Refine no_function feature.

Cargo.toml

@@ -21,7 +21,7 @@ num-traits = { version = "0.2.11", default-features = false }
 
 [features]
 #default = ["unchecked", "sync", "no_optimize", "no_float", "only_i32", "no_index", "no_object", "no_function", "no_module"]
-default = ["serde"]
+default = []
 plugins = []
 unchecked = []      # unchecked arithmetic
 sync = []           # restrict to only types that implement Send + Sync

README.md

@@ -29,7 +29,7 @@ Features
 * Fairly efficient evaluation (1 million iterations in 0.4 sec on a single core, 2.3 GHz Linux VM).
 * Relatively little `unsafe` code (yes there are some for performance reasons, and most `unsafe` code is limited to
   one single source file, all with names starting with `"unsafe_"`).
-* Re-entrant scripting engine can be made `Send + Sync` (via the [`sync`] feature).
+* Re-entrant scripting engine can be made `Send + Sync` (via the `sync` feature).
 * Sand-boxed - the scripting engine, if declared immutable, cannot mutate the containing environment unless explicitly permitted (e.g. via a `RefCell`).
 * Rugged - protected against malicious attacks (such as [stack-overflow](https://schungx.github.io/rhai/safety/max-call-stack.html), [over-sized data](https://schungx.github.io/rhai/safety/max-string-size.html), and [runaway scripts](https://schungx.github.io/rhai/safety/max-operations.html) etc.) that may come from untrusted third-party user-land scripts.
 * Track script evaluation [progress](https://schungx.github.io/rhai/safety/progress.html) and manually terminate a script run.
@@ -38,7 +38,7 @@ Features
 * Dynamic dispatch via [function pointers](https://schungx.github.io/rhai/language/fn-ptr.html).
 * Some support for [object-oriented programming (OOP)](https://schungx.github.io/rhai/language/oop.html).
 * Organize code base with dynamically-loadable [modules](https://schungx.github.io/rhai/language/modules.html).
-* Serialization/deserialization support via [serde](https://crates.io/crates/serde)
+* Serialization/deserialization support via [serde](https://crates.io/crates/serde) (requires the `serde` feature).
 * Scripts are [optimized](https://schungx.github.io/rhai/engine/optimize.html) (useful for template-based machine-generated scripts) for repeated evaluations.
 * Support for [minimal builds](https://schungx.github.io/rhai/start/builds/minimal.html) by excluding unneeded language [features](https://schungx.github.io/rhai/start/features.html).
 

src/api.rs

@@ -1,10 +1,7 @@
 //! Module that defines the extern API of `Engine`.
 
 use crate::any::{Dynamic, Variant};
-use crate::engine::{
+use crate::engine::{make_getter, make_setter, Engine, Imports, State, FN_IDX_GET, FN_IDX_SET};
-    get_script_function_by_signature, make_getter, make_setter, Engine, Imports, State, FN_IDX_GET,
-    FN_IDX_SET,
-};
 use crate::error::ParseError;
 use crate::fn_call::FuncArgs;
 use crate::fn_native::{IteratorFn, SendSync};
@@ -19,6 +16,9 @@ use crate::utils::StaticVec;
 #[cfg(not(feature = "no_object"))]
 use crate::engine::Map;
 
+#[cfg(not(feature = "no_function"))]
+use crate::engine::get_script_function_by_signature;
+
 use crate::stdlib::{
     any::{type_name, TypeId},
     boxed::Box,
@@ -1189,6 +1189,7 @@ impl Engine {
     /// 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.
+    #[cfg(not(feature = "no_function"))]
     pub(crate) fn call_fn_dynamic_raw(
         &self,
         scope: &mut Scope,
@@ -1240,6 +1241,7 @@ impl Engine {
         mut ast: AST,
         optimization_level: OptimizationLevel,
     ) -> AST {
+        #[cfg(not(feature = "no_function"))]
         let lib = ast
             .lib()
             .iter_fn()
@@ -1247,6 +1249,9 @@ impl Engine {
             .map(|(_, _, _, f)| f.get_fn_def().clone())
             .collect();
 
+        #[cfg(feature = "no_function")]
+        let lib = Default::default();
+
         let stmt = mem::take(ast.statements_mut());
         optimize_into_ast(self, scope, stmt, lib, optimization_level)
     }

src/engine.rs

@@ -216,6 +216,7 @@ impl State {
 }
 
 /// Get a script-defined function definition from a module.
+#[cfg(not(feature = "no_function"))]
 pub fn get_script_function_by_signature<'a>(
     module: &'a Module,
     name: &str,
@@ -767,22 +768,23 @@ impl Engine {
         .or_else(|| self.packages.get_fn(hash_fn));
 
         if let Some(func) = func {
-            // Calling pure function but the first argument is a reference?
+            #[cfg(not(feature = "no_function"))]
-            normalize_first_arg(
+            let need_normalize = is_ref && (func.is_pure() || (func.is_script() && !is_method));
-                is_ref && (func.is_pure() || (func.is_script() && !is_method)),
+            #[cfg(feature = "no_function")]
-                &mut this_copy,
+            let need_normalize = is_ref && func.is_pure();
-                &mut old_this_ptr,
-                args,
-            );
 
+            // Calling pure function but the first argument is a reference?
+            normalize_first_arg(need_normalize, &mut this_copy, &mut old_this_ptr, args);
+
+            #[cfg(not(feature = "no_function"))]
             if func.is_script() {
                 // Run scripted function
                 let fn_def = func.get_fn_def();
 
                 // Method call of script function - map first argument to `this`
-                if is_method {
+                return if is_method {
                     let (first, rest) = args.split_at_mut(1);
-                    return Ok((
+                    Ok((
                         self.call_script_fn(
                             scope,
                             mods,
@@ -795,7 +797,7 @@ impl Engine {
                             level,
                         )?,
                         false,
-                    ));
+                    ))
                 } else {
                     let result = self.call_script_fn(
                         scope, mods, state, lib, &mut None, fn_name, fn_def, args, level,
@@ -804,9 +806,10 @@ impl Engine {
                     // Restore the original reference
                     restore_first_arg(old_this_ptr, args);
 
-                    return Ok((result, false));
+                    Ok((result, false))
                 };
-            } else {
+            }
+
             // Run external function
             let result = func.get_native_fn()(self, args)?;
 
@@ -840,7 +843,6 @@ impl Engine {
                 _ => (result, func.is_method()),
             });
         }
-        }
 
         // See if it is built in.
         if args.len() == 2 {
@@ -2016,6 +2018,7 @@ impl Engine {
                 };
 
                 match func {
+                    #[cfg(not(feature = "no_function"))]
                     Ok(f) if f.is_script() => {
                         let args = args.as_mut();
                         let fn_def = f.get_fn_def();

src/fn_native.rs

@@ -114,6 +114,7 @@ pub enum CallableFunction {
     /// An iterator function.
     Iterator(IteratorFn),
     /// A script-defined function.
+    #[cfg(not(feature = "no_function"))]
     Script(Shared<ScriptFnDef>),
 }
 
@@ -123,6 +124,8 @@ impl fmt::Debug for CallableFunction {
             Self::Pure(_) => write!(f, "NativePureFunction"),
             Self::Method(_) => write!(f, "NativeMethod"),
             Self::Iterator(_) => write!(f, "NativeIterator"),
+
+            #[cfg(not(feature = "no_function"))]
             Self::Script(fn_def) => fmt::Debug::fmt(fn_def, f),
         }
     }
@@ -134,6 +137,8 @@ impl fmt::Display for CallableFunction {
             Self::Pure(_) => write!(f, "NativePureFunction"),
             Self::Method(_) => write!(f, "NativeMethod"),
             Self::Iterator(_) => write!(f, "NativeIterator"),
+
+            #[cfg(not(feature = "no_function"))]
             CallableFunction::Script(s) => fmt::Display::fmt(s, f),
         }
     }
@@ -144,24 +149,34 @@ impl CallableFunction {
     pub fn is_pure(&self) -> bool {
         match self {
             Self::Pure(_) => true,
-            Self::Method(_) | Self::Iterator(_) | Self::Script(_) => false,
+            Self::Method(_) | Self::Iterator(_) => false,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
         }
     }
     /// Is this a native Rust method function?
     pub fn is_method(&self) -> bool {
         match self {
             Self::Method(_) => true,
-            Self::Pure(_) | Self::Iterator(_) | Self::Script(_) => false,
+            Self::Pure(_) | Self::Iterator(_) => false,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
         }
     }
     /// Is this an iterator function?
     pub fn is_iter(&self) -> bool {
         match self {
             Self::Iterator(_) => true,
-            Self::Pure(_) | Self::Method(_) | Self::Script(_) => false,
+            Self::Pure(_) | Self::Method(_) => false,
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => false,
         }
     }
     /// Is this a Rhai-scripted function?
+    #[cfg(not(feature = "no_function"))]
     pub fn is_script(&self) -> bool {
         match self {
             Self::Script(_) => true,
@@ -176,7 +191,10 @@ impl CallableFunction {
     pub fn get_native_fn(&self) -> &FnAny {
         match self {
             Self::Pure(f) | Self::Method(f) => f.as_ref(),
-            Self::Iterator(_) | Self::Script(_) => unreachable!(),
+            Self::Iterator(_) => unreachable!(),
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => unreachable!(),
         }
     }
     /// Get a shared reference to a script-defined function definition.
@@ -184,6 +202,7 @@ impl CallableFunction {
     /// # Panics
     ///
     /// Panics if the `CallableFunction` is not `Script`.
+    #[cfg(not(feature = "no_function"))]
     pub fn get_shared_fn_def(&self) -> Shared<ScriptFnDef> {
         match self {
             Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => unreachable!(),
@@ -195,6 +214,7 @@ impl CallableFunction {
     /// # Panics
     ///
     /// Panics if the `CallableFunction` is not `Script`.
+    #[cfg(not(feature = "no_function"))]
     pub fn get_fn_def(&self) -> &ScriptFnDef {
         match self {
             Self::Pure(_) | Self::Method(_) | Self::Iterator(_) => unreachable!(),
@@ -209,7 +229,10 @@ impl CallableFunction {
     pub fn get_iter_fn(&self) -> IteratorFn {
         match self {
             Self::Iterator(f) => *f,
-            Self::Pure(_) | Self::Method(_) | Self::Script(_) => unreachable!(),
+            Self::Pure(_) | Self::Method(_) => unreachable!(),
+
+            #[cfg(not(feature = "no_function"))]
+            Self::Script(_) => unreachable!(),
         }
     }
     /// Create a new `CallableFunction::Pure`.
@@ -228,12 +251,14 @@ impl From<IteratorFn> for CallableFunction {
     }
 }
 
+#[cfg(not(feature = "no_function"))]
 impl From<ScriptFnDef> for CallableFunction {
     fn from(func: ScriptFnDef) -> Self {
         Self::Script(func.into())
     }
 }
 
+#[cfg(not(feature = "no_function"))]
 impl From<Shared<ScriptFnDef>> for CallableFunction {
     fn from(func: Shared<ScriptFnDef>) -> Self {
         Self::Script(func)

src/lib.rs

@@ -125,17 +125,23 @@ pub use parser::FLOAT;
 pub use module::ModuleResolver;
 
 /// Module containing all built-in _module resolvers_ available to Rhai.
+///
+/// Not available under the `no_module` feature.
 #[cfg(not(feature = "no_module"))]
 pub mod module_resolvers {
     pub use crate::module::resolvers::*;
 }
 
 /// Serialization support for [`serde`](https://crates.io/crates/serde).
+///
+/// Requires the `serde` feature.
 #[cfg(feature = "serde")]
 pub mod ser {
     pub use crate::serde::ser::to_dynamic;
 }
 /// Deserialization support for [`serde`](https://crates.io/crates/serde).
+///
+/// Requires the `serde` feature.
 #[cfg(feature = "serde")]
 pub mod de {
     pub use crate::serde::de::from_dynamic;

src/module.rs

@@ -236,6 +236,7 @@ impl Module {
     /// Set a script-defined function into the module.
     ///
     /// If there is an existing function of the same name and number of arguments, it is replaced.
+    #[cfg(not(feature = "no_function"))]
     pub(crate) fn set_script_fn(&mut self, fn_def: ScriptFnDef) {
         // None + function name + number of arguments.
         let hash_script = calc_fn_hash(empty(), &fn_def.name, fn_def.params.len(), empty());
@@ -876,6 +877,7 @@ impl Module {
                 .functions
                 .iter()
                 .filter(|(_, (_, _, _, v))| match v {
+                    #[cfg(not(feature = "no_function"))]
                     CallableFunction::Script(ref f) => {
                         filter(f.access, f.name.as_str(), f.params.len())
                     }
@@ -893,6 +895,7 @@ impl Module {
     }
 
     /// Filter out the functions, retaining only some based on a filter predicate.
+    #[cfg(not(feature = "no_function"))]
     pub(crate) fn retain_functions(&mut self, filter: impl Fn(FnAccess, &str, usize) -> bool) {
         self.functions.retain(|_, (_, _, _, v)| match v {
             CallableFunction::Script(ref f) => filter(f.access, f.name.as_str(), f.params.len()),
@@ -930,6 +933,7 @@ impl Module {
     }
 
     /// Get an iterator over all script-defined functions in the module.
+    #[cfg(not(feature = "no_function"))]
     pub fn iter_script_fn<'a>(&'a self) -> impl Iterator<Item = Shared<ScriptFnDef>> + 'a {
         self.functions
             .values()
@@ -1014,6 +1018,7 @@ impl Module {
                     Public => (),
                 }
 
+                #[cfg(not(feature = "no_function"))]
                 if func.is_script() {
                     let fn_def = func.get_shared_fn_def();
                     // Qualifiers + function name + number of arguments.
@@ -1024,7 +1029,9 @@ impl Module {
                         empty(),
                     );
                     functions.push((hash_qualified_script, fn_def.into()));
-                } else {
+                    continue;
+                }
+
                 // Qualified Rust functions are indexed in two steps:
                 // 1) Calculate a hash in a similar manner to script-defined functions,
                 //    i.e. qualifiers + function name + number of arguments.
@@ -1039,7 +1046,6 @@ impl Module {
                 functions.push((hash_qualified_fn, func.clone()));
             }
         }
-        }
 
         if self.indexed {
             return;

src/optimize.rs

@@ -551,11 +551,17 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
 
             // First search in functions lib (can override built-in)
             // Cater for both normal function call style and method call style (one additional arguments)
-            if state.lib.iter_fn().find(|(_, _, _, f)| {
+            #[cfg(not(feature = "no_function"))]
+            let has_script_fn = state.lib.iter_fn().find(|(_, _, _, f)| {
                 if !f.is_script() { return false; }
                 let fn_def = f.get_fn_def();
                 &fn_def.name == name && (args.len()..=args.len() + 1).contains(&fn_def.params.len())
-            }).is_some() {
+            }).is_some();
+
+            #[cfg(feature = "no_function")]
+            const has_script_fn: bool = false;
+
+            if has_script_fn {
                 // A script-defined function overrides the built-in function - do not make the call
                 x.3 = x.3.into_iter().map(|a| optimize_expr(a, state)).collect();
                 return Expr::FnCall(x);