
+
+        Ok(ar)
     }
     #[rhai_fn(name = "map", return_raw, pure)]
     pub fn map_with_fn_name(
@@ -258,94 +289,57 @@ mod array_functions {
         array: &mut Array,
         mapper: &str,
     ) -> Result<Array, Box<EvalAltResult>> {
-        if array.is_empty() {
+        map(ctx, array, FnPtr::new(mapper)?)
-            return Ok(Array::new());
-        }
-
-        let mut ar = Array::with_capacity(array.len());
-        let mut index_val = Dynamic::UNIT;
-
-        for (i, item) in array.iter_mut().enumerate() {
-            let mut args = [item, &mut index_val];
-
-            ar.push(match ctx.call_fn_raw(mapper, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
-                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(mapper) =>
-                    {
-                        *args[1] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(mapper, true, false, &mut args)?
-                    }
-                    _ => {
-                        return Err(EvalAltResult::ErrorInFunctionCall(
-                            "map".to_string(),
-                            ctx.source().unwrap_or("").to_string(),
-                            err,
-                            Position::NONE,
-                        )
-                        .into())
-                    }
-                },
-            });
-        }
-
-        Ok(ar)
     }
+
     #[rhai_fn(return_raw, pure)]
     pub fn filter(
         ctx: NativeCallContext,
         array: &mut Array,
         filter: FnPtr,
-    ) -> Result<Array, Box<EvalAltResult>> {
-        filter_with_fn_name(ctx, array, filter.fn_name())
-    }
-    #[rhai_fn(name = "filter", return_raw, pure)]
-    pub fn filter_with_fn_name(
-        ctx: NativeCallContext,
-        array: &mut Array,
-        filter: &str,
     ) -> Result<Array, Box<EvalAltResult>> {
         if array.is_empty() {
             return Ok(array.clone());
         }
 
         let mut ar = Array::new();
-        let mut index_val = Dynamic::UNIT;
 
-        for (i, item) in array.iter_mut().enumerate() {
+        for (i, item) in array.iter().enumerate() {
-            let mut args = [item, &mut index_val];
+            if filter
-
+                .call_raw(&ctx, None, [item.clone()])
-            let keep = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
+                .or_else(|err| match *err {
-                Ok(r) => r,
-                Err(err) => match *err {
                     EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
+                        if fn_sig.starts_with(filter.fn_name()) =>
                     {
-                        *args[1] = Dynamic::from(i as INT);
+                        filter.call_raw(&ctx, None, [item.clone(), (i as INT).into()])
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
                     }
-                    _ => {
+                    _ => Err(err),
-                        return Err(EvalAltResult::ErrorInFunctionCall(
+                })
-                            "filter".to_string(),
+                .map_err(|err| {
-                            ctx.source().unwrap_or("").to_string(),
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
-                            err,
+                        "filter".to_string(),
-                            Position::NONE,
+                        ctx.source().unwrap_or("").to_string(),
-                        )
+                        err,
-                        .into())
+                        Position::NONE,
-                    }
+                    ))
-                },
+                })?
-            }
+                .as_bool()
-            .as_bool()
+                .unwrap_or(false)
-            .unwrap_or(false);
+            {
-
+                ar.push(item.clone());
-            if keep {
-                ar.push(args[0].clone());
             }
         }
 
         Ok(ar)
     }
+    #[rhai_fn(name = "filter", return_raw, pure)]
+    pub fn filter_with_fn_name(
+        ctx: NativeCallContext,
+        array: &mut Array,
+        filter_func: &str,
+    ) -> Result<Array, Box<EvalAltResult>> {
+        filter(ctx, array, FnPtr::new(filter_func)?)
+    }
     #[rhai_fn(return_raw, pure)]
     pub fn contains(
         ctx: NativeCallContext,
@@ -466,15 +460,6 @@ mod array_functions {
         array: &mut Array,
         filter: FnPtr,
         start: INT,
-    ) -> Result<INT, Box<EvalAltResult>> {
-        index_of_with_fn_name_filter_starting_from(ctx, array, filter.fn_name(), start)
-    }
-    #[rhai_fn(name = "index_of", return_raw, pure)]
-    pub fn index_of_with_fn_name_filter_starting_from(
-        ctx: NativeCallContext,
-        array: &mut Array,
-        filter: &str,
-        start: INT,
     ) -> Result<INT, Box<EvalAltResult>> {
         if array.is_empty() {
             return Ok(-1);
@@ -491,48 +476,80 @@ mod array_functions {
             start as usize
         };
 
-        let mut index_val = Dynamic::UNIT;
+        for (i, item) in array.iter().enumerate().skip(start) {
-
+            if filter
-        for (i, item) in array.iter_mut().enumerate().skip(start) {
+                .call_raw(&ctx, None, [item.clone()])
-            let mut args = [item, &mut index_val];
+                .or_else(|err| match *err {
-
-            let found = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
                     EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
+                        if fn_sig.starts_with(filter.fn_name()) =>
                     {
-                        *args[1] = Dynamic::from(i as INT);
+                        filter.call_raw(&ctx, None, [item.clone(), (i as INT).into()])
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
                     }
-                    _ => {
+                    _ => Err(err),
-                        return Err(EvalAltResult::ErrorInFunctionCall(
+                })
-                            "index_of".to_string(),
+                .map_err(|err| {
-                            ctx.source().unwrap_or("").to_string(),
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
-                            err,
+                        "index_of".to_string(),
-                            Position::NONE,
+                        ctx.source().unwrap_or("").to_string(),
-                        )
+                        err,
-                        .into())
+                        Position::NONE,
-                    }
+                    ))
-                },
+                })?
-            }
+                .as_bool()
-            .as_bool()
+                .unwrap_or(false)
-            .unwrap_or(false);
+            {
-
-            if found {
                 return Ok(i as INT);
             }
         }
 
         Ok(-1 as INT)
     }
+    #[rhai_fn(name = "index_of", return_raw, pure)]
+    pub fn index_of_with_fn_name_filter_starting_from(
+        ctx: NativeCallContext,
+        array: &mut Array,
+        filter: &str,
+        start: INT,
+    ) -> Result<INT, Box<EvalAltResult>> {
+        index_of_filter_starting_from(ctx, array, FnPtr::new(filter)?, start)
+    }
     #[rhai_fn(return_raw, pure)]
     pub fn some(
         ctx: NativeCallContext,
         array: &mut Array,
         filter: FnPtr,
     ) -> Result<bool, Box<EvalAltResult>> {
-        some_with_fn_name(ctx, array, filter.fn_name())
+        if array.is_empty() {
+            return Ok(false);
+        }
+
+        for (i, item) in array.iter().enumerate() {
+            if filter
+                .call_raw(&ctx, None, [item.clone()])
+                .or_else(|err| match *err {
+                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
+                        if fn_sig.starts_with(filter.fn_name()) =>
+                    {
+                        filter.call_raw(&ctx, None, [item.clone(), (i as INT).into()])
+                    }
+                    _ => Err(err),
+                })
+                .map_err(|err| {
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
+                        "some".to_string(),
+                        ctx.source().unwrap_or("").to_string(),
+                        err,
+                        Position::NONE,
+                    ))
+                })?
+                .as_bool()
+                .unwrap_or(false)
+            {
+                return Ok(true);
+            }
+        }
+
+        Ok(false)
     }
     #[rhai_fn(name = "some", return_raw, pure)]
     pub fn some_with_fn_name(
@@ -540,44 +557,7 @@ mod array_functions {
         array: &mut Array,
         filter: &str,
     ) -> Result<bool, Box<EvalAltResult>> {
-        if array.is_empty() {
+        some(ctx, array, FnPtr::new(filter)?)
-            return Ok(false);
-        }
-
-        let mut index_val = Dynamic::UNIT;
-
-        for (i, item) in array.iter_mut().enumerate() {
-            let mut args = [item, &mut index_val];
-
-            let found = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
-                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
-                    {
-                        *args[1] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
-                    }
-                    _ => {
-                        return Err(EvalAltResult::ErrorInFunctionCall(
-                            "some".to_string(),
-                            ctx.source().unwrap_or("").to_string(),
-                            err,
-                            Position::NONE,
-                        )
-                        .into())
-                    }
-                },
-            }
-            .as_bool()
-            .unwrap_or(false);
-
-            if found {
-                return Ok(true);
-            }
-        }
-
-        Ok(false)
     }
     #[rhai_fn(return_raw, pure)]
     pub fn all(
@@ -585,7 +565,37 @@ mod array_functions {
         array: &mut Array,
         filter: FnPtr,
     ) -> Result<bool, Box<EvalAltResult>> {
-        all_with_fn_name(ctx, array, filter.fn_name())
+        if array.is_empty() {
+            return Ok(true);
+        }
+
+        for (i, item) in array.iter().enumerate() {
+            if !filter
+                .call_raw(&ctx, None, [item.clone()])
+                .or_else(|err| match *err {
+                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
+                        if fn_sig.starts_with(filter.fn_name()) =>
+                    {
+                        filter.call_raw(&ctx, None, [item.clone(), (i as INT).into()])
+                    }
+                    _ => Err(err),
+                })
+                .map_err(|err| {
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
+                        "all".to_string(),
+                        ctx.source().unwrap_or("").to_string(),
+                        err,
+                        Position::NONE,
+                    ))
+                })?
+                .as_bool()
+                .unwrap_or(false)
+            {
+                return Ok(false);
+            }
+        }
+
+        Ok(true)
     }
     #[rhai_fn(name = "all", return_raw, pure)]
     pub fn all_with_fn_name(
@@ -593,44 +603,7 @@ mod array_functions {
         array: &mut Array,
         filter: &str,
     ) -> Result<bool, Box<EvalAltResult>> {
-        if array.is_empty() {
+        all(ctx, array, FnPtr::new(filter)?)
-            return Ok(true);
-        }
-
-        let mut index_val = Dynamic::UNIT;
-
-        for (i, item) in array.iter_mut().enumerate() {
-            let mut args = [item, &mut index_val];
-
-            let found = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
-                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
-                    {
-                        *args[1] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
-                    }
-                    _ => {
-                        return Err(EvalAltResult::ErrorInFunctionCall(
-                            "all".to_string(),
-                            ctx.source().unwrap_or("").to_string(),
-                            err,
-                            Position::NONE,
-                        )
-                        .into())
-                    }
-                },
-            }
-            .as_bool()
-            .unwrap_or(false);
-
-            if !found {
-                return Ok(false);
-            }
-        }
-
-        Ok(true)
     }
     #[rhai_fn(return_raw)]
     pub fn dedup(ctx: NativeCallContext, array: &mut Array) -> Result<(), Box<EvalAltResult>> {
@@ -641,23 +614,14 @@ mod array_functions {
         ctx: NativeCallContext,
         array: &mut Array,
         comparer: FnPtr,
-    ) -> Result<(), Box<EvalAltResult>> {
-        dedup_with_fn_name(ctx, array, comparer.fn_name())
-    }
-    #[rhai_fn(name = "dedup", return_raw)]
-    fn dedup_with_fn_name(
-        ctx: NativeCallContext,
-        array: &mut Array,
-        comparer: &str,
     ) -> Result<(), Box<EvalAltResult>> {
         if array.is_empty() {
             return Ok(());
         }
 
         array.dedup_by(|x, y| {
-            let mut args = [x, &mut y.clone()];
+            comparer
-
+                .call_raw(&ctx, None, [x.clone(), y.clone()])
-            ctx.call_fn_raw(comparer, true, false, &mut args)
                 .unwrap_or_else(|_| Dynamic::FALSE)
                 .as_bool()
                 .unwrap_or(false)
@@ -665,13 +629,21 @@ mod array_functions {
 
         Ok(())
     }
+    #[rhai_fn(name = "dedup", return_raw)]
+    fn dedup_with_fn_name(
+        ctx: NativeCallContext,
+        array: &mut Array,
+        comparer: &str,
+    ) -> Result<(), Box<EvalAltResult>> {
+        dedup_by_comparer(ctx, array, FnPtr::new(comparer)?)
+    }
     #[rhai_fn(return_raw, pure)]
     pub fn reduce(
         ctx: NativeCallContext,
         array: &mut Array,
         reducer: FnPtr,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_with_fn_name(ctx, array, reducer.fn_name())
+        reduce_with_initial(ctx, array, reducer, Dynamic::UNIT)
     }
     #[rhai_fn(name = "reduce", return_raw, pure)]
     pub fn reduce_with_fn_name(
@@ -679,7 +651,7 @@ mod array_functions {
         array: &mut Array,
         reducer: &str,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_with_fn_name_with_initial(ctx, array, reducer, Dynamic::UNIT)
+        reduce(ctx, array, FnPtr::new(reducer)?)
     }
     #[rhai_fn(name = "reduce", return_raw, pure)]
     pub fn reduce_with_initial(
@@ -687,35 +659,23 @@ mod array_functions {
         array: &mut Array,
         reducer: FnPtr,
         initial: Dynamic,
-    ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_with_fn_name_with_initial(ctx, array, reducer.fn_name(), initial)
-    }
-    #[rhai_fn(name = "reduce", return_raw, pure)]
-    pub fn reduce_with_fn_name_with_initial(
-        ctx: NativeCallContext,
-        array: &mut Array,
-        reducer: &str,
-        initial: Dynamic,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
         if array.is_empty() {
             return Ok(initial);
         }
 
         let mut result = initial;
-        let mut index_val = Dynamic::UNIT;
 
-        for (i, item) in array.iter_mut().enumerate() {
+        for (i, item) in array.iter().enumerate() {
-            let mut args = [&mut result, &mut item.clone(), &mut index_val];
+            let item = item.clone();
 
-            result = ctx
+            result = reducer
-                .call_fn_raw(reducer, true, false, &mut args[..2])
+                .call_raw(&ctx, None, [result.clone(), item.clone()])
                 .or_else(|err| match *err {
                     EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(reducer) =>
+                        if fn_sig.starts_with(reducer.fn_name()) =>
                     {
-                        *args[1] = item.clone();
+                        reducer.call_raw(&ctx, None, [result, item, (i as INT).into()])
-                        *args[2] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(reducer, true, false, &mut args)
                     }
                     _ => Err(err),
                 })
@@ -731,13 +691,22 @@ mod array_functions {
 
         Ok(result)
     }
+    #[rhai_fn(name = "reduce", return_raw, pure)]
+    pub fn reduce_with_fn_name_with_initial(
+        ctx: NativeCallContext,
+        array: &mut Array,
+        reducer: &str,
+        initial: Dynamic,
+    ) -> Result<Dynamic, Box<EvalAltResult>> {
+        reduce_with_initial(ctx, array, FnPtr::new(reducer)?, initial)
+    }
     #[rhai_fn(return_raw, pure)]
     pub fn reduce_rev(
         ctx: NativeCallContext,
         array: &mut Array,
         reducer: FnPtr,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_rev_with_fn_name(ctx, array, reducer.fn_name())
+        reduce_rev_with_initial(ctx, array, reducer, Dynamic::UNIT)
     }
     #[rhai_fn(name = "reduce_rev", return_raw, pure)]
     pub fn reduce_rev_with_fn_name(
@@ -745,7 +714,7 @@ mod array_functions {
         array: &mut Array,
         reducer: &str,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_rev_with_fn_name_with_initial(ctx, array, reducer, Dynamic::UNIT)
+        reduce_rev(ctx, array, FnPtr::new(reducer)?)
     }
     #[rhai_fn(name = "reduce_rev", return_raw, pure)]
     pub fn reduce_rev_with_initial(
@@ -753,35 +722,24 @@ mod array_functions {
         array: &mut Array,
         reducer: FnPtr,
         initial: Dynamic,
-    ) -> Result<Dynamic, Box<EvalAltResult>> {
-        reduce_rev_with_fn_name_with_initial(ctx, array, reducer.fn_name(), initial)
-    }
-    #[rhai_fn(name = "reduce_rev", return_raw, pure)]
-    pub fn reduce_rev_with_fn_name_with_initial(
-        ctx: NativeCallContext,
-        array: &mut Array,
-        reducer: &str,
-        initial: Dynamic,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
         if array.is_empty() {
             return Ok(initial);
         }
 
         let mut result = initial;
-        let mut index_val = Dynamic::UNIT;
+        let len = array.len();
 
-        for (i, item) in array.iter_mut().enumerate().rev() {
+        for (i, item) in array.iter().rev().enumerate() {
-            let mut args = [&mut result, &mut item.clone(), &mut index_val];
+            let item = item.clone();
 
-            result = ctx
+            result = reducer
-                .call_fn_raw(reducer, true, false, &mut args[..2])
+                .call_raw(&ctx, None, [result.clone(), item.clone()])
                 .or_else(|err| match *err {
                     EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(reducer) =>
+                        if fn_sig.starts_with(reducer.fn_name()) =>
                     {
-                        *args[1] = item.clone();
+                        reducer.call_raw(&ctx, None, [result, item, ((len - 1 - i) as INT).into()])
-                        *args[2] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(reducer, true, false, &mut args)
                     }
                     _ => Err(err),
                 })
@@ -797,6 +755,15 @@ mod array_functions {
 
         Ok(result)
     }
+    #[rhai_fn(name = "reduce_rev", return_raw, pure)]
+    pub fn reduce_rev_with_fn_name_with_initial(
+        ctx: NativeCallContext,
+        array: &mut Array,
+        reducer: &str,
+        initial: Dynamic,
+    ) -> Result<Dynamic, Box<EvalAltResult>> {
+        reduce_rev_with_initial(ctx, array, FnPtr::new(reducer)?, initial)
+    }
     #[rhai_fn(name = "sort", return_raw)]
     pub fn sort_with_fn_name(
         ctx: NativeCallContext,
@@ -817,7 +784,7 @@ mod array_functions {
 
         array.sort_by(|x, y| {
             comparer
-                .call_dynamic(&ctx, None, [x.clone(), y.clone()])
+                .call_raw(&ctx, None, [x.clone(), y.clone()])
                 .ok()
                 .and_then(|v| v.as_int().ok())
                 .map(|v| match v {
@@ -903,13 +870,52 @@ mod array_functions {
 
         Ok(())
     }
-    #[rhai_fn(return_raw, pure)]
+    #[rhai_fn(return_raw)]
     pub fn drain(
         ctx: NativeCallContext,
         array: &mut Array,
         filter: FnPtr,
     ) -> Result<Array, Box<EvalAltResult>> {
-        drain_with_fn_name(ctx, array, filter.fn_name())
+        if array.is_empty() {
+            return Ok(Array::new());
+        }
+
+        let mut drained = Array::with_capacity(array.len());
+
+        let mut i = 0;
+        let mut x = 0;
+
+        while x < array.len() {
+            if filter
+                .call_raw(&ctx, None, [array[x].clone()])
+                .or_else(|err| match *err {
+                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
+                        if fn_sig.starts_with(filter.fn_name()) =>
+                    {
+                        filter.call_raw(&ctx, None, [array[x].clone(), (i as INT).into()])
+                    }
+                    _ => Err(err),
+                })
+                .map_err(|err| {
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
+                        "drain".to_string(),
+                        ctx.source().unwrap_or("").to_string(),
+                        err,
+                        Position::NONE,
+                    ))
+                })?
+                .as_bool()
+                .unwrap_or(false)
+            {
+                drained.push(array.remove(x));
+            } else {
+                x += 1;
+            }
+
+            i += 1;
+        }
+
+        Ok(drained)
     }
     #[rhai_fn(name = "drain", return_raw)]
     pub fn drain_with_fn_name(
@@ -917,65 +923,7 @@ mod array_functions {
         array: &mut Array,
         filter: &str,
     ) -> Result<Array, Box<EvalAltResult>> {
-        if array.is_empty() {
+        drain(ctx, array, FnPtr::new(filter)?)
-            return Ok(Array::new());
-        }
-
-        let mut index_val = Dynamic::UNIT;
-        let mut removed = Vec::with_capacity(array.len());
-        let mut count = 0;
-
-        for (i, item) in array.iter_mut().enumerate() {
-            let mut args = [item, &mut index_val];
-
-            let remove = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
-                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
-                    {
-                        *args[1] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
-                    }
-                    _ => {
-                        return Err(EvalAltResult::ErrorInFunctionCall(
-                            "drain".to_string(),
-                            ctx.source().unwrap_or("").to_string(),
-                            err,
-                            Position::NONE,
-                        )
-                        .into())
-                    }
-                },
-            }
-            .as_bool()
-            .unwrap_or(false);
-
-            removed.push(remove);
-
-            if remove {
-                count += 1;
-            }
-        }
-
-        if count == 0 {
-            return Ok(Array::new());
-        }
-
-        let mut result = Vec::with_capacity(count);
-        let mut x = 0;
-        let mut i = 0;
-
-        while i < array.len() {
-            if removed[x] {
-                result.push(array.remove(i));
-            } else {
-                i += 1;
-            }
-            x += 1;
-        }
-
-        Ok(result.into())
     }
     #[rhai_fn(name = "drain")]
     pub fn drain_range(array: &mut Array, start: INT, len: INT) -> Array {
@@ -1004,13 +952,52 @@ mod array_functions {
 
         array.drain(start..start + len).collect()
     }
-    #[rhai_fn(return_raw, pure)]
+    #[rhai_fn(return_raw)]
     pub fn retain(
         ctx: NativeCallContext,
         array: &mut Array,
         filter: FnPtr,
     ) -> Result<Array, Box<EvalAltResult>> {
-        retain_with_fn_name(ctx, array, filter.fn_name())
+        if array.is_empty() {
+            return Ok(Array::new());
+        }
+
+        let mut drained = Array::new();
+
+        let mut i = 0;
+        let mut x = 0;
+
+        while x < array.len() {
+            if !filter
+                .call_raw(&ctx, None, [array[x].clone()])
+                .or_else(|err| match *err {
+                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
+                        if fn_sig.starts_with(filter.fn_name()) =>
+                    {
+                        filter.call_raw(&ctx, None, [array[x].clone(), (i as INT).into()])
+                    }
+                    _ => Err(err),
+                })
+                .map_err(|err| {
+                    Box::new(EvalAltResult::ErrorInFunctionCall(
+                        "retain".to_string(),
+                        ctx.source().unwrap_or("").to_string(),
+                        err,
+                        Position::NONE,
+                    ))
+                })?
+                .as_bool()
+                .unwrap_or(false)
+            {
+                drained.push(array.remove(x));
+            } else {
+                x += 1;
+            }
+
+            i += 1;
+        }
+
+        Ok(drained)
     }
     #[rhai_fn(name = "retain", return_raw)]
     pub fn retain_with_fn_name(
@@ -1018,65 +1005,7 @@ mod array_functions {
         array: &mut Array,
         filter: &str,
     ) -> Result<Array, Box<EvalAltResult>> {
-        if array.is_empty() {
+        retain(ctx, array, FnPtr::new(filter)?)
-            return Ok(Array::new());
-        }
-
-        let mut index_val = Dynamic::UNIT;
-        let mut removed = Vec::with_capacity(array.len());
-        let mut count = 0;
-
-        for (i, item) in array.iter_mut().enumerate() {
-            let mut args = [item, &mut index_val];
-
-            let keep = match ctx.call_fn_raw(filter, true, false, &mut args[..1]) {
-                Ok(r) => r,
-                Err(err) => match *err {
-                    EvalAltResult::ErrorFunctionNotFound(fn_sig, _)
-                        if fn_sig.starts_with(filter) =>
-                    {
-                        *args[1] = Dynamic::from(i as INT);
-                        ctx.call_fn_raw(filter, true, false, &mut args)?
-                    }
-                    _ => {
-                        return Err(EvalAltResult::ErrorInFunctionCall(
-                            "retain".to_string(),
-                            ctx.source().unwrap_or("").to_string(),
-                            err,
-                            Position::NONE,
-                        )
-                        .into())
-                    }
-                },
-            }
-            .as_bool()
-            .unwrap_or(false);
-
-            removed.push(!keep);
-
-            if !keep {
-                count += 1;
-            }
-        }
-
-        if count == 0 {
-            return Ok(Array::new());
-        }
-
-        let mut result = Vec::with_capacity(count);
-        let mut x = 0;
-        let mut i = 0;
-
-        while i < array.len() {
-            if removed[x] {
-                result.push(array.remove(i));
-            } else {
-                i += 1;
-            }
-            x += 1;
-        }
-
-        Ok(result.into())
     }
     #[rhai_fn(name = "retain")]
     pub fn retain_range(array: &mut Array, start: INT, len: INT) -> Array {

src/packages/blob_basic.rs

@@ -0,0 +1,354 @@
+#![cfg(not(feature = "no_index"))]
+#![allow(non_snake_case)]
+
+use crate::plugin::*;
+use crate::{def_package, Blob, Dynamic, EvalAltResult, NativeCallContext, Position, INT};
+#[cfg(feature = "no_std")]
+use std::prelude::v1::*;
+use std::{any::TypeId, mem};
+
+def_package!(crate:BasicBlobPackage:"Basic BLOB utilities.", lib, {
+    lib.standard = true;
+
+    combine_with_exported_module!(lib, "blob", blob_functions);
+
+    // Register blob iterator
+    lib.set_iterable::<Blob>();
+});
+
+#[export_module]
+mod blob_functions {
+    pub fn blob() -> Blob {
+        Blob::new()
+    }
+    #[rhai_fn(name = "blob", return_raw)]
+    pub fn blob_with_capacity(
+        ctx: NativeCallContext,
+        len: INT,
+    ) -> Result<Blob, Box<EvalAltResult>> {
+        blob_with_capacity_and_value(ctx, len, 0)
+    }
+    #[rhai_fn(name = "blob", return_raw)]
+    pub fn blob_with_capacity_and_value(
+        ctx: NativeCallContext,
+        len: INT,
+        value: INT,
+    ) -> Result<Blob, Box<EvalAltResult>> {
+        let len = if len < 0 { 0 } else { len as usize };
+        let _ctx = ctx;
+
+        // Check if blob will be over max size limit
+        #[cfg(not(feature = "unchecked"))]
+        if _ctx.engine().max_array_size() > 0 && len > _ctx.engine().max_array_size() {
+            return Err(EvalAltResult::ErrorDataTooLarge(
+                "Size of BLOB".to_string(),
+                Position::NONE,
+            )
+            .into());
+        }
+
+        let mut blob = Blob::new();
+        blob.resize(len, (value & 0x000f) as u8);
+        Ok(blob)
+    }
+    #[rhai_fn(name = "len", get = "len", pure)]
+    pub fn len(blob: &mut Blob) -> INT {
+        blob.len() as INT
+    }
+    #[rhai_fn(name = "push", name = "+=")]
+    pub fn push(blob: &mut Blob, item: INT) {
+        let item = (item & 0x000f) as u8;
+        blob.push(item);
+    }
+    #[rhai_fn(name = "append", name = "+=")]
+    pub fn append(blob: &mut Blob, y: Blob) {
+        if !y.is_empty() {
+            if blob.is_empty() {
+                *blob = y;
+            } else {
+                blob.extend(y);
+            }
+        }
+    }
+    #[rhai_fn(name = "+")]
+    pub fn concat(mut blob: Blob, y: Blob) -> Blob {
+        if !y.is_empty() {
+            if blob.is_empty() {
+                blob = y;
+            } else {
+                blob.extend(y);
+            }
+        }
+        blob
+    }
+    pub fn insert(blob: &mut Blob, position: INT, item: INT) {
+        let item = (item & 0x000f) as u8;
+
+        if blob.is_empty() {
+            blob.push(item);
+        } else if position < 0 {
+            if let Some(n) = position.checked_abs() {
+                if n as usize > blob.len() {
+                    blob.insert(0, item);
+                } else {
+                    blob.insert(blob.len() - n as usize, item);
+                }
+            } else {
+                blob.insert(0, item);
+            }
+        } else if (position as usize) >= blob.len() {
+            blob.push(item);
+        } else {
+            blob.insert(position as usize, item);
+        }
+    }
+    #[rhai_fn(return_raw)]
+    pub fn pad(
+        ctx: NativeCallContext,
+        blob: &mut Blob,
+        len: INT,
+        item: INT,
+    ) -> Result<(), Box<EvalAltResult>> {
+        if len <= 0 {
+            return Ok(());
+        }
+
+        let item = (item & 0x000f) as u8;
+        let _ctx = ctx;
+
+        // Check if blob will be over max size limit
+        #[cfg(not(feature = "unchecked"))]
+        if _ctx.engine().max_array_size() > 0 && (len as usize) > _ctx.engine().max_array_size() {
+            return Err(EvalAltResult::ErrorDataTooLarge(
+                "Size of BLOB".to_string(),
+                Position::NONE,
+            )
+            .into());
+        }
+
+        if len as usize > blob.len() {
+            blob.resize(len as usize, item);
+        }
+
+        Ok(())
+    }
+    pub fn pop(blob: &mut Blob) -> INT {
+        if blob.is_empty() {
+            0
+        } else {
+            blob.pop().map_or_else(|| 0, |v| v as INT)
+        }
+    }
+    pub fn shift(blob: &mut Blob) -> INT {
+        if blob.is_empty() {
+            0
+        } else {
+            blob.remove(0) as INT
+        }
+    }
+    pub fn remove(blob: &mut Blob, len: INT) -> INT {
+        if len < 0 || (len as usize) >= blob.len() {
+            0
+        } else {
+            blob.remove(len as usize) as INT
+        }
+    }
+    pub fn clear(blob: &mut Blob) {
+        if !blob.is_empty() {
+            blob.clear();
+        }
+    }
+    pub fn truncate(blob: &mut Blob, len: INT) {
+        if !blob.is_empty() {
+            if len >= 0 {
+                blob.truncate(len as usize);
+            } else {
+                blob.clear();
+            }
+        }
+    }
+    pub fn chop(blob: &mut Blob, len: INT) {
+        if !blob.is_empty() && len as usize >= blob.len() {
+            if len >= 0 {
+                blob.drain(0..blob.len() - len as usize);
+            } else {
+                blob.clear();
+            }
+        }
+    }
+    pub fn reverse(blob: &mut Blob) {
+        if !blob.is_empty() {
+            blob.reverse();
+        }
+    }
+    pub fn splice(blob: &mut Blob, start: INT, len: INT, replace: Blob) {
+        if blob.is_empty() {
+            *blob = replace;
+            return;
+        }
+
+        let start = if start < 0 {
+            let arr_len = blob.len();
+            start
+                .checked_abs()
+                .map_or(0, |n| arr_len - (n as usize).min(arr_len))
+        } else if start as usize >= blob.len() {
+            blob.extend(replace.into_iter());
+            return;
+        } else {
+            start as usize
+        };
+
+        let len = if len < 0 {
+            0
+        } else if len as usize > blob.len() - start {
+            blob.len() - start
+        } else {
+            len as usize
+        };
+
+        blob.splice(start..start + len, replace.into_iter());
+    }
+    pub fn extract(blob: &mut Blob, start: INT, len: INT) -> Blob {
+        if blob.is_empty() || len <= 0 {
+            return Blob::new();
+        }
+
+        let start = if start < 0 {
+            let arr_len = blob.len();
+            start
+                .checked_abs()
+                .map_or(0, |n| arr_len - (n as usize).min(arr_len))
+        } else if start as usize >= blob.len() {
+            return Blob::new();
+        } else {
+            start as usize
+        };
+
+        let len = if len <= 0 {
+            0
+        } else if len as usize > blob.len() - start {
+            blob.len() - start
+        } else {
+            len as usize
+        };
+
+        if len == 0 {
+            Blob::new()
+        } else {
+            blob[start..start + len].to_vec()
+        }
+    }
+    #[rhai_fn(name = "extract")]
+    pub fn extract_tail(blob: &mut Blob, start: INT) -> Blob {
+        if blob.is_empty() {
+            return Blob::new();
+        }
+
+        let start = if start < 0 {
+            let arr_len = blob.len();
+            start
+                .checked_abs()
+                .map_or(0, |n| arr_len - (n as usize).min(arr_len))
+        } else if start as usize >= blob.len() {
+            return Blob::new();
+        } else {
+            start as usize
+        };
+
+        blob[start..].to_vec()
+    }
+    #[rhai_fn(name = "split")]
+    pub fn split_at(blob: &mut Blob, start: INT) -> Blob {
+        if blob.is_empty() {
+            Blob::new()
+        } else if start < 0 {
+            if let Some(n) = start.checked_abs() {
+                if n as usize > blob.len() {
+                    mem::take(blob)
+                } else {
+                    let mut result = Blob::new();
+                    result.extend(blob.drain(blob.len() - n as usize..));
+                    result
+                }
+            } else {
+                mem::take(blob)
+            }
+        } else if start as usize >= blob.len() {
+            Blob::new()
+        } else {
+            let mut result = Blob::new();
+            result.extend(blob.drain(start as usize..));
+            result
+        }
+    }
+    pub fn drain(blob: &mut Blob, start: INT, len: INT) -> Blob {
+        if blob.is_empty() || len <= 0 {
+            return Blob::new();
+        }
+
+        let start = if start < 0 {
+            let arr_len = blob.len();
+            start
+                .checked_abs()
+                .map_or(0, |n| arr_len - (n as usize).min(arr_len))
+        } else if start as usize >= blob.len() {
+            return Blob::new();
+        } else {
+            start as usize
+        };
+
+        let len = if len <= 0 {
+            0
+        } else if len as usize > blob.len() - start {
+            blob.len() - start
+        } else {
+            len as usize
+        };
+
+        blob.drain(start..start + len).collect()
+    }
+    pub fn retain(blob: &mut Blob, start: INT, len: INT) -> Blob {
+        if blob.is_empty() || len <= 0 {
+            return Blob::new();
+        }
+
+        let start = if start < 0 {
+            let arr_len = blob.len();
+            start
+                .checked_abs()
+                .map_or(0, |n| arr_len - (n as usize).min(arr_len))
+        } else if start as usize >= blob.len() {
+            return mem::take(blob);
+        } else {
+            start as usize
+        };
+
+        let len = if len < 0 {
+            0
+        } else if len as usize > blob.len() - start {
+            blob.len() - start
+        } else {
+            len as usize
+        };
+
+        let mut drained: Blob = blob.drain(..start).collect();
+        drained.extend(blob.drain(len..));
+
+        drained
+    }
+    #[rhai_fn(name = "==", pure)]
+    pub fn equals(blob1: &mut Blob, blob2: Blob) -> bool {
+        if blob1.len() != blob2.len() {
+            false
+        } else if blob1.is_empty() {
+            true
+        } else {
+            blob1.iter().zip(blob2.iter()).all(|(&v1, &v2)| v1 == v2)
+        }
+    }
+    #[rhai_fn(name = "!=", pure)]
+    pub fn not_equals(blob1: &mut Blob, blob2: Blob) -> bool {
+        !equals(blob1, blob2)
+    }
+}

src/packages/fn_basic.rs

@@ -90,7 +90,7 @@ fn collect_fn_metadata(ctx: NativeCallContext) -> crate::Array {
     .map(|&s| s.into())
     .collect();
 
-    let mut list = ctx.iter_namespaces().flat_map(Module::iter_script_fn).fold(
+    let mut _list = ctx.iter_namespaces().flat_map(Module::iter_script_fn).fold(
         Array::new(),
         |mut list, (_, _, _, _, f)| {
             list.push(make_metadata(&dict, None, f).into());
@@ -122,8 +122,8 @@ fn collect_fn_metadata(ctx: NativeCallContext) -> crate::Array {
         }
 
         ctx.iter_imports_raw()
-            .for_each(|(ns, m)| scan_module(&mut list, &dict, ns.clone(), m.as_ref()));
+            .for_each(|(ns, m)| scan_module(&mut _list, &dict, ns.clone(), m.as_ref()));
     }
 
-    list
+    _list
 }

src/packages/mod.rs

@@ -4,6 +4,7 @@ use crate::{Module, Shared};
 
 pub(crate) mod arithmetic;
 mod array_basic;
+mod blob_basic;
 mod fn_basic;
 mod iter_basic;
 mod lang_core;
@@ -19,6 +20,8 @@ mod time_basic;
 pub use arithmetic::ArithmeticPackage;
 #[cfg(not(feature = "no_index"))]
 pub use array_basic::BasicArrayPackage;
+#[cfg(not(feature = "no_index"))]
+pub use blob_basic::BasicBlobPackage;
 pub use fn_basic::BasicFnPackage;
 pub use iter_basic::BasicIteratorPackage;
 pub use logic::LogicPackage;

src/packages/pkg_std.rs

@@ -1,5 +1,7 @@
 #[cfg(not(feature = "no_index"))]
 use super::array_basic::BasicArrayPackage;
+#[cfg(not(feature = "no_index"))]
+use super::blob_basic::BasicBlobPackage;
 #[cfg(not(feature = "no_object"))]
 use super::map_basic::BasicMapPackage;
 use super::math_basic::BasicMathPackage;
@@ -18,7 +20,10 @@ def_package!(crate:StandardPackage:"_Standard_ package containing all built-in f
     CorePackage::init(lib);
     BasicMathPackage::init(lib);
     #[cfg(not(feature = "no_index"))]
-    BasicArrayPackage::init(lib);
+    {
+        BasicArrayPackage::init(lib);
+        BasicBlobPackage::init(lib);
+    }
     #[cfg(not(feature = "no_object"))]
     BasicMapPackage::init(lib);
     #[cfg(not(feature = "no_std"))]

src/packages/string_more.rs

@@ -469,7 +469,6 @@ mod string_functions {
         if len <= 0 {
             return Ok(());
         }
-
         let _ctx = ctx;
 
         // Check if string will be over max size limit
@@ -514,7 +513,6 @@ mod string_functions {
         if len <= 0 {
             return Ok(());
         }
-
         let _ctx = ctx;
 
         // Check if string will be over max size limit

src/packages/time_basic.rs

@@ -3,8 +3,6 @@
 use super::{arithmetic::make_err as make_arithmetic_err, math_basic::MAX_INT};
 use crate::plugin::*;
 use crate::{def_package, Dynamic, EvalAltResult, INT};
-#[cfg(feature = "no_std")]
-use std::prelude::v1::*;
 
 #[cfg(not(feature = "no_float"))]
 use crate::FLOAT;

src/parser.rs

@@ -1,5 +1,6 @@
 //! Main module defining the lexer and parser.
 
+use crate::api::options::LanguageOptions;
 use crate::ast::{
     BinaryExpr, CustomExpr, Expr, FnCallExpr, FnCallHashes, Ident, OpAssignment, ScriptFnDef, Stmt,
     StmtBlock, AST_OPTION_FLAGS::*,
@@ -23,6 +24,7 @@ use std::{
     collections::BTreeMap,
     hash::{Hash, Hasher},
     num::{NonZeroU8, NonZeroUsize},
+    ops::AddAssign,
 };
 
 #[cfg(not(feature = "no_float"))]
@@ -51,34 +53,29 @@ const NEVER_ENDS: &str = "`TokenStream` never ends";
 /// collection of strings and returns shared instances, only creating a new string when it is not
 /// yet interned.
 #[derive(Debug, Clone, Hash)]
-pub struct IdentifierBuilder(
+pub struct IdentifierBuilder();
-    #[cfg(feature = "no_smartstring")] std::collections::BTreeSet<Identifier>,
-);
 
 impl IdentifierBuilder {
-    /// Create a new IdentifierBuilder.
+    /// Create a new [`IdentifierBuilder`].
     #[inline]
     #[must_use]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
-        Self(
+        Self()
-            #[cfg(feature = "no_smartstring")]
-            std::collections::BTreeSet::new(),
-        )
     }
     /// Get an identifier from a text string.
     #[inline]
     #[must_use]
     pub fn get(&mut self, text: impl AsRef<str> + Into<Identifier>) -> Identifier {
-        #[cfg(not(feature = "no_smartstring"))]
+        text.into()
-        return text.into();
-
-        #[cfg(feature = "no_smartstring")]
-        return self.0.get(text.as_ref()).cloned().unwrap_or_else(|| {
-            let s: Identifier = text.into();
-            self.0.insert(s.clone());
-            s
-        });
     }
+    /// Merge another [`IdentifierBuilder`] into this.
+    #[inline(always)]
+    pub fn merge(&mut self, _other: &Self) {}
+}
+
+impl AddAssign for IdentifierBuilder {
+    #[inline(always)]
+    fn add_assign(&mut self, _rhs: Self) {}
 }
 
 /// _(internals)_ A type that encapsulates the current state of the parser.
@@ -134,10 +131,10 @@ impl<'e> ParseState<'e> {
             #[cfg(not(feature = "no_closure"))]
             allow_capture: true,
             interned_strings: IdentifierBuilder::new(),
-            stack: StaticVec::new(),
+            stack: StaticVec::new_const(),
             entry_stack_len: 0,
             #[cfg(not(feature = "no_module"))]
-            modules: StaticVec::new(),
+            modules: StaticVec::new_const(),
         }
     }
 
@@ -150,7 +147,9 @@ impl<'e> ParseState<'e> {
     ///
     /// Return `None` when the variable name is not found in the `stack`.
     #[inline]
-    pub fn access_var(&mut self, name: &str, pos: Position) -> Option<NonZeroUsize> {
+    #[must_use]
+    pub fn access_var(&mut self, name: impl AsRef<str>, pos: Position) -> Option<NonZeroUsize> {
+        let name = name.as_ref();
         let mut barrier = false;
         let _pos = pos;
 
@@ -199,7 +198,9 @@ impl<'e> ParseState<'e> {
     #[cfg(not(feature = "no_module"))]
     #[inline]
     #[must_use]
-    pub fn find_module(&self, name: &str) -> Option<NonZeroUsize> {
+    pub fn find_module(&self, name: impl AsRef<str>) -> Option<NonZeroUsize> {
+        let name = name.as_ref();
+
         self.modules
             .iter()
             .rev()
@@ -224,14 +225,24 @@ struct ParseSettings {
     /// Is the construct being parsed located at global level?
     is_global: bool,
     /// Is the construct being parsed located at function definition level?
+    #[cfg(not(feature = "no_function"))]
     is_function_scope: bool,
+    /// Is the construct being parsed located inside a closure?
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(not(feature = "no_closure"))]
+    is_closure: bool,
     /// Is the current position inside a loop?
     is_breakable: bool,
+    /// Default language options.
+    default_options: LanguageOptions,
+    /// Is strict variables mode enabled?
+    strict_var: bool,
     /// Is anonymous function allowed?
+    #[cfg(not(feature = "no_function"))]
     allow_anonymous_fn: bool,
-    /// Is if-expression allowed?
+    /// Is `if`-expression allowed?
     allow_if_expr: bool,
-    /// Is switch expression allowed?
+    /// Is `switch` expression allowed?
     allow_switch_expr: bool,
     /// Is statement-expression allowed?
     allow_stmt_expr: bool,
@@ -334,7 +345,10 @@ impl Expr {
 
 /// Make sure that the next expression is not a statement expression (i.e. wrapped in `{}`).
 #[inline]
-fn ensure_not_statement_expr(input: &mut TokenStream, type_name: &str) -> Result<(), ParseError> {
+fn ensure_not_statement_expr(
+    input: &mut TokenStream,
+    type_name: impl ToString,
+) -> Result<(), ParseError> {
     match input.peek().expect(NEVER_ENDS) {
         (Token::LeftBrace, pos) => Err(PERR::ExprExpected(type_name.to_string()).into_err(*pos)),
         _ => Ok(()),
@@ -465,7 +479,7 @@ fn parse_fn_call(
     let (token, token_pos) = input.peek().expect(NEVER_ENDS);
 
     let mut namespace = namespace;
-    let mut args = StaticVec::new();
+    let mut args = StaticVec::new_const();
 
     match token {
         // id( <EOF>
@@ -482,15 +496,28 @@ fn parse_fn_call(
         Token::RightParen => {
             eat_token(input, Token::RightParen);
 
-            let hash = namespace.as_mut().map_or_else(
+            let hash = if let Some(modules) = namespace.as_mut() {
-                || calc_fn_hash(&id, 0),
+                #[cfg(not(feature = "no_module"))]
-                |modules| {
+                {
-                    #[cfg(not(feature = "no_module"))]
+                    let index = state.find_module(&modules[0].name);
-                    modules.set_index(state.find_module(&modules[0].name));
 
-                    calc_qualified_fn_hash(modules.iter().map(|m| m.name.as_str()), &id, 0)
+                    #[cfg(not(feature = "no_function"))]
-                },
+                    let relax = settings.is_function_scope;
-            );
+                    #[cfg(feature = "no_function")]
+                    let relax = false;
+
+                    if !relax && settings.strict_var && index.is_none() {
+                        return Err(ParseErrorType::ModuleUndefined(modules[0].name.to_string())
+                            .into_err(modules[0].pos));
+                    }
+
+                    modules.set_index(index);
+                }
+
+                calc_qualified_fn_hash(modules.iter().map(|m| m.name.as_str()), &id, 0)
+            } else {
+                calc_fn_hash(&id, 0)
+            };
 
             let hashes = if is_valid_function_name(&id) {
                 hash.into()
@@ -528,19 +555,30 @@ fn parse_fn_call(
             (Token::RightParen, _) => {
                 eat_token(input, Token::RightParen);
 
-                let hash = namespace.as_mut().map_or_else(
+                let hash = if let Some(modules) = namespace.as_mut() {
-                    || calc_fn_hash(&id, args.len()),
+                    #[cfg(not(feature = "no_module"))]
-                    |modules| {
+                    {
-                        #[cfg(not(feature = "no_module"))]
+                        let index = state.find_module(&modules[0].name);
-                        modules.set_index(state.find_module(&modules[0].name));
 
-                        calc_qualified_fn_hash(
+                        #[cfg(not(feature = "no_function"))]
-                            modules.iter().map(|m| m.name.as_str()),
+                        let relax = settings.is_function_scope;
-                            &id,
+                        #[cfg(feature = "no_function")]
-                            args.len(),
+                        let relax = false;
-                        )
+
-                    },
+                        if !relax && settings.strict_var && index.is_none() {
-                );
+                            return Err(ParseErrorType::ModuleUndefined(
+                                modules[0].name.to_string(),
+                            )
+                            .into_err(modules[0].pos));
+                        }
+
+                        modules.set_index(index);
+                    }
+
+                    calc_qualified_fn_hash(modules.iter().map(|m| m.name.as_str()), &id, args.len())
+                } else {
+                    calc_fn_hash(&id, args.len())
+                };
 
                 let hashes = if is_valid_function_name(&id) {
                     hash.into()
@@ -766,7 +804,7 @@ fn parse_array_literal(
     let mut settings = settings;
     settings.pos = eat_token(input, Token::LeftBracket);
 
-    let mut arr = StaticVec::new();
+    let mut arr = StaticVec::new_const();
 
     loop {
         const MISSING_RBRACKET: &str = "to end this array literal";
@@ -1162,24 +1200,42 @@ fn parse_primary(
                 new_state.max_expr_depth = new_state.max_function_expr_depth;
             }
 
-            let settings = ParseSettings {
+            let new_settings = ParseSettings {
-                allow_if_expr: true,
+                allow_if_expr: settings.default_options.allow_if_expr,
-                allow_switch_expr: true,
+                allow_switch_expr: settings.default_options.allow_switch_expr,
-                allow_stmt_expr: true,
+                allow_stmt_expr: settings.default_options.allow_stmt_expr,
-                allow_anonymous_fn: true,
+                allow_anonymous_fn: settings.default_options.allow_anonymous_fn,
+                strict_var: if cfg!(feature = "no_closure") {
+                    settings.strict_var
+                } else {
+                    // A capturing closure can access variables not defined locally
+                    false
+                },
                 is_global: false,
                 is_function_scope: true,
+                #[cfg(not(feature = "no_closure"))]
+                is_closure: true,
                 is_breakable: false,
                 level: 0,
-                pos: settings.pos,
+                ..settings
             };
 
-            let (expr, func) = parse_anon_fn(input, &mut new_state, lib, settings)?;
+            let (expr, func) = parse_anon_fn(input, &mut new_state, lib, new_settings)?;
 
             #[cfg(not(feature = "no_closure"))]
-            new_state.external_vars.iter().for_each(|(closure, &pos)| {
+            new_state.external_vars.iter().try_for_each(
-                state.access_var(closure, pos);
+                |(captured_var, &pos)| -> Result<_, ParseError> {
-            });
+                    let index = state.access_var(captured_var, pos);
+
+                    if !settings.is_closure && settings.strict_var && index.is_none() {
+                        // If the parent scope is not inside another capturing closure
+                        Err(ParseErrorType::VariableUndefined(captured_var.to_string())
+                            .into_err(pos))
+                    } else {
+                        Ok(())
+                    }
+                },
+            )?;
 
             let hash_script = calc_fn_hash(&func.name, func.params.len());
             lib.insert(hash_script, func.into());
@@ -1282,6 +1338,13 @@ fn parse_primary(
                 // Normal variable access
                 _ => {
                     let index = state.access_var(&s, settings.pos);
+
+                    if settings.strict_var && index.is_none() {
+                        return Err(
+                            ParseErrorType::VariableUndefined(s.to_string()).into_err(settings.pos)
+                        );
+                    }
+
                     let short_index = index.and_then(|x| {
                         if x.get() <= u8::MAX as usize {
                             NonZeroU8::new(x.get() as u8)
@@ -1313,6 +1376,7 @@ fn parse_primary(
                     (None, None, state.get_identifier(s)).into(),
                 ),
                 // Access to `this` as a variable is OK within a function scope
+                #[cfg(not(feature = "no_function"))]
                 _ if &*s == KEYWORD_THIS && settings.is_function_scope => Expr::Variable(
                     None,
                     settings.pos,
@@ -1454,15 +1518,26 @@ fn parse_primary(
         _ => None,
     };
 
-    if let Some(x) = namespaced_variable {
+    if let Some((_, Some((namespace, hash)), name)) = namespaced_variable {
-        match x {
+        *hash = calc_qualified_var_hash(namespace.iter().map(|v| v.name.as_str()), name);
-            (_, Some((namespace, hash)), name) => {
-                *hash = calc_qualified_var_hash(namespace.iter().map(|v| v.name.as_str()), name);
 
-                #[cfg(not(feature = "no_module"))]
+        #[cfg(not(feature = "no_module"))]
-                namespace.set_index(state.find_module(&namespace[0].name));
+        {
+            let index = state.find_module(&namespace[0].name);
+
+            #[cfg(not(feature = "no_function"))]
+            let relax = settings.is_function_scope;
+            #[cfg(feature = "no_function")]
+            let relax = false;
+
+            if !relax && settings.strict_var && index.is_none() {
+                return Err(
+                    ParseErrorType::ModuleUndefined(namespace[0].name.to_string())
+                        .into_err(namespace[0].pos),
+                );
             }
-            _ => unreachable!("expecting namespace-qualified variable access"),
+
+            namespace.set_index(index);
         }
     }
 
@@ -1510,7 +1585,7 @@ fn parse_unary(
 
                 // Call negative function
                 expr => {
-                    let mut args = StaticVec::new();
+                    let mut args = StaticVec::new_const();
                     args.push(expr);
                     args.shrink_to_fit();
 
@@ -1536,7 +1611,7 @@ fn parse_unary(
 
                 // Call plus function
                 expr => {
-                    let mut args = StaticVec::new();
+                    let mut args = StaticVec::new_const();
                     args.push(expr);
                     args.shrink_to_fit();
 
@@ -1553,7 +1628,7 @@ fn parse_unary(
         // !expr
         Token::Bang => {
             let pos = eat_token(input, Token::Bang);
-            let mut args = StaticVec::new();
+            let mut args = StaticVec::new_const();
             args.push(parse_unary(input, state, lib, settings.level_up())?);
             args.shrink_to_fit();
 
@@ -1900,7 +1975,7 @@ fn parse_binary_op(
             ..Default::default()
         };
 
-        let mut args = StaticVec::new();
+        let mut args = StaticVec::new_const();
         args.push(root);
         args.push(rhs);
         args.shrink_to_fit();
@@ -2000,21 +2075,21 @@ fn parse_custom_syntax(
     state: &mut ParseState,
     lib: &mut FunctionsLib,
     settings: ParseSettings,
-    key: &str,
+    key: impl Into<ImmutableString>,
     syntax: &CustomSyntax,
     pos: Position,
 ) -> Result<Expr, ParseError> {
     let mut settings = settings;
     let mut inputs = StaticVec::<Expr>::new();
-    let mut segments = StaticVec::new();
+    let mut segments = StaticVec::new_const();
-    let mut tokens = StaticVec::new();
+    let mut tokens = StaticVec::new_const();
 
     // Adjust the variables stack
     if syntax.scope_may_be_changed {
         // Add a barrier variable to the stack so earlier variables will not be matched.
         // Variable searches stop at the first barrier.
-        let empty = state.get_identifier(SCOPE_SEARCH_BARRIER_MARKER);
+        let marker = state.get_identifier(SCOPE_SEARCH_BARRIER_MARKER);
-        state.stack.push((empty, AccessMode::ReadWrite));
+        state.stack.push((marker, AccessMode::ReadWrite));
     }
 
     let parse_func = syntax.parse.as_ref();
@@ -2789,16 +2864,20 @@ fn parse_stmt(
                         new_state.max_expr_depth = new_state.max_function_expr_depth;
                     }
 
-                    let settings = ParseSettings {
+                    let new_settings = ParseSettings {
-                        allow_if_expr: true,
+                        allow_if_expr: settings.default_options.allow_if_expr,
-                        allow_switch_expr: true,
+                        allow_switch_expr: settings.default_options.allow_switch_expr,
-                        allow_stmt_expr: true,
+                        allow_stmt_expr: settings.default_options.allow_stmt_expr,
-                        allow_anonymous_fn: true,
+                        allow_anonymous_fn: settings.default_options.allow_anonymous_fn,
+                        strict_var: settings.strict_var,
                         is_global: false,
                         is_function_scope: true,
+                        #[cfg(not(feature = "no_closure"))]
+                        is_closure: false,
                         is_breakable: false,
                         level: 0,
                         pos,
+                        ..settings
                     };
 
                     let func = parse_fn(
@@ -2806,7 +2885,7 @@ fn parse_stmt(
                         &mut new_state,
                         lib,
                         access,
-                        settings,
+                        new_settings,
                         #[cfg(not(feature = "no_function"))]
                         #[cfg(feature = "metadata")]
                         comments,
@@ -2837,19 +2916,27 @@ fn parse_stmt(
 
         Token::If => parse_if(input, state, lib, settings.level_up()),
         Token::Switch => parse_switch(input, state, lib, settings.level_up()),
-        Token::While | Token::Loop => parse_while_loop(input, state, lib, settings.level_up()),
+        Token::While | Token::Loop if settings.default_options.allow_loop => {
-        Token::Do => parse_do(input, state, lib, settings.level_up()),
+            parse_while_loop(input, state, lib, settings.level_up())
-        Token::For => parse_for(input, state, lib, settings.level_up()),
+        }
+        Token::Do if settings.default_options.allow_loop => {
+            parse_do(input, state, lib, settings.level_up())
+        }
+        Token::For if settings.default_options.allow_loop => {
+            parse_for(input, state, lib, settings.level_up())
+        }
 
-        Token::Continue if settings.is_breakable => {
+        Token::Continue if settings.default_options.allow_loop && settings.is_breakable => {
             let pos = eat_token(input, Token::Continue);
             Ok(Stmt::BreakLoop(AST_OPTION_NONE, pos))
         }
-        Token::Break if settings.is_breakable => {
+        Token::Break if settings.default_options.allow_loop && settings.is_breakable => {
             let pos = eat_token(input, Token::Break);
             Ok(Stmt::BreakLoop(AST_OPTION_BREAK_OUT, pos))
         }
-        Token::Continue | Token::Break => Err(PERR::LoopBreak.into_err(token_pos)),
+        Token::Continue | Token::Break if settings.default_options.allow_loop => {
+            Err(PERR::LoopBreak.into_err(token_pos))
+        }
 
         Token::Return | Token::Throw => {
             let (return_type, token_pos) = input
@@ -2992,7 +3079,7 @@ fn parse_fn(
         (_, pos) => return Err(PERR::FnMissingParams(name.to_string()).into_err(*pos)),
     };
 
-    let mut params = StaticVec::new();
+    let mut params = StaticVec::new_const();
 
     if !match_token(input, Token::RightParen).0 {
         let sep_err = format!("to separate the parameters of function '{}'", name);
@@ -3119,7 +3206,7 @@ fn parse_anon_fn(
     settings.ensure_level_within_max_limit(state.max_expr_depth)?;
 
     let mut settings = settings;
-    let mut params_list = StaticVec::new();
+    let mut params_list = StaticVec::new_const();
 
     if input.next().expect(NEVER_ENDS).0 != Token::Or && !match_token(input, Token::Pipe).0 {
         loop {
@@ -3205,7 +3292,7 @@ fn parse_anon_fn(
         comments: None,
     };
 
-    let fn_ptr = crate::FnPtr::new_unchecked(fn_name, StaticVec::new());
+    let fn_ptr = crate::FnPtr::new_unchecked(fn_name, StaticVec::new_const());
     let expr = Expr::DynamicConstant(Box::new(fn_ptr.into()), settings.pos);
 
     #[cfg(not(feature = "no_closure"))]
@@ -3227,12 +3314,19 @@ impl Engine {
         let mut functions = BTreeMap::new();
 
         let settings = ParseSettings {
+            default_options: self.options,
             allow_if_expr: false,
             allow_switch_expr: false,
             allow_stmt_expr: false,
+            #[cfg(not(feature = "no_function"))]
             allow_anonymous_fn: false,
+            strict_var: self.options.strict_var,
             is_global: true,
+            #[cfg(not(feature = "no_function"))]
             is_function_scope: false,
+            #[cfg(not(feature = "no_function"))]
+            #[cfg(not(feature = "no_closure"))]
+            is_closure: false,
             is_breakable: false,
             level: 0,
             pos: Position::NONE,
@@ -3249,7 +3343,7 @@ impl Engine {
             }
         }
 
-        let mut statements = StaticVec::new();
+        let mut statements = StaticVec::new_const();
         statements.push(Stmt::Expr(expr));
 
         #[cfg(not(feature = "no_optimize"))]
@@ -3257,12 +3351,17 @@ impl Engine {
             self,
             _scope,
             statements,
-            StaticVec::new(),
+            #[cfg(not(feature = "no_function"))]
+            StaticVec::new_const(),
             optimization_level,
         ));
 
         #[cfg(feature = "no_optimize")]
-        return Ok(AST::new(statements, crate::Module::new()));
+        return Ok(AST::new(
+            statements,
+            #[cfg(not(feature = "no_function"))]
+            crate::Module::new(),
+        ));
     }
 
     /// Parse the global level statements.
@@ -3271,17 +3370,24 @@ impl Engine {
         input: &mut TokenStream,
         state: &mut ParseState,
     ) -> Result<(StaticVec<Stmt>, StaticVec<Shared<ScriptFnDef>>), ParseError> {
-        let mut statements = StaticVec::new();
+        let mut statements = StaticVec::new_const();
         let mut functions = BTreeMap::new();
 
         while !input.peek().expect(NEVER_ENDS).0.is_eof() {
             let settings = ParseSettings {
-                allow_if_expr: true,
+                default_options: self.options,
-                allow_switch_expr: true,
+                allow_if_expr: self.options.allow_if_expr,
-                allow_stmt_expr: true,
+                allow_switch_expr: self.options.allow_switch_expr,
-                allow_anonymous_fn: true,
+                allow_stmt_expr: self.options.allow_stmt_expr,
+                #[cfg(not(feature = "no_function"))]
+                allow_anonymous_fn: self.options.allow_anonymous_fn,
+                strict_var: self.options.strict_var,
                 is_global: true,
+                #[cfg(not(feature = "no_function"))]
                 is_function_scope: false,
+                #[cfg(not(feature = "no_function"))]
+                #[cfg(not(feature = "no_closure"))]
+                is_closure: false,
                 is_breakable: false,
                 level: 0,
                 pos: Position::NONE,
@@ -3342,6 +3448,7 @@ impl Engine {
             self,
             _scope,
             statements,
+            #[cfg(not(feature = "no_function"))]
             _lib,
             optimization_level,
         ));
@@ -3360,6 +3467,10 @@ impl Engine {
 
         #[cfg(feature = "no_optimize")]
         #[cfg(feature = "no_function")]
-        return Ok(AST::new(statements, crate::Module::new()));
+        return Ok(AST::new(
+            statements,
+            #[cfg(not(feature = "no_function"))]
+            crate::Module::new(),
+        ));
     }
 }

src/serde/de.rs

@@ -1,16 +1,15 @@
 //! Implement deserialization support of [`Dynamic`][crate::Dynamic] for [`serde`].
 
-use super::str::StringSliceDeserializer;
 use crate::types::dynamic::Union;
 use crate::{Dynamic, EvalAltResult, ImmutableString, LexError, Position};
-use serde::de::{DeserializeSeed, Error, IntoDeserializer, MapAccess, SeqAccess, Visitor};
+use serde::de::{DeserializeSeed, Error, IntoDeserializer, Visitor};
 use serde::{Deserialize, Deserializer};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 use std::{any::type_name, fmt};
 
 #[cfg(not(feature = "no_index"))]
-use crate::Array;
+use crate::{Array, Blob};
 
 #[cfg(not(feature = "no_object"))]
 use crate::Map;
@@ -153,6 +152,8 @@ impl<'de> Deserializer<'de> for &mut DynamicDeserializer<'de> {
 
             #[cfg(not(feature = "no_index"))]
             Union::Array(_, _, _) => self.deserialize_seq(visitor),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(_, _, _) => self.deserialize_bytes(visitor),
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, _, _) => self.deserialize_map(visitor),
             Union::FnPtr(_, _, _) => self.type_error(),
@@ -355,16 +356,36 @@ impl<'de> Deserializer<'de> for &mut DynamicDeserializer<'de> {
         self.deserialize_str(visitor)
     }
 
-    fn deserialize_bytes<V: Visitor<'de>>(self, _: V) -> Result<V::Value, Box<EvalAltResult>> {
+    fn deserialize_bytes<V: Visitor<'de>>(
-        self.type_error()
+        self,
+        _visitor: V,
+    ) -> Result<V::Value, Box<EvalAltResult>> {
+        #[cfg(not(feature = "no_index"))]
+        return self
+            .value
+            .downcast_ref::<Blob>()
+            .map_or_else(|| self.type_error(), |x| _visitor.visit_bytes(x));
+
+        #[cfg(feature = "no_index")]
+        return self.type_error();
     }
 
-    fn deserialize_byte_buf<V: Visitor<'de>>(self, _: V) -> Result<V::Value, Box<EvalAltResult>> {
+    fn deserialize_byte_buf<V: Visitor<'de>>(
-        self.type_error()
+        self,
+        visitor: V,
+    ) -> Result<V::Value, Box<EvalAltResult>> {
+        self.deserialize_bytes(visitor)
     }
 
-    fn deserialize_option<V: Visitor<'de>>(self, _: V) -> Result<V::Value, Box<EvalAltResult>> {
+    fn deserialize_option<V: Visitor<'de>>(
-        self.type_error()
+        self,
+        visitor: V,
+    ) -> Result<V::Value, Box<EvalAltResult>> {
+        if self.value.is::<()>() {
+            visitor.visit_none()
+        } else {
+            visitor.visit_some(self)
+        }
     }
 
     fn deserialize_unit<V: Visitor<'de>>(self, visitor: V) -> Result<V::Value, Box<EvalAltResult>> {
@@ -393,7 +414,7 @@ impl<'de> Deserializer<'de> for &mut DynamicDeserializer<'de> {
         #[cfg(not(feature = "no_index"))]
         return self.value.downcast_ref::<Array>().map_or_else(
             || self.type_error(),
-            |arr| _visitor.visit_seq(IterateArray::new(arr.iter())),
+            |arr| _visitor.visit_seq(IterateDynamicArray::new(arr.iter())),
         );
 
         #[cfg(feature = "no_index")]
@@ -488,20 +509,24 @@ impl<'de> Deserializer<'de> for &mut DynamicDeserializer<'de> {
 }
 
 /// `SeqAccess` implementation for arrays.
-struct IterateArray<'a, ITER: Iterator<Item = &'a Dynamic>> {
+#[cfg(not(feature = "no_index"))]
+struct IterateDynamicArray<'a, ITER: Iterator<Item = &'a Dynamic>> {
     /// Iterator for a stream of [`Dynamic`][crate::Dynamic] values.
     iter: ITER,
 }
 
 #[cfg(not(feature = "no_index"))]
-impl<'a, ITER: Iterator<Item = &'a Dynamic>> IterateArray<'a, ITER> {
+impl<'a, ITER: Iterator<Item = &'a Dynamic>> IterateDynamicArray<'a, ITER> {
     #[must_use]
     pub fn new(iter: ITER) -> Self {
         Self { iter }
     }
 }
 
-impl<'a: 'de, 'de, ITER: Iterator<Item = &'a Dynamic>> SeqAccess<'de> for IterateArray<'a, ITER> {
+#[cfg(not(feature = "no_index"))]
+impl<'a: 'de, 'de, ITER: Iterator<Item = &'a Dynamic>> serde::de::SeqAccess<'de>
+    for IterateDynamicArray<'a, ITER>
+{
     type Error = Box<EvalAltResult>;
 
     fn next_element_seed<T: DeserializeSeed<'de>>(
@@ -519,6 +544,7 @@ impl<'a: 'de, 'de, ITER: Iterator<Item = &'a Dynamic>> SeqAccess<'de> for Iterat
 }
 
 /// `MapAccess` implementation for maps.
+#[cfg(not(feature = "no_object"))]
 struct IterateMap<'a, KEYS, VALUES>
 where
     KEYS: Iterator<Item = &'a str>,
@@ -542,7 +568,8 @@ where
     }
 }
 
-impl<'a: 'de, 'de, KEYS, VALUES> MapAccess<'de> for IterateMap<'a, KEYS, VALUES>
+#[cfg(not(feature = "no_object"))]
+impl<'a: 'de, 'de, KEYS, VALUES> serde::de::MapAccess<'de> for IterateMap<'a, KEYS, VALUES>
 where
     KEYS: Iterator<Item = &'a str>,
     VALUES: Iterator<Item = &'a Dynamic>,
@@ -557,7 +584,7 @@ where
         match self.keys.next() {
             None => Ok(None),
             Some(item) => seed
-                .deserialize(&mut StringSliceDeserializer::from_str(item))
+                .deserialize(&mut super::str::StringSliceDeserializer::from_str(item))
                 .map(Some),
         }
     }

src/serde/metadata.rs

@@ -272,12 +272,13 @@ impl Engine {
     }
 
     /// Generate a list of all functions in JSON format.
-    /// Available only under the `metadata` feature.
+    /// Exported under the `metadata` feature only.
     ///
     /// Functions from the following sources are included:
     /// 1) Functions registered into the global namespace
     /// 2) Functions in static modules
     /// 3) Functions in global modules (optional)
+    #[inline(always)]
     pub fn gen_fn_metadata_to_json(&self, include_global: bool) -> serde_json::Result<String> {
         self.gen_fn_metadata_with_ast_to_json(&AST::empty(), include_global)
     }

src/serde/ser.rs

@@ -257,11 +257,20 @@ impl Serializer for &mut DynamicSerializer {
     }
 
     fn serialize_str(self, v: &str) -> Result<Self::Ok, Box<EvalAltResult>> {
-        Ok(v.to_string().into())
+        Ok(v.into())
     }
 
-    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Box<EvalAltResult>> {
+    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok, Box<EvalAltResult>> {
-        Ok(Dynamic::from(v.to_vec()))
+        #[cfg(not(feature = "no_index"))]
+        return Ok(Dynamic::from_blob(_v.to_vec()));
+
+        #[cfg(feature = "no_index")]
+        return Err(EvalAltResult::ErrorMismatchDataType(
+            "".into(),
+            "BLOB's are not supported with 'no_index'".into(),
+            Position::NONE,
+        )
+        .into());
     }
 
     fn serialize_none(self) -> Result<Self::Ok, Box<EvalAltResult>> {

src/serde/serialize.rs

@@ -57,6 +57,8 @@ impl Serialize for Dynamic {
 
             #[cfg(not(feature = "no_index"))]
             Union::Array(ref a, _, _) => (**a).serialize(ser),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(ref a, _, _) => (**a).serialize(ser),
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref m, _, _) => {
                 let mut map = ser.serialize_map(Some(m.len()))?;

src/tests.rs

@@ -15,20 +15,15 @@ fn check_struct_sizes() {
 
     assert_eq!(size_of::<Dynamic>(), if PACKED { 8 } else { 16 });
     assert_eq!(size_of::<Option<Dynamic>>(), if PACKED { 8 } else { 16 });
-    #[cfg(not(feature = "no_position"))]
+    assert_eq!(
-    assert_eq!(size_of::<Position>(), 4);
+        size_of::<Position>(),
+        if cfg!(feature = "no_position") { 0 } else { 4 }
+    );
     assert_eq!(size_of::<ast::Expr>(), 16);
     assert_eq!(size_of::<Option<ast::Expr>>(), 16);
     assert_eq!(size_of::<ast::Stmt>(), 32);
     assert_eq!(size_of::<Option<ast::Stmt>>(), 32);
-    assert_eq!(
+    assert_eq!(size_of::<FnPtr>(), 80);
-        size_of::<FnPtr>(),
-        if cfg!(feature = "no_smartstring") {
-            64
-        } else {
-            80
-        }
-    );
     assert_eq!(size_of::<Scope>(), 464);
     assert_eq!(size_of::<LexError>(), 56);
     assert_eq!(

src/tokenizer.rs

@@ -29,10 +29,6 @@ use rust_decimal::Decimal;
 use crate::engine::KEYWORD_IS_DEF_FN;
 
 /// _(internals)_ A type containing commands to control the tokenizer.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Eq, PartialEq, Hash, Copy)]
 pub struct TokenizerControlBlock {
     /// Is the current tokenizer position within an interpolated text string?
@@ -301,10 +297,6 @@ impl AddAssign for Position {
 
 /// _(internals)_ A Rhai language token.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, PartialEq, Clone, Hash)]
 pub enum Token {
     /// An `INT` constant.
@@ -695,9 +687,11 @@ impl Token {
 
     /// Reverse lookup a token from a piece of syntax.
     #[must_use]
-    pub fn lookup_from_syntax(syntax: &str) -> Option<Self> {
+    pub fn lookup_from_syntax(syntax: impl AsRef<str>) -> Option<Self> {
         use Token::*;
 
+        let syntax = syntax.as_ref();
+
         Some(match syntax {
             "{" => LeftBrace,
             "}" => RightBrace,
@@ -770,6 +764,9 @@ impl Token {
             #[cfg(not(feature = "no_function"))]
             "private" => Private,
 
+            #[cfg(feature = "no_function")]
+            "fn" | "private" => Reserved(syntax.into()),
+
             #[cfg(not(feature = "no_module"))]
             "import" => Import,
             #[cfg(not(feature = "no_module"))]
@@ -777,9 +774,6 @@ impl Token {
             #[cfg(not(feature = "no_module"))]
             "as" => As,
 
-            #[cfg(feature = "no_function")]
-            "fn" | "private" => Reserved(syntax.into()),
-
             #[cfg(feature = "no_module")]
             "import" | "export" | "as" => Reserved(syntax.into()),
 
@@ -1000,10 +994,6 @@ impl From<Token> for String {
 
 /// _(internals)_ State of the tokenizer.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct TokenizeState {
     /// Maximum length of a string.
@@ -1020,10 +1010,6 @@ pub struct TokenizeState {
 
 /// _(internals)_ Trait that encapsulates a peekable character input stream.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This trait is volatile and may change.
 pub trait InputStream {
     /// Un-get a character back into the `InputStream`.
     /// The next [`get_next`][InputStream::get_next] or [`peek_next`][InputStream::peek_next]
@@ -1066,10 +1052,6 @@ pub trait InputStream {
 ///
 /// Any time a [`StringConstant`][`Token::StringConstant`] is returned with
 /// `state.is_within_text_terminated_by` set to `Some(_)` is one of the above conditions.
-///
-/// # Volatile API
-///
-/// This function is volatile and may change.
 pub fn parse_string_literal(
     stream: &mut impl InputStream,
     state: &mut TokenizeState,
@@ -1326,10 +1308,6 @@ fn scan_block_comment(
 
 /// _(internals)_ Get the next token from the `stream`.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile API
-///
-/// This function is volatile and may change.
 #[inline]
 #[must_use]
 pub fn get_next_token(
@@ -1364,7 +1342,9 @@ fn is_numeric_digit(c: char) -> bool {
 #[cfg(feature = "metadata")]
 #[inline]
 #[must_use]
-pub fn is_doc_comment(comment: &str) -> bool {
+pub fn is_doc_comment(comment: impl AsRef<str>) -> bool {
+    let comment = comment.as_ref();
+
     (comment.starts_with("///") && !comment.starts_with("////"))
         || (comment.starts_with("/**") && !comment.starts_with("/***"))
 }
@@ -2004,8 +1984,8 @@ fn get_identifier(
 /// Is this keyword allowed as a function?
 #[inline]
 #[must_use]
-pub fn is_keyword_function(name: &str) -> bool {
+pub fn is_keyword_function(name: impl AsRef<str>) -> bool {
-    match name {
+    match name.as_ref() {
         KEYWORD_PRINT | KEYWORD_DEBUG | KEYWORD_TYPE_OF | KEYWORD_EVAL | KEYWORD_FN_PTR
         | KEYWORD_FN_PTR_CALL | KEYWORD_FN_PTR_CURRY | KEYWORD_IS_DEF_VAR => true,
 
@@ -2037,8 +2017,8 @@ pub fn is_valid_identifier(name: impl Iterator<Item = char>) -> bool {
 /// Is a text string a valid scripted function name?
 #[inline(always)]
 #[must_use]
-pub fn is_valid_function_name(name: &str) -> bool {
+pub fn is_valid_function_name(name: impl AsRef<str>) -> bool {
-    is_valid_identifier(name.chars())
+    is_valid_identifier(name.as_ref().chars())
 }
 
 /// Is a character valid to start an identifier?
@@ -2135,10 +2115,6 @@ impl InputStream for MultiInputsStream<'_> {
 
 /// _(internals)_ An iterator on a [`Token`] stream.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 pub struct TokenIterator<'a> {
     /// Reference to the scripting `Engine`.
     pub engine: &'a Engine,
@@ -2265,7 +2241,7 @@ impl Engine {
     #[must_use]
     pub fn lex<'a>(
         &'a self,
-        input: impl IntoIterator<Item = &'a &'a str>,
+        input: impl IntoIterator<Item = &'a (impl AsRef<str> + 'a)>,
     ) -> (TokenIterator<'a>, TokenizerControl) {
         self.lex_raw(input, None)
     }
@@ -2276,7 +2252,7 @@ impl Engine {
     #[must_use]
     pub fn lex_with_map<'a>(
         &'a self,
-        input: impl IntoIterator<Item = &'a &'a str>,
+        input: impl IntoIterator<Item = &'a (impl AsRef<str> + 'a)>,
         token_mapper: &'a OnParseTokenCallback,
     ) -> (TokenIterator<'a>, TokenizerControl) {
         self.lex_raw(input, Some(token_mapper))
@@ -2286,7 +2262,7 @@ impl Engine {
     #[must_use]
     pub(crate) fn lex_raw<'a>(
         &'a self,
-        input: impl IntoIterator<Item = &'a &'a str>,
+        input: impl IntoIterator<Item = &'a (impl AsRef<str> + 'a)>,
         token_mapper: Option<&'a OnParseTokenCallback>,
     ) -> (TokenIterator<'a>, TokenizerControl) {
         let buffer: TokenizerControl = Cell::new(TokenizerControlBlock::new()).into();
@@ -2309,7 +2285,10 @@ impl Engine {
                 tokenizer_control: buffer,
                 stream: MultiInputsStream {
                     buf: None,
-                    streams: input.into_iter().map(|s| s.chars().peekable()).collect(),
+                    streams: input
+                        .into_iter()
+                        .map(|s| s.as_ref().chars().peekable())
+                        .collect(),
                     index: 0,
                 },
                 token_mapper,

src/types/dynamic.rs

@@ -20,7 +20,7 @@ use crate::{ast::FloatWrapper, FLOAT};
 use rust_decimal::Decimal;
 
 #[cfg(not(feature = "no_index"))]
-use crate::Array;
+use crate::{Array, Blob};
 
 #[cfg(not(feature = "no_object"))]
 use crate::Map;
@@ -200,6 +200,11 @@ pub enum Union {
     /// Not available under `no_index`.
     #[cfg(not(feature = "no_index"))]
     Array(Box<Array>, Tag, AccessMode),
+    /// An blob (byte array).
+    ///
+    /// Not available under `no_index`.
+    #[cfg(not(feature = "no_index"))]
+    Blob(Box<Blob>, Tag, AccessMode),
     /// An object map value.
     ///
     /// Not available under `no_object`.
@@ -229,10 +234,6 @@ pub enum Union {
 ///
 /// This type provides transparent interoperability between normal [`Dynamic`] and shared
 /// [`Dynamic`] values.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug)]
 pub struct DynamicReadLock<'d, T: Clone>(DynamicReadLockInner<'d, T>);
 
@@ -270,10 +271,6 @@ impl<'d, T: Any + Clone> Deref for DynamicReadLock<'d, T> {
 ///
 /// This type provides transparent interoperability between normal [`Dynamic`] and shared
 /// [`Dynamic`] values.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug)]
 pub struct DynamicWriteLock<'d, T: Clone>(DynamicWriteLockInner<'d, T>);
 
@@ -332,7 +329,7 @@ impl Dynamic {
             #[cfg(feature = "decimal")]
             Union::Decimal(_, tag, _) => tag,
             #[cfg(not(feature = "no_index"))]
-            Union::Array(_, tag, _) => tag,
+            Union::Array(_, tag, _) | Union::Blob(_, tag, _) => tag,
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, tag, _) => tag,
             #[cfg(not(feature = "no_std"))]
@@ -357,7 +354,7 @@ impl Dynamic {
             #[cfg(feature = "decimal")]
             Union::Decimal(_, ref mut tag, _) => *tag = value,
             #[cfg(not(feature = "no_index"))]
-            Union::Array(_, ref mut tag, _) => *tag = value,
+            Union::Array(_, ref mut tag, _) | Union::Blob(_, ref mut tag, _) => *tag = value,
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, ref mut tag, _) => *tag = value,
             #[cfg(not(feature = "no_std"))]
@@ -419,6 +416,8 @@ impl Dynamic {
             Union::Decimal(_, _, _) => TypeId::of::<Decimal>(),
             #[cfg(not(feature = "no_index"))]
             Union::Array(_, _, _) => TypeId::of::<Array>(),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(_, _, _) => TypeId::of::<Blob>(),
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, _, _) => TypeId::of::<Map>(),
             Union::FnPtr(_, _, _) => TypeId::of::<FnPtr>(),
@@ -456,6 +455,8 @@ impl Dynamic {
             Union::Decimal(_, _, _) => "decimal",
             #[cfg(not(feature = "no_index"))]
             Union::Array(_, _, _) => "array",
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(_, _, _) => "blob",
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, _, _) => "map",
             Union::FnPtr(_, _, _) => "Fn",
@@ -498,6 +499,8 @@ impl Hash for Dynamic {
             Union::Decimal(ref d, _, _) => d.hash(state),
             #[cfg(not(feature = "no_index"))]
             Union::Array(ref a, _, _) => a.as_ref().hash(state),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(ref a, _, _) => a.as_ref().hash(state),
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref m, _, _) => m.as_ref().hash(state),
             Union::FnPtr(ref f, _, _) => f.hash(state),
@@ -586,6 +589,10 @@ pub(crate) fn map_std_type_name(name: &str) -> &str {
     if name == type_name::<Array>() {
         return "array";
     }
+    #[cfg(not(feature = "no_index"))]
+    if name == type_name::<Blob>() {
+        return "blob";
+    }
     #[cfg(not(feature = "no_object"))]
     if name == type_name::<Map>() {
         return "map";
@@ -612,6 +619,8 @@ impl fmt::Display for Dynamic {
             Union::Decimal(ref value, _, _) => fmt::Display::fmt(value, f),
             #[cfg(not(feature = "no_index"))]
             Union::Array(ref value, _, _) => fmt::Debug::fmt(value, f),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(ref value, _, _) => fmt::Debug::fmt(value, f),
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref value, _, _) => {
                 f.write_str("#")?;
@@ -692,6 +701,8 @@ impl fmt::Debug for Dynamic {
             Union::Decimal(ref value, _, _) => fmt::Debug::fmt(value, f),
             #[cfg(not(feature = "no_index"))]
             Union::Array(ref value, _, _) => fmt::Debug::fmt(value, f),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(ref value, _, _) => fmt::Debug::fmt(value, f),
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref value, _, _) => {
                 f.write_str("#")?;
@@ -781,6 +792,8 @@ impl Clone for Dynamic {
             }
             #[cfg(not(feature = "no_index"))]
             Union::Array(ref value, tag, _) => Self(Union::Array(value.clone(), tag, ReadWrite)),
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(ref value, tag, _) => Self(Union::Blob(value.clone(), tag, ReadWrite)),
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref value, tag, _) => Self(Union::Map(value.clone(), tag, ReadWrite)),
             Union::FnPtr(ref value, tag, _) => Self(Union::FnPtr(value.clone(), tag, ReadWrite)),
@@ -972,7 +985,7 @@ impl Dynamic {
             #[cfg(feature = "decimal")]
             Union::Decimal(_, _, access) => access,
             #[cfg(not(feature = "no_index"))]
-            Union::Array(_, _, access) => access,
+            Union::Array(_, _, access) | Union::Blob(_, _, access) => access,
             #[cfg(not(feature = "no_object"))]
             Union::Map(_, _, access) => access,
             #[cfg(not(feature = "no_std"))]
@@ -1003,6 +1016,8 @@ impl Dynamic {
                     v.set_access_mode(typ);
                 });
             }
+            #[cfg(not(feature = "no_index"))]
+            Union::Blob(_, _, ref mut access) => *access = typ,
             #[cfg(not(feature = "no_object"))]
             Union::Map(ref mut m, _, ref mut access) => {
                 *access = typ;
@@ -1166,6 +1181,13 @@ impl Dynamic {
                 Err(value) => value,
             };
         }
+        #[cfg(not(feature = "no_index"))]
+        {
+            value = match unsafe_try_cast::<_, Blob>(value) {
+                Ok(blob) => return Self(Union::Blob(Box::new(blob), DEFAULT_TAG_VALUE, ReadWrite)),
+                Err(value) => value,
+            };
+        }
 
         #[cfg(not(feature = "no_object"))]
         {
@@ -1327,6 +1349,14 @@ impl Dynamic {
             };
         }
 
+        #[cfg(not(feature = "no_index"))]
+        if TypeId::of::<T>() == TypeId::of::<Blob>() {
+            return match self.0 {
+                Union::Blob(value, _, _) => unsafe_cast_box::<_, T>(value).ok().map(|v| *v),
+                _ => None,
+            };
+        }
+
         #[cfg(not(feature = "no_object"))]
         if TypeId::of::<T>() == TypeId::of::<Map>() {
             return match self.0 {
@@ -1660,6 +1690,13 @@ impl Dynamic {
                 _ => None,
             };
         }
+        #[cfg(not(feature = "no_index"))]
+        if TypeId::of::<T>() == TypeId::of::<Blob>() {
+            return match self.0 {
+                Union::Blob(ref value, _, _) => value.as_ref().as_any().downcast_ref::<T>(),
+                _ => None,
+            };
+        }
         #[cfg(not(feature = "no_object"))]
         if TypeId::of::<T>() == TypeId::of::<Map>() {
             return match self.0 {
@@ -1757,6 +1794,13 @@ impl Dynamic {
                 _ => None,
             };
         }
+        #[cfg(not(feature = "no_index"))]
+        if TypeId::of::<T>() == TypeId::of::<Blob>() {
+            return match self.0 {
+                Union::Blob(ref mut value, _, _) => value.as_mut().as_mut_any().downcast_mut::<T>(),
+                _ => None,
+            };
+        }
         #[cfg(not(feature = "no_object"))]
         if TypeId::of::<T>() == TypeId::of::<Map>() {
             return match self.0 {
@@ -1798,7 +1842,7 @@ impl Dynamic {
             _ => None,
         }
     }
-    /// Cast the [`Dynamic`] as a unit `()` and return it.
+    /// Cast the [`Dynamic`] as a unit `()`.
     /// Returns the name of the actual type if the cast fails.
     #[inline]
     pub fn as_unit(&self) -> Result<(), &'static str> {
@@ -1809,7 +1853,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Cast the [`Dynamic`] as the system integer type [`INT`] and return it.
+    /// Cast the [`Dynamic`] as the system integer type [`INT`].
     /// Returns the name of the actual type if the cast fails.
     #[inline]
     pub fn as_int(&self) -> Result<INT, &'static str> {
@@ -1820,7 +1864,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Cast the [`Dynamic`] as the system floating-point type [`FLOAT`] and return it.
+    /// Cast the [`Dynamic`] as the system floating-point type [`FLOAT`].
     /// Returns the name of the actual type if the cast fails.
     ///
     /// Not available under `no_float`.
@@ -1834,7 +1878,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// _(decimal)_ Cast the [`Dynamic`] as a [`Decimal`](https://docs.rs/rust_decimal) and return it.
+    /// _(decimal)_ Cast the [`Dynamic`] as a [`Decimal`](https://docs.rs/rust_decimal).
     /// Returns the name of the actual type if the cast fails.
     ///
     /// Exported under the `decimal` feature only.
@@ -1848,7 +1892,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Cast the [`Dynamic`] as a [`bool`] and return it.
+    /// Cast the [`Dynamic`] as a [`bool`].
     /// Returns the name of the actual type if the cast fails.
     #[inline]
     pub fn as_bool(&self) -> Result<bool, &'static str> {
@@ -1859,7 +1903,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Cast the [`Dynamic`] as a [`char`] and return it.
+    /// Cast the [`Dynamic`] as a [`char`].
     /// Returns the name of the actual type if the cast fails.
     #[inline]
     pub fn as_char(&self) -> Result<char, &'static str> {
@@ -1870,7 +1914,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Cast the [`Dynamic`] as an [`ImmutableString`] and return it as a string slice.
+    /// Cast the [`Dynamic`] as a string slice.
     /// Returns the name of the actual type if the cast fails.
     ///
     /// # Panics
@@ -1885,7 +1929,7 @@ impl Dynamic {
             _ => Err(self.type_name()),
         }
     }
-    /// Convert the [`Dynamic`] into a [`String`] and return it.
+    /// Convert the [`Dynamic`] into a [`String`].
     /// If there are other references to the same string, a cloned copy is returned.
     /// Returns the name of the actual type if the cast fails.
     #[inline]
@@ -1893,7 +1937,7 @@ impl Dynamic {
         self.into_immutable_string()
             .map(ImmutableString::into_owned)
     }
-    /// Convert the [`Dynamic`] into an [`ImmutableString`] and return it.
+    /// Convert the [`Dynamic`] into an [`ImmutableString`].
     /// Returns the name of the actual type if the cast fails.
     #[inline]
     pub fn into_immutable_string(self) -> Result<ImmutableString, &'static str> {
@@ -2021,6 +2065,114 @@ impl<T: Variant + Clone> std::iter::FromIterator<T> for Dynamic {
         ))
     }
 }
+#[cfg(not(feature = "no_index"))]
+impl Dynamic {
+    /// Convert the [`Dynamic`] into an [`Array`].
+    /// Returns the name of the actual type if the cast fails.
+    #[inline(always)]
+    pub fn into_array(self) -> Result<Array, &'static str> {
+        match self.0 {
+            Union::Array(a, _, _) => Ok(*a),
+            #[cfg(not(feature = "no_closure"))]
+            Union::Shared(cell, _, _) => {
+                #[cfg(not(feature = "sync"))]
+                let value = cell.borrow();
+                #[cfg(feature = "sync")]
+                let value = cell.read().unwrap();
+
+                match value.0 {
+                    Union::Array(ref a, _, _) => Ok(a.as_ref().clone()),
+                    _ => Err((*value).type_name()),
+                }
+            }
+            _ => Err(self.type_name()),
+        }
+    }
+    /// Convert the [`Dynamic`] into a [`Vec`].
+    /// Returns the name of the actual type if any cast fails.
+    #[inline(always)]
+    pub fn into_typed_array<T: Variant + Clone>(self) -> Result<Vec<T>, &'static str> {
+        match self.0 {
+            Union::Array(a, _, _) => a
+                .into_iter()
+                .map(|v| {
+                    #[cfg(not(feature = "no_closure"))]
+                    let typ = if v.is_shared() {
+                        // Avoid panics/deadlocks with shared values
+                        "<shared>"
+                    } else {
+                        v.type_name()
+                    };
+                    #[cfg(feature = "no_closure")]
+                    let typ = v.type_name();
+
+                    v.try_cast::<T>().ok_or_else(|| typ)
+                })
+                .collect(),
+            Union::Blob(_, _, _) if TypeId::of::<T>() == TypeId::of::<u8>() => {
+                Ok(self.cast::<Vec<T>>())
+            }
+            #[cfg(not(feature = "no_closure"))]
+            Union::Shared(cell, _, _) => {
+                #[cfg(not(feature = "sync"))]
+                let value = cell.borrow();
+                #[cfg(feature = "sync")]
+                let value = cell.read().unwrap();
+
+                match value.0 {
+                    Union::Array(ref a, _, _) => {
+                        a.iter()
+                            .map(|v| {
+                                #[cfg(not(feature = "no_closure"))]
+                                let typ = if v.is_shared() {
+                                    // Avoid panics/deadlocks with shared values
+                                    "<shared>"
+                                } else {
+                                    v.type_name()
+                                };
+                                #[cfg(feature = "no_closure")]
+                                let typ = v.type_name();
+
+                                v.read_lock::<T>().ok_or_else(|| typ).map(|v| v.clone())
+                            })
+                            .collect()
+                    }
+                    _ => Err((*value).type_name()),
+                }
+            }
+            _ => Err(self.type_name()),
+        }
+    }
+}
+#[cfg(not(feature = "no_index"))]
+impl Dynamic {
+    /// Create a [`Dynamic`] from a [`Vec<u8>`].
+    #[inline(always)]
+    pub fn from_blob(blob: Blob) -> Self {
+        Self(Union::Blob(Box::new(blob), DEFAULT_TAG_VALUE, ReadWrite))
+    }
+    /// Convert the [`Dynamic`] into a [`Vec<u8>`].
+    /// Returns the name of the actual type if the cast fails.
+    #[inline(always)]
+    pub fn into_blob(self) -> Result<Blob, &'static str> {
+        match self.0 {
+            Union::Blob(a, _, _) => Ok(*a),
+            #[cfg(not(feature = "no_closure"))]
+            Union::Shared(cell, _, _) => {
+                #[cfg(not(feature = "sync"))]
+                let value = cell.borrow();
+                #[cfg(feature = "sync")]
+                let value = cell.read().unwrap();
+
+                match value.0 {
+                    Union::Blob(ref a, _, _) => Ok(a.as_ref().clone()),
+                    _ => Err((*value).type_name()),
+                }
+            }
+            _ => Err(self.type_name()),
+        }
+    }
+}
 #[cfg(not(feature = "no_object"))]
 impl Dynamic {
     /// Create a [`Dynamic`] from a [`Map`].

src/types/fn_ptr.rs

@@ -1,12 +1,15 @@
 //! The `FnPtr` type.
 
 use crate::tokenizer::is_valid_identifier;
+use crate::types::dynamic::Variant;
 use crate::{
-    Dynamic, EvalAltResult, Identifier, NativeCallContext, Position, RhaiResult, StaticVec,
+    Dynamic, Engine, EvalAltResult, FuncArgs, Identifier, Module, NativeCallContext, Position,
+    RhaiResult, StaticVec, AST,
 };
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 use std::{
+    any::type_name,
     convert::{TryFrom, TryInto},
     fmt, mem,
 };
@@ -96,22 +99,125 @@ impl FnPtr {
         self.0.starts_with(crate::engine::FN_ANONYMOUS)
     }
     /// Call the function pointer with curried arguments (if any).
+    /// The function may be script-defined (not available under `no_function`) or native Rust.
     ///
-    /// If this function is a script-defined function, it must not be marked private.
+    /// This method is intended for calling a function pointer directly, possibly on another [`Engine`].
+    /// Therefore, the [`AST`] is _NOT_ evaluated before calling the function.
     ///
-    /// # WARNING
+    /// # Example
+    ///
+    /// ```
+    /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
+    /// # #[cfg(not(feature = "no_function"))]
+    /// # {
+    /// use rhai::{Engine, FnPtr};
+    ///
+    /// let engine = Engine::new();
+    ///
+    /// let ast = engine.compile("fn foo(x, y) { len(x) + y }")?;
+    ///
+    /// let mut fn_ptr = FnPtr::new("foo")?;
+    ///
+    /// // Curry values into the function pointer
+    /// fn_ptr.set_curry(vec!["abc".into()]);
+    ///
+    /// // Values are only needed for non-curried parameters
+    /// let result: i64 = fn_ptr.call(&engine, &ast, ( 39_i64, ) )?;
+    ///
+    /// assert_eq!(result, 42);
+    /// # }
+    /// # Ok(())
+    /// # }
+    /// ```
+    #[inline]
+    pub fn call<T: Variant + Clone>(
+        &self,
+        engine: &Engine,
+        ast: &AST,
+        args: impl FuncArgs,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let _ast = ast;
+        let mut arg_values = crate::StaticVec::new_const();
+        args.parse(&mut arg_values);
+
+        let lib = [
+            #[cfg(not(feature = "no_function"))]
+            _ast.as_ref(),
+        ];
+        let lib = if lib.first().map(|m: &&Module| m.is_empty()).unwrap_or(true) {
+            &lib[0..0]
+        } else {
+            &lib
+        };
+        #[allow(deprecated)]
+        let ctx = NativeCallContext::new(engine, self.fn_name(), lib);
+
+        let result = self.call_raw(&ctx, None, arg_values)?;
+
+        let typ = engine.map_type_name(result.type_name());
+
+        result.try_cast().ok_or_else(|| {
+            EvalAltResult::ErrorMismatchOutputType(
+                engine.map_type_name(type_name::<T>()).into(),
+                typ.into(),
+                Position::NONE,
+            )
+            .into()
+        })
+    }
+    /// Call the function pointer with curried arguments (if any).
+    /// The function may be script-defined (not available under `no_function`) or native Rust.
+    ///
+    /// This method is intended for calling a function pointer that is passed into a native Rust
+    /// function as an argument.  Therefore, the [`AST`] is _NOT_ evaluated before calling the
+    /// function.
+    #[inline]
+    pub fn call_within_context<T: Variant + Clone>(
+        &self,
+        context: &NativeCallContext,
+        args: impl FuncArgs,
+    ) -> Result<T, Box<EvalAltResult>> {
+        let mut arg_values = crate::StaticVec::new_const();
+        args.parse(&mut arg_values);
+
+        let result = self.call_raw(&context, None, arg_values)?;
+
+        let typ = context.engine().map_type_name(result.type_name());
+
+        result.try_cast().ok_or_else(|| {
+            EvalAltResult::ErrorMismatchOutputType(
+                context.engine().map_type_name(type_name::<T>()).into(),
+                typ.into(),
+                Position::NONE,
+            )
+            .into()
+        })
+    }
+    /// Call the function pointer with curried arguments (if any).
+    /// The function may be script-defined (not available under `no_function`) or native Rust.
+    ///
+    /// This method is intended for calling a function pointer that is passed into a native Rust
+    /// function as an argument.  Therefore, the [`AST`] is _NOT_ evaluated before calling the
+    /// function.
+    ///
+    /// # WARNING - Low Level API
+    ///
+    /// This function is very low level.
+    ///
+    /// ## Arguments
     ///
     /// All the arguments are _consumed_, meaning that they're replaced by `()`.
     /// This is to avoid unnecessarily cloning the arguments.
     /// Do not use the arguments after this call. If they are needed afterwards,
     /// clone them _before_ calling this function.
     #[inline]
-    pub fn call_dynamic(
+    pub fn call_raw(
         &self,
-        ctx: &NativeCallContext,
+        context: &NativeCallContext,
         this_ptr: Option<&mut Dynamic>,
-        mut arg_values: impl AsMut<[Dynamic]>,
+        arg_values: impl AsMut<[Dynamic]>,
     ) -> RhaiResult {
+        let mut arg_values = arg_values;
         let mut arg_values = arg_values.as_mut();
         let mut args_data;
 
@@ -130,7 +236,7 @@ impl FnPtr {
         }
         args.extend(arg_values.iter_mut());
 
-        ctx.call_fn_raw(self.fn_name(), is_method, is_method, &mut args)
+        context.call_fn_raw(self.fn_name(), is_method, is_method, &mut args)
     }
 }
 
@@ -146,14 +252,13 @@ impl TryFrom<Identifier> for FnPtr {
     #[inline]
     fn try_from(value: Identifier) -> Result<Self, Self::Error> {
         if is_valid_identifier(value.chars()) {
-            Ok(Self(value, StaticVec::new()))
+            Ok(Self(value, StaticVec::new_const()))
         } else {
             Err(EvalAltResult::ErrorFunctionNotFound(value.to_string(), Position::NONE).into())
         }
     }
 }
 
-#[cfg(not(feature = "no_smartstring"))]
 impl TryFrom<crate::ImmutableString> for FnPtr {
     type Error = Box<EvalAltResult>;
 

src/types/immutable_string.rs

@@ -115,14 +115,12 @@ impl From<String> for ImmutableString {
         Self(value.into())
     }
 }
-#[cfg(not(feature = "no_smartstring"))]
 impl From<&SmartString> for ImmutableString {
     #[inline(always)]
     fn from(value: &SmartString) -> Self {
         Self(value.clone().into())
     }
 }
-#[cfg(not(feature = "no_smartstring"))]
 impl From<SmartString> for ImmutableString {
     #[inline(always)]
     fn from(value: SmartString) -> Self {
@@ -180,7 +178,6 @@ impl<'a> FromIterator<String> for ImmutableString {
     }
 }
 
-#[cfg(not(feature = "no_smartstring"))]
 impl<'a> FromIterator<SmartString> for ImmutableString {
     #[inline]
     fn from_iter<T: IntoIterator<Item = SmartString>>(iter: T) -> Self {
@@ -539,7 +536,7 @@ impl ImmutableString {
     /// Create a new [`ImmutableString`].
     #[inline(always)]
     pub fn new() -> Self {
-        Self(SmartString::new().into())
+        Self(SmartString::new_const().into())
     }
     /// Consume the [`ImmutableString`] and convert it into a [`String`].
     /// If there are other references to the same string, a cloned copy is returned.

src/types/parse_error.rs

@@ -11,10 +11,6 @@ use std::prelude::v1::*;
 
 /// _(internals)_ Error encountered when tokenizing the script text.
 /// Exported under the `internals` feature only.
-///
-/// # Volatile Data Structure
-///
-/// This type is volatile and may change.
 #[derive(Debug, Eq, PartialEq, Clone, Hash)]
 #[non_exhaustive]
 pub enum LexError {
@@ -168,6 +164,16 @@ pub enum ParseErrorType {
     /// Assignment to an inappropriate LHS (left-hand-side) expression.
     /// Wrapped value is the error message (if any).
     AssignmentToInvalidLHS(String),
+    /// A variable is not found.
+    ///
+    /// Only appears when strict variables mode is enabled.
+    VariableUndefined(String),
+    /// An imported module is not found.
+    ///
+    /// Only appears when strict variables mode is enabled.
+    ///
+    /// Never appears under the `no_module` feature.
+    ModuleUndefined(String),
     /// Expression exceeding the maximum levels of complexity.
     ///
     /// Never appears under the `unchecked` feature.
@@ -214,7 +220,7 @@ impl fmt::Display for ParseErrorType {
             },
 
             Self::FnDuplicatedDefinition(s, n) => {
-                write!(f, "Function '{}' with ", s)?;
+                write!(f, "Function {} with ", s)?;
                 match n {
                     0 => f.write_str("no parameters already exists"),
                     1 => f.write_str("1 parameter already exists"),
@@ -223,14 +229,17 @@ impl fmt::Display for ParseErrorType {
             }
             Self::FnMissingBody(s) => match s.as_str() {
                 "" => f.write_str("Expecting body statement block for anonymous function"),
-                s => write!(f, "Expecting body statement block for function '{}'", s)
+                s => write!(f, "Expecting body statement block for function {}", s)
             },
-            Self::FnMissingParams(s) => write!(f, "Expecting parameters for function '{}'", s),
+            Self::FnMissingParams(s) => write!(f, "Expecting parameters for function {}", s),
-            Self::FnDuplicatedParam(s, arg) => write!(f, "Duplicated parameter '{}' for function '{}'", arg, s),
+            Self::FnDuplicatedParam(s, arg) => write!(f, "Duplicated parameter {} for function {}", arg, s),
 
-            Self::DuplicatedProperty(s) => write!(f, "Duplicated property '{}' for object map literal", s),
+            Self::DuplicatedProperty(s) => write!(f, "Duplicated property for object map literal: {}", s),
             Self::DuplicatedSwitchCase => f.write_str("Duplicated switch case"),
-            Self::DuplicatedVariable(s) => write!(f, "Duplicated variable name '{}'", s),
+            Self::DuplicatedVariable(s) => write!(f, "Duplicated variable name: {}", s),
+
+            Self::VariableUndefined(s) => write!(f, "Undefined variable: {}", s),
+            Self::ModuleUndefined(s) => write!(f, "Undefined module: {}", s),
 
             Self::MismatchedType(r, a) => write!(f, "Expecting {}, not {}", r, a),
             Self::ExprExpected(s) => write!(f, "Expecting {} expression", s),
@@ -241,7 +250,7 @@ impl fmt::Display for ParseErrorType {
 
             Self::AssignmentToConstant(s) => match s.as_str() {
                 "" => f.write_str("Cannot assign to a constant value"),
-                s => write!(f, "Cannot assign to constant '{}'", s)
+                s => write!(f, "Cannot assign to constant {}", s)
             },
             Self::AssignmentToInvalidLHS(s) => match s.as_str() {
                 "" => f.write_str("Expression cannot be assigned to"),

src/types/scope.rs

@@ -2,6 +2,7 @@
 
 use super::dynamic::{AccessMode, Variant};
 use crate::{Dynamic, Identifier, StaticVec};
+use smallvec::SmallVec;
 use std::iter::FromIterator;
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
@@ -10,13 +11,13 @@ use std::{borrow::Cow, iter::Extend};
 /// Keep a number of entries inline (since [`Dynamic`] is usually small enough).
 const SCOPE_ENTRIES_INLINED: usize = 8;
 
-/// Type containing information about the current scope.
+/// Type containing information about the current scope. Useful for keeping state between
-/// Useful for keeping state between [`Engine`][crate::Engine] evaluation runs.
+/// [`Engine`][crate::Engine] evaluation runs.
 ///
 /// # Thread Safety
 ///
-/// Currently, [`Scope`] is neither [`Send`] nor [`Sync`].
+/// Currently, [`Scope`] is neither [`Send`] nor [`Sync`]. Turn on the `sync` feature to make it
-/// Turn on the `sync` feature to make it [`Send`] `+` [`Sync`].
+/// [`Send`] `+` [`Sync`].
 ///
 /// # Example
 ///
@@ -39,25 +40,25 @@ const SCOPE_ENTRIES_INLINED: usize = 8;
 /// # }
 /// ```
 ///
-/// When searching for entries, newly-added entries are found before similarly-named but older entries,
+/// When searching for entries, newly-added entries are found before similarly-named but older
-/// allowing for automatic _shadowing_.
+/// entries, allowing for automatic _shadowing_.
 //
 // # Implementation Notes
 //
-// [`Scope`] is implemented as two [`Vec`]'s of exactly the same length.  Variables data (name, type, etc.)
+// [`Scope`] is implemented as two [`Vec`]'s of exactly the same length.  Variables data (name,
-// is manually split into two equal-length arrays.  That's because variable names take up the most space,
+// type, etc.) is manually split into two equal-length arrays.  That's because variable names take
-// with [`Cow<str>`][Cow] being four words long, but in the vast majority of cases the name is NOT used to
+// up the most space, with [`Cow<str>`][Cow] being four words long, but in the vast majority of
-// look up a variable.  Variable lookup is usually via direct indexing, by-passing the name altogether.
+// cases the name is NOT used to look up a variable.  Variable lookup is usually via direct
+// indexing, by-passing the name altogether.
 //
-// Since [`Dynamic`] is reasonably small, packing it tightly improves cache locality when variables are accessed.
+// Since [`Dynamic`] is reasonably small, packing it tightly improves cache locality when variables
+// are accessed.
 #[derive(Debug, Clone, Hash, Default)]
 pub struct Scope<'a> {
     /// Current value of the entry.
-    values: smallvec::SmallVec<[Dynamic; SCOPE_ENTRIES_INLINED]>,
+    values: SmallVec<[Dynamic; SCOPE_ENTRIES_INLINED]>,
     /// (Name, aliases) of the entry.
-    names: smallvec::SmallVec<
+    names: SmallVec<[(Cow<'a, str>, Option<Box<StaticVec<Identifier>>>); SCOPE_ENTRIES_INLINED]>,
-        [(Cow<'a, str>, Option<Box<StaticVec<Identifier>>>); SCOPE_ENTRIES_INLINED],
-    >,
 }
 
 impl<'a> IntoIterator for Scope<'a> {
@@ -90,8 +91,11 @@ impl<'a> Scope<'a> {
     /// ```
     #[inline(always)]
     #[must_use]
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
-        Default::default()
+        Self {
+            values: SmallVec::new_const(),
+            names: SmallVec::new_const(),
+        }
     }
     /// Empty the [`Scope`].
     ///
@@ -297,22 +301,21 @@ impl<'a> Scope<'a> {
     #[inline]
     #[must_use]
     pub fn contains(&self, name: &str) -> bool {
-        self.names
+        self.names.iter().any(|(key, _)| name == key.as_ref())
-            .iter()
-            .rev() // Always search a Scope in reverse order
-            .any(|(key, _)| name == key.as_ref())
     }
     /// Find an entry in the [`Scope`], starting from the last.
     #[inline]
     #[must_use]
     pub(crate) fn get_index(&self, name: &str) -> Option<(usize, AccessMode)> {
+        let len = self.len();
+
         self.names
             .iter()
             .rev() // Always search a Scope in reverse order
             .enumerate()
-            .find_map(|(index, (key, _))| {
+            .find_map(|(i, (key, _))| {
                 if name == key.as_ref() {
-                    let index = self.len() - 1 - index;
+                    let index = len - 1 - i;
                     Some((index, self.values[index].access_mode()))
                 } else {
                     None
@@ -334,16 +337,14 @@ impl<'a> Scope<'a> {
     #[inline]
     #[must_use]
     pub fn get_value<T: Variant + Clone>(&self, name: &str) -> Option<T> {
+        let len = self.len();
+
         self.names
             .iter()
             .rev()
             .enumerate()
             .find(|(_, (key, _))| name == key.as_ref())
-            .and_then(|(index, _)| {
+            .and_then(|(index, _)| self.values[len - 1 - index].flatten_clone().try_cast())
-                self.values[self.len() - 1 - index]
-                    .flatten_clone()
-                    .try_cast()
-            })
     }
     /// Check if the named entry in the [`Scope`] is constant.
     ///
@@ -493,7 +494,7 @@ impl<'a> Scope<'a> {
     pub(crate) fn get_mut_by_index(&mut self, index: usize) -> &mut Dynamic {
         self.values.get_mut(index).expect("valid index")
     }
-    /// Update the access type of an entry in the [`Scope`].
+    /// Add an alias to an entry in the [`Scope`].
     ///
     /// # Panics
     ///
@@ -504,7 +505,7 @@ impl<'a> Scope<'a> {
         let (_, aliases) = self.names.get_mut(index).expect("valid index");
         match aliases {
             None => {
-                let mut list = StaticVec::new();
+                let mut list = StaticVec::new_const();
                 list.push(alias);
                 *aliases = Some(list.into());
             }
@@ -518,14 +519,14 @@ impl<'a> Scope<'a> {
     #[inline]
     #[must_use]
     pub fn clone_visible(&self) -> Self {
+        let len = self.len();
+
         self.names.iter().rev().enumerate().fold(
             Self::new(),
             |mut entries, (index, (name, alias))| {
                 if !entries.names.iter().any(|(key, _)| key == name) {
                     entries.names.push((name.clone(), alias.clone()));
-                    entries
+                    entries.values.push(self.values[len - 1 - index].clone());
-                        .values
-                        .push(self.values[self.len() - 1 - index].clone());
                 }
                 entries
             },

tests/arrays.rs

@@ -1,9 +1,5 @@
 #![cfg(not(feature = "no_index"))]
-use rhai::{Array, Engine, EvalAltResult, INT};
+use rhai::{Array, Dynamic, Engine, EvalAltResult, INT};
-
-fn convert_to_vec<T: Clone + 'static>(array: Array) -> Vec<T> {
-    array.into_iter().map(|v| v.clone_cast::<T>()).collect()
-}
 
 #[test]
 fn test_arrays() -> Result<(), Box<EvalAltResult>> {
@@ -27,30 +23,42 @@ fn test_arrays() -> Result<(), Box<EvalAltResult>> {
     assert!(engine.eval::<bool>("let y = [1, 2, 3]; 2 in y")?);
     assert_eq!(engine.eval::<INT>("let y = [1, 2, 3]; y += 4; y[3]")?, 4);
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y[1] += 4; y")?),
+        engine
+            .eval::<Dynamic>("let y = [1, 2, 3]; y[1] += 4; y")?
+            .into_typed_array::<INT>()?,
         [1, 6, 3]
     );
 
     #[cfg(not(feature = "no_object"))]
     {
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y.push(4); y")?),
+            engine
+                .eval::<Dynamic>("let y = [1, 2, 3]; y.push(4); y")?
+                .into_typed_array::<INT>()?,
             [1, 2, 3, 4]
         );
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y.insert(0, 4); y")?),
+            engine
+                .eval::<Dynamic>("let y = [1, 2, 3]; y.insert(0, 4); y")?
+                .into_typed_array::<INT>()?,
             [4, 1, 2, 3]
         );
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y.insert(999, 4); y")?),
+            engine
+                .eval::<Dynamic>("let y = [1, 2, 3]; y.insert(999, 4); y")?
+                .into_typed_array::<INT>()?,
             [1, 2, 3, 4]
         );
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y.insert(-2, 4); y")?),
+            engine
+                .eval::<Dynamic>("let y = [1, 2, 3]; y.insert(-2, 4); y")?
+                .into_typed_array::<INT>()?,
             [1, 4, 2, 3]
         );
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval("let y = [1, 2, 3]; y.insert(-999, 4); y")?),
+            engine
+                .eval::<Dynamic>("let y = [1, 2, 3]; y.insert(-999, 4); y")?
+                .into_typed_array::<INT>()?,
             [4, 1, 2, 3]
         );
         assert_eq!(
@@ -67,43 +75,49 @@ fn test_arrays() -> Result<(), Box<EvalAltResult>> {
         );
 
         assert_eq!(
-            convert_to_vec::<INT>(engine.eval(
+            engine
-                "
+                .eval::<Dynamic>(
-                    let x = [2, 9];
+                    "
-                    x.insert(-1, 1);
+                        let x = [2, 9];
-                    x.insert(999, 3);
+                        x.insert(-1, 1);
-                    x.insert(-9, 99);
+                        x.insert(999, 3);
+                        x.insert(-9, 99);
 
-                    let r = x.remove(2);
+                        let r = x.remove(2);
 
-                    let y = [4, 5];
+                        let y = [4, 5];
-                    x.append(y);
+                        x.append(y);
 
-                    x 
+                        x 
-                "
+                    "
-            )?),
+                )?
+                .into_typed_array::<INT>()?,
             [99, 2, 9, 3, 4, 5]
         );
     }
 
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                x += [4, 5];
+                    let x = [1, 2, 3];
-                x
+                    x += [4, 5];
-            "
+                    x
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [1, 2, 3, 4, 5]
     );
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                let y = [4, 5];
+                    let x = [1, 2, 3];
-                x + y
+                    let y = [4, 5];
-            "
+                    x + y
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [1, 2, 3, 4, 5]
     );
 
@@ -170,44 +184,56 @@ fn test_arrays_map_reduce() -> Result<(), Box<EvalAltResult>> {
 
     assert_eq!(engine.eval::<INT>("[1].map(|x| x + 41)[0]")?, 42);
     assert_eq!(engine.eval::<INT>("([1].map(|x| x + 41))[0]")?, 42);
+    assert_eq!(
+        engine.eval::<INT>("let c = 40; let y = 1; [1].map(|x, i| c + x + y + i)[0]")?,
+        42
+    );
 
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                x.filter(|v| v > 2)
+                    let x = [1, 2, 3];
-            "
+                    x.filter(|v| v > 2)
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [3]
     );
 
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                x.filter(|v, i| v > i)
+                    let x = [1, 2, 3];
-            "
+                    x.filter(|v, i| v > i)
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [1, 2, 3]
     );
 
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                x.map(|v| v * 2)
+                    let x = [1, 2, 3];
-            "
+                    x.map(|v| v * 2)
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [2, 4, 6]
     );
 
     assert_eq!(
-        convert_to_vec::<INT>(engine.eval(
+        engine
-            "
+            .eval::<Dynamic>(
-                let x = [1, 2, 3];
+                "
-                x.map(|v, i| v * i)
+                    let x = [1, 2, 3];
-            "
+                    x.map(|v, i| v * i)
-        )?),
+                "
+            )?
+            .into_typed_array::<INT>()?,
         [0, 2, 6]
     );
 

tests/blobs.rs

@@ -0,0 +1,68 @@
+#![cfg(not(feature = "no_index"))]
+use rhai::{Blob, Engine, EvalAltResult, Scope, INT};
+
+#[test]
+fn test_blobs() -> Result<(), Box<EvalAltResult>> {
+    let mut a = Blob::new();
+    a.push(1);
+    a.push(2);
+    a.push(3);
+
+    let engine = Engine::new();
+    let mut orig_scope = Scope::new();
+    orig_scope.push("x", a);
+
+    let mut scope = orig_scope.clone();
+
+    assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x[1]")?, 2);
+    assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x[0]")?, 1);
+    assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x[-1]")?, 3);
+    assert_eq!(engine.eval_with_scope::<INT>(&mut scope, "x[-3]")?, 1);
+    assert_eq!(
+        engine.eval_with_scope::<INT>(&mut scope, "x += 4; x[3]")?,
+        4
+    );
+
+    #[cfg(not(feature = "no_object"))]
+    {
+        assert_eq!(
+            engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x.push(4); x")?,
+            [1, 2, 3, 4]
+        );
+        assert_eq!(
+            engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x.insert(0, 4); x")?,
+            [4, 1, 2, 3]
+        );
+        assert_eq!(
+            engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x.insert(999, 4); x")?,
+            [1, 2, 3, 4]
+        );
+        assert_eq!(
+            engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x.insert(-2, 4); x")?,
+            [1, 4, 2, 3]
+        );
+        assert_eq!(
+            engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x.insert(-999, 4); x")?,
+            [4, 1, 2, 3]
+        );
+        assert_eq!(
+            engine.eval_with_scope::<INT>(&mut orig_scope.clone(), "let z = [42]; x[z.len]")?,
+            2
+        );
+        assert_eq!(
+            engine.eval_with_scope::<INT>(&mut orig_scope.clone(), "let z = [2]; x[z[0]]")?,
+            3
+        );
+    }
+
+    assert_eq!(
+        engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x += x; x")?,
+        [1, 2, 3, 1, 2, 3]
+    );
+    assert_eq!(
+        engine.eval_with_scope::<Blob>(&mut orig_scope.clone(), "x + x")?,
+        [1, 2, 3, 1, 2, 3]
+    );
+
+    Ok(())
+}

tests/call_fn.rs

@@ -132,7 +132,6 @@ fn test_call_fn_private() -> Result<(), Box<EvalAltResult>> {
 fn test_fn_ptr_raw() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
 
-    #[allow(deprecated)]
     engine
         .register_fn("mul", |x: &mut INT, y: INT| *x *= y)
         .register_raw_fn(
@@ -147,7 +146,7 @@ fn test_fn_ptr_raw() -> Result<(), Box<EvalAltResult>> {
                 let value = args[2].clone();
                 let this_ptr = args.get_mut(0).unwrap();
 
-                fp.call_dynamic(&context, Some(this_ptr), [value])
+                fp.call_raw(&context, Some(this_ptr), [value])
             },
         );
 

tests/closures.rs

@@ -1,5 +1,5 @@
 #![cfg(not(feature = "no_function"))]
-use rhai::{Engine, EvalAltResult, FnPtr, NativeCallContext, ParseErrorType, Scope, INT};
+use rhai::{Engine, EvalAltResult, FnPtr, ParseErrorType, Scope, INT};
 use std::any::TypeId;
 use std::cell::RefCell;
 use std::mem::take;
@@ -12,13 +12,12 @@ use rhai::Map;
 fn test_fn_ptr_curry_call() -> Result<(), Box<EvalAltResult>> {
     let mut engine = Engine::new();
 
-    #[allow(deprecated)]
     engine.register_raw_fn(
         "call_with_arg",
         &[TypeId::of::<FnPtr>(), TypeId::of::<INT>()],
         |context, args| {
             let fn_ptr = std::mem::take(args[0]).cast::<FnPtr>();
-            fn_ptr.call_dynamic(&context, None, [std::mem::take(args[1])])
+            fn_ptr.call_raw(&context, None, [std::mem::take(args[1])])
         },
     );
 
@@ -150,14 +149,13 @@ fn test_closures() -> Result<(), Box<EvalAltResult>> {
         42
     );
 
-    #[allow(deprecated)]
     engine.register_raw_fn(
         "custom_call",
         &[TypeId::of::<INT>(), TypeId::of::<FnPtr>()],
         |context, args| {
             let func = take(args[1]).cast::<FnPtr>();
 
-            func.call_dynamic(&context, None, [])
+            func.call_raw(&context, None, [])
         },
     );
 
@@ -320,30 +318,18 @@ fn test_closures_shared_obj() -> Result<(), Box<EvalAltResult>> {
 fn test_closures_external() -> Result<(), Box<EvalAltResult>> {
     let engine = Engine::new();
 
-    let mut ast = engine.compile(
+    let ast = engine.compile(
         r#"
             let test = "hello";
             |x| test + x
         "#,
     )?;
 
-    // Save the function pointer together with captured variables
     let fn_ptr = engine.eval_ast::<FnPtr>(&ast)?;
 
-    // Get rid of the script, retaining only functions
+    let f = move |x: INT| -> String { fn_ptr.call(&engine, &ast, (x,)).unwrap() };
-    ast.retain_functions(|_, _, _, _| true);
 
-    // Create function namespace from the 'AST'
+    assert_eq!(f(42), "hello42");
-    let lib = [ast.as_ref()];
-
-    // Create native call context
-    let fn_name = fn_ptr.fn_name().to_string();
-    let context = NativeCallContext::new(&engine, &fn_name, &lib);
-
-    // Closure  'f' captures: the engine, the AST, and the curried function pointer
-    let f = move |x: INT| fn_ptr.call_dynamic(&context, None, [x.into()]);
-
-    assert_eq!(f(42)?.into_string(), Ok("hello42".to_string()));
 
     Ok(())
 }

tests/fn_ptr.rs

@@ -1,4 +1,4 @@
-use rhai::{Engine, EvalAltResult, INT};
+use rhai::{Engine, EvalAltResult, FnPtr, INT};
 
 #[test]
 fn test_fn_ptr() -> Result<(), Box<EvalAltResult>> {
@@ -111,3 +111,43 @@ fn test_fn_ptr_curry() -> Result<(), Box<EvalAltResult>> {
 
     Ok(())
 }
+
+#[test]
+#[cfg(not(feature = "no_function"))]
+fn test_fn_ptr_call() -> Result<(), Box<EvalAltResult>> {
+    let engine = Engine::new();
+
+    let ast = engine.compile("private fn foo(x, y) { len(x) + y }")?;
+
+    let mut fn_ptr = FnPtr::new("foo")?;
+    fn_ptr.set_curry(vec!["abc".into()]);
+    let result: INT = fn_ptr.call(&engine, &ast, (39 as INT,))?;
+
+    assert_eq!(result, 42);
+
+    Ok(())
+}
+
+#[test]
+#[cfg(not(feature = "no_closure"))]
+fn test_fn_ptr_make_closure() -> Result<(), Box<EvalAltResult>> {
+    let f = {
+        let engine = Engine::new();
+
+        let ast = engine.compile(
+            r#"
+                let test = "hello";
+                |x| test + x            // this creates a closure
+            "#,
+        )?;
+
+        let fn_ptr = engine.eval_ast::<FnPtr>(&ast)?;
+
+        move |x: INT| -> Result<String, _> { fn_ptr.call(&engine, &ast, (x,)) }
+    };
+
+    // 'f' captures: the Engine, the AST, and the closure
+    assert_eq!(f(42)?, "hello42");
+
+    Ok(())
+}

tests/functions.rs

@@ -98,8 +98,8 @@ fn test_functions_global_module() -> Result<(), Box<EvalAltResult>> {
 
     engine.register_result_fn(
         "do_stuff",
-        |context: NativeCallContext, callback: rhai::FnPtr| {
+        |context: NativeCallContext, callback: rhai::FnPtr| -> Result<INT, _> {
-            callback.call_dynamic(&context, None, [])
+            callback.call_within_context(&context, ())
         },
     );
 

tests/native.rs

@@ -30,7 +30,6 @@ fn test_native_context_fn_name() -> Result<(), Box<EvalAltResult>> {
 
     let mut engine = Engine::new();
 
-    #[allow(deprecated)]
     engine
         .register_raw_fn(
             "add_double",

tests/optimizer.rs

@@ -69,6 +69,7 @@ fn test_optimizer_run() -> Result<(), Box<EvalAltResult>> {
 }
 
 #[cfg(not(feature = "no_module"))]
+#[cfg(not(feature = "no_function"))]
 #[cfg(not(feature = "no_position"))]
 #[test]
 fn test_optimizer_parse() -> Result<(), Box<EvalAltResult>> {

tests/options.rs

@@ -0,0 +1,91 @@
+use rhai::{Engine, EvalAltResult};
+
+#[test]
+fn test_options_allow() -> Result<(), Box<EvalAltResult>> {
+    let mut engine = Engine::new();
+
+    engine.compile("let x = if y { z } else { w };")?;
+
+    engine.set_allow_if_expression(false);
+
+    assert!(engine.compile("let x = if y { z } else { w };").is_err());
+
+    engine.compile("let x = { let z = 0; z + 1 };")?;
+
+    engine.set_allow_statement_expression(false);
+
+    assert!(engine.compile("let x = { let z = 0; z + 1 };").is_err());
+
+    #[cfg(not(feature = "no_function"))]
+    {
+        engine.compile("let x = || 42;")?;
+
+        engine.set_allow_anonymous_fn(false);
+
+        assert!(engine.compile("let x = || 42;").is_err());
+    }
+
+    engine.compile("while x > y { foo(z); }")?;
+
+    engine.set_allow_looping(false);
+
+    assert!(engine.compile("while x > y { foo(z); }").is_err());
+
+    Ok(())
+}
+
+#[test]
+fn test_options_strict_var() -> Result<(), Box<EvalAltResult>> {
+    let mut engine = Engine::new();
+
+    engine.compile("let x = if y { z } else { w };")?;
+
+    #[cfg(not(feature = "no_function"))]
+    engine.compile("fn foo(x) { x + y }")?;
+
+    #[cfg(not(feature = "no_module"))]
+    engine.compile("print(h::y::z);")?;
+
+    #[cfg(not(feature = "no_module"))]
+    engine.compile("let x = h::y::foo();")?;
+
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(not(feature = "no_module"))]
+    engine.compile("fn foo() { h::y::foo() }")?;
+
+    #[cfg(not(feature = "no_function"))]
+    engine.compile("let f = |y| x * y;")?;
+
+    engine.set_strict_variables(true);
+
+    assert!(engine.compile("let x = if y { z } else { w };").is_err());
+    engine.compile("let y = 42; let x = y;")?;
+
+    #[cfg(not(feature = "no_function"))]
+    assert!(engine.compile("fn foo(x) { x + y }").is_err());
+
+    #[cfg(not(feature = "no_module"))]
+    {
+        assert!(engine.compile("print(h::y::z);").is_err());
+        engine.compile(r#"import "hello" as h; print(h::y::z);"#)?;
+        assert!(engine.compile("let x = h::y::foo();").is_err());
+        engine.compile(r#"import "hello" as h; let x = h::y::foo();"#)?;
+    }
+
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(not(feature = "no_module"))]
+    engine.compile("fn foo() { h::y::foo() }")?;
+
+    #[cfg(not(feature = "no_function"))]
+    {
+        assert!(engine.compile("let f = |y| x * y;").is_err());
+        #[cfg(not(feature = "no_closure"))]
+        {
+            engine.compile("let x = 42; let f = |y| x * y;")?;
+            engine.compile("let x = 42; let f = |y| { || x + y };")?;
+            assert!(engine.compile("fn foo() { |y| { || x + y } }").is_err());
+        }
+    }
+
+    Ok(())
+}

tests/serde.rs

@@ -746,3 +746,52 @@ fn test_serde_json() -> serde_json::Result<()> {
 
     Ok(())
 }
+
+#[test]
+#[cfg(not(feature = "no_object"))]
+fn test_serde_optional() -> Result<(), Box<EvalAltResult>> {
+    #[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+    struct TestStruct {
+        foo: Option<char>,
+    }
+
+    let mut engine = Engine::new();
+    engine.register_type_with_name::<TestStruct>("TestStruct");
+
+    let r = engine.eval::<Dynamic>("#{ foo: 'a' }")?;
+
+    assert_eq!(
+        from_dynamic::<TestStruct>(&r)?,
+        TestStruct { foo: Some('a') }
+    );
+
+    let r = engine.eval::<Dynamic>("#{ foo: () }")?;
+
+    assert_eq!(from_dynamic::<TestStruct>(&r)?, TestStruct { foo: None });
+
+    let r = engine.eval::<Dynamic>("#{ }")?;
+
+    assert_eq!(from_dynamic::<TestStruct>(&r)?, TestStruct { foo: None });
+
+    Ok(())
+}
+
+#[test]
+#[cfg(not(feature = "no_index"))]
+fn test_serde_blob() -> Result<(), Box<EvalAltResult>> {
+    let engine = Engine::new();
+
+    let r = engine.eval::<Dynamic>(
+        "
+            let x = blob(10);
+            for i in range(0, 10) { x[i] = i; }
+            x
+        ",
+    )?;
+
+    let r = from_dynamic::<serde_bytes::ByteBuf>(&r)?;
+
+    assert_eq!(r.to_vec(), vec![0_u8, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
+
+    Ok(())
+}