Merge pull request #188 from schungx/master

Anonymous functions, no-std fix, simplify custom syntax, minor speed improvements.

Cargo.toml

@@ -46,10 +46,12 @@ codegen-units = 1
 
 [dependencies.libm]
 version = "0.2.1"
+default_features = false
 optional = true
 
 [dependencies.core-error]
 version = "0.0.0"
+default_features = false
 features = ["alloc"]
 optional = true
 
@@ -66,9 +68,9 @@ features = ["compile-time-rng"]
 optional = true
 
 [dependencies.serde]
-package = "serde"
 version = "1.0.111"
-features = ["derive"]
+default_features = false
+features = ["derive", "alloc"]
 optional = true
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

RELEASES.md

@@ -4,12 +4,22 @@ Rhai Release Notes
 Version 0.18.0
 ==============
 
+This version adds:
+
+* Anonymous functions (in closure syntax).  Simplifies creation of ad hoc functions.
+
 New features
 ------------
 
 * `call` can now be called function-call style for function pointers - this is to handle builds with `no_object`.
 * Disallow many keywords as variables, such as `print`, `eval`, `call`, `this` etc.
 * `x.call(f, ...)` allows binding `x` to `this` for the function referenced by the function pointer `f`.
+* Anonymous functions in the syntax of a closure, e.g. `|x, y, z| x + y - z`.
+
+Breaking changes
+----------------
+
+* Function signature for defining custom syntax is simplified.
 
 
 Version 0.17.0

doc/src/SUMMARY.md

@@ -75,6 +75,7 @@ The Rhai Scripting Language
        2. [Overloading](language/overload.md)
        3. [Namespaces](language/fn-namespaces.md)
        4. [Function Pointers](language/fn-ptr.md)
+       5. [Anonymous Functions](language/fn-anon.md)
    15. [Print and Debug](language/print-debug.md)
    16. [Modules](language/modules/index.md)
        1. [Export Variables, Functions and Sub-Modules](language/modules/export.md)

doc/src/about/non-design.md

@@ -25,12 +25,12 @@ It doesn't attempt to be a new language. For example:
 * No closures - do your closure magic in Rust instead; [turn a Rhai scripted function into a Rust closure]({{rootUrl}}/engine/call-fn.md).
 
 * No byte-codes/JIT - Rhai has an AST-walking interpreter which will not win any speed races. The purpose of Rhai is not
-  to be extremely _fast_, but to make it as easy as possible to integrate with native Rust programs.
+  to be extremely _fast_, but to make it as easy as possible to integrate with native Rust applications.
 
 Due to this intended usage, Rhai deliberately keeps the language simple and small by omitting advanced language features
 such as classes, inheritance, first-class functions, closures, concurrency, byte-codes, JIT etc.
 
-Avoid the temptation to write full-fledge program logic entirely in Rhai - that use case is best fulfilled by
+Avoid the temptation to write full-fledge application logic entirely in Rhai - that use case is best fulfilled by
 more complete languages such as JavaScript or Lua.
 
 Therefore, in actual practice, it is usually best to expose a Rust API into Rhai for scripts to call.

doc/src/engine/custom-syntax.md

@@ -126,32 +126,21 @@ Any custom syntax must include an _implementation_ of it.
 The function signature of an implementation is:
 
 ```rust
-Fn(
-    engine: &Engine,
-    scope: &mut Scope,
-    mods: &mut Imports,
-    state: &mut State,
-    lib: &Module,
-    this_ptr: &mut Option<&mut Dynamic>,
-    inputs: &[Expression],
-    level: usize
-) -> Result<Dynamic, Box<EvalAltResult>>
+Fn(engine: &Engine, context: &mut EvalContext, scope: &mut Scope, inputs: &[Expression])
+    -> Result<Dynamic, Box<EvalAltResult>>
 ```
 
 where:
 
-* `engine : &Engine` - reference to the current [`Engine`].
-* `scope : &mut Scope` - mutable reference to the current [`Scope`]; variables can be added to it.
-* `mods : &mut Imports` - mutable reference to the current collection of imported [`Module`]'s; **do not touch**.
-* `state : &mut State` - mutable reference to the current evaluation state; **do not touch**.
-* `lib : &Module` - reference to the current collection of script-defined functions.
-* `this_ptr : &mut Option<&mut Dynamic>` - mutable reference to the current binding of the `this` pointer; **do not touch**.
-* `inputs : &[Expression]` - a list of input expression trees.
-* `level : usize` - the current function call level.
+* `engine: &Engine` - reference to the current [`Engine`].
+* `context: &mut EvalContext` - mutable reference to the current evaluation _context_; **do not touch**.
+* `scope: &mut Scope` - mutable reference to the current [`Scope`]; variables can be added to it.
+* `inputs: &[Expression]` - a list of input expression trees.
 
-There are a lot of parameters, most of which should not be touched or Bad Things Happen™.
-They represent the running _content_ of a script evaluation and should simply be passed
-straight-through the the [`Engine`].
+#### WARNING - Lark's Vomit
+
+The `context` parameter contains the evaluation _context_ and should not be touched or Bad Things Happen™.
+It should simply be passed straight-through the the [`Engine`].
 
 ### Access Arguments
 
@@ -172,7 +161,7 @@ Use the `engine::eval_expression_tree` method to evaluate an expression tree.
 
 ```rust
 let expr = inputs.get(0).unwrap();
-let result = engine.eval_expression_tree(scope, mods, state, lib, this_ptr, expr, level)?;
+let result = engine.eval_expression_tree(context, scope, expr)?;
 ```
 
 As can be seem above, most arguments are simply passed straight-through to `engine::eval_expression_tree`.
@@ -210,13 +199,9 @@ The syntax is passed simply as a slice of `&str`.
 // Custom syntax implementation
 fn implementation_func(
     engine: &Engine,
+    context: &mut EvalContext,
     scope: &mut Scope,
-    mods: &mut Imports,
-    state: &mut State,
-    lib: &Module,
-    this_ptr: &mut Option<&mut Dynamic>,
-    inputs: &[Expression],
-    level: usize
+    inputs: &[Expression]
 ) -> Result<Dynamic, Box<EvalAltResult>> {
     let var_name = inputs[0].get_variable_name().unwrap().to_string();
     let stmt = inputs.get(1).unwrap();
@@ -227,15 +212,12 @@ fn implementation_func(
 
     loop {
         // Evaluate the statement block
-        engine.eval_expression_tree(scope, mods, state, lib, this_ptr, stmt, level)?;
+        engine.eval_expression_tree(context, scope, stmt)?;
 
         // Evaluate the condition expression
-        let stop = !engine
-            .eval_expression_tree(scope, mods, state, lib, this_ptr, condition, level)?
-            .as_bool()
-            .map_err(|_| EvalAltResult::ErrorBooleanArgMismatch(
-                "do-while".into(), expr.position()
-            ))?;
+        let stop = !engine.eval_expression_tree(context, scope, condition)?
+                          .as_bool().map_err(|_| EvalAltResult::ErrorBooleanArgMismatch(
+                                                    "do-while".into(), expr.position()))?;
 
         if stop {
             break;

doc/src/engine/raw.md

@@ -7,7 +7,7 @@ Raw `Engine`
 `Engine::new` creates a scripting [`Engine`] with common functionalities (e.g. printing to the console via `print`).
 
 In many controlled embedded environments, however, these may not be needed and unnecessarily occupy
-program code storage space.
+application code storage space.
 
 Use `Engine::new_raw` to create a _raw_ `Engine`, in which only a minimal set of
 basic arithmetic and logical operators are supported.

doc/src/language/fn-anon.md

@@ -0,0 +1,57 @@
+Anonymous Functions
+===================
+
+{{#include ../links.md}}
+
+Sometimes it gets tedious to define separate functions only to dispatch them via single [function pointers].
+This scenario is especially common when simulating object-oriented programming ([OOP]).
+
+```rust
+// Define object
+let obj = #{
+    data: 42,
+    increment: Fn("inc_obj"),   // use function pointers to
+    decrement: Fn("dec_obj"),   // refer to method functions
+    print: Fn("print_obj")
+};
+
+// Define method functions one-by-one
+fn inc_obj(x) { this.data += x; }
+fn dec_obj(x) { this.data -= x; }
+fn print_obj() { print(this.data); }
+```
+
+The above can be replaced by using _anonymous functions_ which have the same syntax as Rust's closures
+(but they are **NOT** closures, merely syntactic sugar):
+
+```rust
+let obj = #{
+    data: 42,
+    increment: |x| this.data += x,          // one-liner
+    decrement: |x| this.data -= x,
+    print_obj: || { print(this.data); }     // full function body
+};
+```
+
+The anonymous functions will be hoisted into separate functions in the global namespace.
+The above is equivalent to:
+
+```rust
+let obj = #{
+    data: 42,
+    increment: Fn("anon_fn_1000"),
+    decrement: Fn("anon_fn_1001"),
+    print: Fn("anon_fn_1002")
+};
+
+fn anon_fn_1000(x) { this.data += x; }
+fn anon_fn_1001(x) { this.data -= x; }
+fn anon_fn_1002() { print this.data; }
+```
+
+WARNING - NOT Closures
+----------------------
+
+Remember: anonymous functions, though having the same syntax as Rust _closures_, are themselves
+**not** closures.  In particular, they do not capture their running environment.  They are more like
+Rust's function pointers.

doc/src/language/fn-ptr.md

@@ -163,4 +163,4 @@ x == 42;
 Beware that this only works for _method-call_ style.  Normal function-call style cannot bind
 the `this` pointer (for syntactic reasons).
 
-Therefore, obviously, binding the `this` pointer is unsupported under [`no_function`].
+Therefore, obviously, binding the `this` pointer is unsupported under [`no_object`].

doc/src/language/object-maps-oop.md

@@ -20,17 +20,21 @@ to the [object map] before the function is called.  There is no way to simulate
 via a normal function-call syntax because all scripted function arguments are passed by value.
 
 ```rust
-fn do_action(x) { print(this.data + x); }   // 'this' binds to the object when called
+fn do_action(x) { this.data += x; }          // 'this' binds to the object when called
 
 let obj = #{
                 data: 40,
                 action: Fn("do_action")      // 'action' holds a function pointer to 'do_action'
            };
 
-obj.action(2);                              // Short-hand syntax: prints 42
+obj.action(2);                               // Calls 'do_action' with `this` bound to 'obj'
 
-// To achieve the above with normal function pointer calls:
-fn do_action(map, x) { print(map.data + x); }
+obj.call(obj.action, 2);                     // The above de-sugars to this
 
-obj.action.call(obj, 2);                    // this call cannot mutate 'obj'
+obj.data == 42;
+
+// To achieve the above with normal function pointer call will fail.
+fn do_action(map, x) { map.data += x; }      // 'map' is a copy
+
+obj.action.call(obj, 2);                     // 'obj' is passed as a copy by value
 ```

doc/src/language/oop.md

@@ -17,24 +17,23 @@ Rhai's [object maps] has [special support for OOP]({{rootUrl}}/language/object-m
 | [Object map] properties holding values                | properties  |
 | [Object map] properties that hold [function pointers] |   methods   |
 
+When a property of an [object map] is called like a method function, and if it happens to hold
+a valid [function pointer] (perhaps defined via an [anonymous function]), then the call will be
+dispatched to the actual function with `this` binding to the [object map] itself.
 
 Examples
 --------
 
 ```rust
 // Define the object
-let obj = #{
+let obj =
+     #{
           data: 0,
-                increment: Fn("add"),       // when called, 'this' binds to 'obj'
-                update: Fn("update"),       // when called, 'this' binds to 'obj'
-                action: Fn("action")        // when called, 'this' binds to 'obj'
+          increment: |x| this.data += x,    // when called, 'this' binds to 'obj'
+          update: |x| this.data = x,        // when called, 'this' binds to 'obj'
+          action: || print(this.data)       // when called, 'this' binds to 'obj'
      };
 
-// Define functions
-fn add(x)       { this.data += x; }         // update using 'this'
-fn update(x)    { this.data = x; }          // update using 'this'
-fn action()     { print(this.data); }       // access properties of 'this'
-
 // Use the object
 obj.increment(1);
 obj.action();                               // prints 1

doc/src/links.md

@@ -78,6 +78,8 @@
 [function pointers]: {{rootUrl}}/language/fn-ptr.md
 [function namespace]: {{rootUrl}}/language/fn-namespaces.md
 [function namespaces]: {{rootUrl}}/language/fn-namespaces.md
+[anonymous function]: {{rootUrl}}/language/fn-anon.md
+[anonymous functions]: {{rootUrl}}/language/fn-anon.md
 
 [`Module`]: {{rootUrl}}/language/modules/index.md
 [module]: {{rootUrl}}/language/modules/index.md

doc/src/start/builds/no-std.md

@@ -13,3 +13,9 @@ Nightly Required
 ----------------
 
 Currently, [`no_std`] requires the nightly compiler due to the crates that it uses.
+
+
+Samples
+-------
+
+Check out the [`no-std` sample applications](../examples/rust.md#no-std-samples) for different operating environments.

doc/src/start/examples/rust.md

@@ -3,14 +3,13 @@ Rust Examples
 
 {{#include ../../links.md}}
 
-A number of examples can be found in the `examples` folder:
+A number of examples can be found in the `examples` directory:
 
 | Example                                                                                                                | Description                                                                                                                                   |
 | ---------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------- |
 | [`arrays_and_structs`](https://github.com/jonathandturner/rhai/tree/master/examples/arrays_and_structs.rs)             | Shows how to register a custom Rust type and using [arrays] on it.                                                                            |
 | [`custom_types_and_methods`](https://github.com/jonathandturner/rhai/tree/master/examples/custom_types_and_methods.rs) | Shows how to register a custom Rust type and methods for it.                                                                                  |
 | [`hello`](https://github.com/jonathandturner/rhai/tree/master/examples/hello.rs)                                       | Simple example that evaluates an expression and prints the result.                                                                            |
-| [`no_std`](https://github.com/jonathandturner/rhai/tree/master/examples/no_std.rs)                                     | Example to test out `no-std` builds.</br>The [`no_std`] feature is required to build in `no-std`.                                             |
 | [`reuse_scope`](https://github.com/jonathandturner/rhai/tree/master/examples/reuse_scope.rs)                           | Evaluates two pieces of code in separate runs, but using a common [`Scope`].                                                                  |
 | [`rhai_runner`](https://github.com/jonathandturner/rhai/tree/master/examples/rhai_runner.rs)                           | Runs each filename passed to it as a Rhai script.                                                                                             |
 | [`serde`](https://github.com/jonathandturner/rhai/tree/master/examples/serde.rs)                                       | Example to serialize and deserialize Rust types with [`serde`](https://crates.io/crates/serde).<br/>The [`serde`] feature is required to run. |
@@ -30,3 +29,22 @@ Examples can be run with the following command:
 ```bash
 cargo run --example {example_name}
 ```
+
+`no-std` Samples
+----------------
+
+To illustrate `no-std` builds, a number of sample applications are available under the `no_std` directory:
+
+| Sample                                                                                  | Description                                                                                           | Optimization |                     Allocator                     | Panics |
+| --------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------- | :----------: | :-----------------------------------------------: | :----: |
+| [`no_std_test`](https://github.com/jonathandturner/rhai/tree/master/no_std/no_std_test) | Bare-bones test application that evaluates a Rhai expression and sets the result as the return value. |     Size     | [`wee_alloc`](https://crates.io/crates/wee_alloc) | Abort  |
+
+`cargo run` cannot be used to run a `no-std` sample.  It must first be built:
+
+```bash
+cd no_std/no_std_test
+
+cargo +nightly build --release
+
+./target/release/no_std_test
+```

doc/src/start/examples/scripts.md

@@ -6,27 +6,27 @@ Example Scripts
 Language Feature Scripts
 -----------------------
 
-There are also a number of examples scripts that showcase Rhai's features, all in the `scripts` folder:
+There are also a number of examples scripts that showcase Rhai's features, all in the `scripts` directory:
 
 | Script                                                                                                   | Description                                                                                 |
-| -------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- |
+| -------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- |
 | [`array.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/array.rhai)                   | [Arrays]                                                                                    |
 | [`assignment.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/assignment.rhai)         | Variable declarations                                                                       |
 | [`comments.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/comments.rhai)             | Just comments                                                                               |
-| [`for1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/for1.rhai)                     | [`for`](#for-loop) loops                                                      |
-| [`for2.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/for2.rhai)                     | [`for`](#for-loop) loops on [arrays]                                          |
+| [`for1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/for1.rhai)                     | [`for`]({{rootUrl}}/language/for.md) loops                                                  |
+| [`for2.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/for2.rhai)                     | [`for`]({{rootUrl}}/language/for.md) loops on [arrays]                                      |
 | [`function_decl1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/function_decl1.rhai) | A [function] without parameters                                                             |
 | [`function_decl2.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/function_decl2.rhai) | A [function] with two parameters                                                            |
 | [`function_decl3.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/function_decl3.rhai) | A [function] with many parameters                                                           |
-| [`if1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/if1.rhai)                       | [`if`](#if-statement) example                                                 |
-| [`loop.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/loop.rhai)                     | Count-down [`loop`](#infinite-loop) in Rhai, emulating a `do` .. `while` loop |
+| [`if1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/if1.rhai)                       | [`if`]({{rootUrl}}/language/if.md) example                                                  |
+| [`loop.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/loop.rhai)                     | Count-down [`loop`]({{rootUrl}}/language/loop.md) in Rhai, emulating a `do` .. `while` loop |
 | [`oop.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/oop.rhai)                       | Simulate [object-oriented programming (OOP)][OOP]                                           |
 | [`op1.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/op1.rhai)                       | Just simple addition                                                                        |
 | [`op2.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/op2.rhai)                       | Simple addition and multiplication                                                          |
 | [`op3.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/op3.rhai)                       | Change evaluation order with parenthesis                                                    |
 | [`string.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/string.rhai)                 | [String] operations                                                                         |
 | [`strings_map.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/strings_map.rhai)       | [String] and [object map] operations                                                        |
-| [`while.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/while.rhai)                   | [`while`](#while-loop) loop                                                   |
+| [`while.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/while.rhai)                   | [`while`]({{rootUrl}}/language/while.md) loop                                               |
 
 
 Benchmark Scripts
@@ -35,8 +35,8 @@ Benchmark Scripts
 The following scripts are for benchmarking the speed of Rhai:
 
 | Scripts                                                                                          | Description                                                                             |
-| ------------------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------- |
-| [`speed_test.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/speed_test.rhai) | A simple program to measure the speed of Rhai's interpreter (1 million iterations). |
+| ------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------- |
+| [`speed_test.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/speed_test.rhai) | A simple application to measure the speed of Rhai's interpreter (1 million iterations). |
 | [`primes.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/primes.rhai)         | Use Sieve of Eratosthenes to find all primes smaller than a limit.                      |
 | [`fibonacci.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/fibonacci.rhai)   | Calculate the n-th Fibonacci number using a really dumb algorithm.                      |
 | [`mat_mul.rhai`](https://github.com/jonathandturner/rhai/tree/master/scripts/mat_mul.rhai)       | Matrix multiplication test to measure the speed of multi-dimensional array access.      |
@@ -45,7 +45,7 @@ The following scripts are for benchmarking the speed of Rhai:
 Running Example Scripts
 ----------------------
 
-To run the scripts, either make a tiny program or use of the `rhai_runner` example:
+The [`rhai_runner`](../examples/rust.md) example can be used to run the scripts:
 
 ```bash
 cargo run --example rhai_runner scripts/any_script.rhai

examples/no_std.rs

@@ -1,23 +0,0 @@
-#![cfg_attr(feature = "no_std", no_std)]
-
-use rhai::{Engine, EvalAltResult, INT};
-
-#[cfg(feature = "no_std")]
-extern crate alloc;
-
-#[cfg(feature = "no_std")]
-use alloc::boxed::Box;
-
-fn main() -> Result<(), Box<EvalAltResult>> {
-    let engine = Engine::new();
-
-    let result = engine.eval::<INT>("40 + 2")?;
-
-    #[cfg(not(feature = "no_std"))]
-    println!("Answer: {}", result);
-
-    #[cfg(feature = "no_std")]
-    assert_eq!(result, 42);
-
-    Ok(())
-}

no_std/no_std_test/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "no_std_test"
+version = "0.1.0"
+edition = "2018"
+authors = ["Stephen Chung"]
+description = "no-std test application"
+homepage = "https://github.com/jonathandturner/rhai/tree/master/no_std/no_std_test"
+repository = "https://github.com/jonathandturner/rhai"
+
+[dependencies]
+rhai = { path = "../../", features = [ "no_std", "unchecked", "only_i32", "no_module" ], default_features = false }
+wee_alloc = { version = "0.4.5", default_features = false }
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+opt-level = "z"             # optimize for size
+debug = false
+rpath = false
+lto = "fat"
+debug-assertions = false
+codegen-units = 1
+panic = "abort"

no_std/no_std_test/README.md

@@ -0,0 +1,18 @@
+`no-std` Test Sample
+====================
+
+This sample application is a bare-bones `no-std` build for testing.
+
+[`wee_alloc`](https://crates.io/crates/wee_alloc) is used as the allocator.
+
+
+To Compile
+----------
+
+The nightly compiler is required:
+
+```bash
+cargo +nightly build --release
+```
+
+The release build is optimized for size.  It can be changed to optimize on speed instead.

no_std/no_std_test/src/main.rs

@@ -0,0 +1,43 @@
+//! This is a bare-bones `no-std` application that evaluates
+//! a simple expression and uses the result as the return value.
+
+#![no_std]
+#![feature(alloc_error_handler, start, core_intrinsics, lang_items)]
+
+extern crate alloc;
+extern crate wee_alloc;
+
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+use rhai::{Engine, INT};
+
+#[start]
+fn main(_argc: isize, _argv: *const *const u8) -> isize {
+    // Notice that this is a _raw_ engine.
+    // To do anything useful, load a few packages from `rhai::packages`.
+    let engine = Engine::new_raw();
+
+    // Evaluate a simple expression: 40 + 2
+    engine.eval_expression::<INT>("40 + 2").unwrap() as isize
+}
+
+#[alloc_error_handler]
+fn foo(_: core::alloc::Layout) -> ! {
+    core::intrinsics::abort();
+}
+
+#[panic_handler]
+#[lang = "panic_impl"]
+extern "C" fn rust_begin_panic(_: &core::panic::PanicInfo) -> ! {
+    core::intrinsics::abort();
+}
+
+#[lang = "eh_personality"]
+extern "C" fn eh_personality() {}
+
+#[no_mangle]
+extern "C" fn rust_eh_register_frames() {}
+
+#[no_mangle]
+extern "C" fn rust_eh_unregister_frames() {}

src/any.rs

@@ -203,6 +203,7 @@ impl Dynamic {
 }
 
 /// Map the name of a standard type into a friendly form.
+#[inline]
 pub(crate) fn map_std_type_name(name: &str) -> &str {
     if name == type_name::<String>() {
         "string"
@@ -243,12 +244,15 @@ impl fmt::Display for Dynamic {
             #[cfg(not(feature = "no_index"))]
             Union::Array(value) => fmt::Debug::fmt(value, f),
             #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => write!(f, "#{:?}", value),
+            Union::Map(value) => {
+                f.write_str("#")?;
+                fmt::Debug::fmt(value, f)
+            }
             Union::FnPtr(value) => fmt::Display::fmt(value, f),
 
             #[cfg(not(feature = "no_std"))]
             Union::Variant(value) if value.is::<Instant>() => write!(f, "<timestamp>"),
-            Union::Variant(_) => write!(f, "?"),
+            Union::Variant(value) => write!(f, "{}", (*value).type_name()),
         }
     }
 }
@@ -266,12 +270,15 @@ impl fmt::Debug for Dynamic {
             #[cfg(not(feature = "no_index"))]
             Union::Array(value) => fmt::Debug::fmt(value, f),
             #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => write!(f, "#{:?}", value),
+            Union::Map(value) => {
+                f.write_str("#")?;
+                fmt::Debug::fmt(value, f)
+            }
             Union::FnPtr(value) => fmt::Display::fmt(value, f),
 
             #[cfg(not(feature = "no_std"))]
             Union::Variant(value) if value.is::<Instant>() => write!(f, "<timestamp>"),
-            Union::Variant(_) => write!(f, "<dynamic>"),
+            Union::Variant(value) => write!(f, "{}", (*value).type_name()),
         }
     }
 }
@@ -334,30 +341,47 @@ impl Dynamic {
     /// assert_eq!(new_result.type_name(), "string");
     /// assert_eq!(new_result.to_string(), "hello");
     /// ```
+    #[inline(always)]
     pub fn from<T: Variant + Clone>(value: T) -> Self {
-        if let Some(result) = <dyn Any>::downcast_ref::<()>(&value) {
-            return result.clone().into();
-        } else if let Some(result) = <dyn Any>::downcast_ref::<bool>(&value) {
-            return result.clone().into();
-        } else if let Some(result) = <dyn Any>::downcast_ref::<INT>(&value) {
-            return result.clone().into();
-        } else if let Some(result) = <dyn Any>::downcast_ref::<char>(&value) {
-            return result.clone().into();
-        } else if let Some(result) = <dyn Any>::downcast_ref::<ImmutableString>(&value) {
-            return result.clone().into();
-        }
+        let type_id = TypeId::of::<T>();
 
+        if type_id == TypeId::of::<INT>() {
+            return <dyn Any>::downcast_ref::<INT>(&value)
+                .unwrap()
+                .clone()
+                .into();
+        }
         #[cfg(not(feature = "no_float"))]
-        if let Some(result) = <dyn Any>::downcast_ref::<FLOAT>(&value) {
-            return result.clone().into();
+        if type_id == TypeId::of::<FLOAT>() {
+            return <dyn Any>::downcast_ref::<FLOAT>(&value)
+                .unwrap()
+                .clone()
+                .into();
+        }
+        if type_id == TypeId::of::<bool>() {
+            return <dyn Any>::downcast_ref::<bool>(&value)
+                .unwrap()
+                .clone()
+                .into();
+        }
+        if type_id == TypeId::of::<char>() {
+            return <dyn Any>::downcast_ref::<char>(&value)
+                .unwrap()
+                .clone()
+                .into();
+        }
+        if type_id == TypeId::of::<ImmutableString>() {
+            return <dyn Any>::downcast_ref::<ImmutableString>(&value)
+                .unwrap()
+                .clone()
+                .into();
+        }
+        if type_id == TypeId::of::<()>() {
+            return ().into();
         }
 
         let mut boxed = Box::new(value);
 
-        boxed = match unsafe_cast_box::<_, Dynamic>(boxed) {
-            Ok(d) => return *d,
-            Err(val) => val,
-        };
         boxed = match unsafe_cast_box::<_, String>(boxed) {
             Ok(s) => return (*s).into(),
             Err(val) => val,
@@ -378,6 +402,11 @@ impl Dynamic {
             }
         }
 
+        boxed = match unsafe_cast_box::<_, Dynamic>(boxed) {
+            Ok(d) => return *d,
+            Err(val) => val,
+        };
+
         Self(Union::Variant(Box::new(boxed)))
     }
 
@@ -395,30 +424,80 @@ impl Dynamic {
     ///
     /// assert_eq!(x.try_cast::<u32>().unwrap(), 42);
     /// ```
+    #[inline(always)]
     pub fn try_cast<T: Variant>(self) -> Option<T> {
         let type_id = TypeId::of::<T>();
 
+        if type_id == TypeId::of::<INT>() {
+            return match self.0 {
+                Union::Int(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_float"))]
+        if type_id == TypeId::of::<FLOAT>() {
+            return match self.0 {
+                Union::Float(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<bool>() {
+            return match self.0 {
+                Union::Bool(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<ImmutableString>() {
+            return match self.0 {
+                Union::Str(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<String>() {
+            return match self.0 {
+                Union::Str(value) => unsafe_try_cast(value.into_owned()),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<char>() {
+            return match self.0 {
+                Union::Char(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_index"))]
+        if type_id == TypeId::of::<Array>() {
+            return match self.0 {
+                Union::Array(value) => unsafe_cast_box::<_, T>(value).ok().map(|v| *v),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_object"))]
+        if type_id == TypeId::of::<Map>() {
+            return match self.0 {
+                Union::Map(value) => unsafe_cast_box::<_, T>(value).ok().map(|v| *v),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<FnPtr>() {
+            return match self.0 {
+                Union::FnPtr(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<()>() {
+            return match self.0 {
+                Union::Unit(value) => unsafe_try_cast(value),
+                _ => None,
+            };
+        }
         if type_id == TypeId::of::<Dynamic>() {
             return unsafe_cast_box::<_, T>(Box::new(self)).ok().map(|v| *v);
         }
 
         match self.0 {
-            Union::Unit(value) => unsafe_try_cast(value),
-            Union::Bool(value) => unsafe_try_cast(value),
-            Union::Str(value) if type_id == TypeId::of::<ImmutableString>() => {
-                unsafe_try_cast(value)
-            }
-            Union::Str(value) => unsafe_try_cast(value.into_owned()),
-            Union::Char(value) => unsafe_try_cast(value),
-            Union::Int(value) => unsafe_try_cast(value),
-            #[cfg(not(feature = "no_float"))]
-            Union::Float(value) => unsafe_try_cast(value),
-            #[cfg(not(feature = "no_index"))]
-            Union::Array(value) => unsafe_cast_box::<_, T>(value).ok().map(|v| *v),
-            #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => unsafe_cast_box::<_, T>(value).ok().map(|v| *v),
-            Union::FnPtr(value) => unsafe_try_cast(value),
             Union::Variant(value) => (*value).as_box_any().downcast().map(|x| *x).ok(),
+            _ => None,
         }
     }
 
@@ -438,81 +517,162 @@ impl Dynamic {
     ///
     /// assert_eq!(x.cast::<u32>(), 42);
     /// ```
+    #[inline(always)]
     pub fn cast<T: Variant + Clone>(self) -> T {
-        let type_id = TypeId::of::<T>();
-
-        if type_id == TypeId::of::<Dynamic>() {
-            return *unsafe_cast_box::<_, T>(Box::new(self)).unwrap();
-        }
-
-        match self.0 {
-            Union::Unit(value) => unsafe_try_cast(value).unwrap(),
-            Union::Bool(value) => unsafe_try_cast(value).unwrap(),
-            Union::Str(value) if type_id == TypeId::of::<ImmutableString>() => {
-                unsafe_try_cast(value).unwrap()
-            }
-            Union::Str(value) => unsafe_try_cast(value.into_owned()).unwrap(),
-            Union::Char(value) => unsafe_try_cast(value).unwrap(),
-            Union::Int(value) => unsafe_try_cast(value).unwrap(),
-            #[cfg(not(feature = "no_float"))]
-            Union::Float(value) => unsafe_try_cast(value).unwrap(),
-            #[cfg(not(feature = "no_index"))]
-            Union::Array(value) => *unsafe_cast_box::<_, T>(value).unwrap(),
-            #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => *unsafe_cast_box::<_, T>(value).unwrap(),
-            Union::FnPtr(value) => unsafe_try_cast(value).unwrap(),
-            Union::Variant(value) => (*value).as_box_any().downcast().map(|x| *x).unwrap(),
-        }
+        self.try_cast::<T>().unwrap()
     }
 
     /// Get a reference of a specific type to the `Dynamic`.
     /// Casting to `Dynamic` just returns a reference to it.
     /// Returns `None` if the cast fails.
+    #[inline(always)]
     pub fn downcast_ref<T: Variant + Clone>(&self) -> Option<&T> {
-        if TypeId::of::<T>() == TypeId::of::<Dynamic>() {
+        let type_id = TypeId::of::<T>();
+
+        if type_id == TypeId::of::<INT>() {
+            return match &self.0 {
+                Union::Int(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_float"))]
+        if type_id == TypeId::of::<FLOAT>() {
+            return match &self.0 {
+                Union::Float(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<bool>() {
+            return match &self.0 {
+                Union::Bool(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<ImmutableString>() {
+            return match &self.0 {
+                Union::Str(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<String>() {
+            return match &self.0 {
+                Union::Str(value) => <dyn Any>::downcast_ref::<T>(value.as_ref()),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<char>() {
+            return match &self.0 {
+                Union::Char(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_index"))]
+        if type_id == TypeId::of::<Array>() {
+            return match &self.0 {
+                Union::Array(value) => <dyn Any>::downcast_ref::<T>(value.as_ref()),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_object"))]
+        if type_id == TypeId::of::<Map>() {
+            return match &self.0 {
+                Union::Map(value) => <dyn Any>::downcast_ref::<T>(value.as_ref()),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<FnPtr>() {
+            return match &self.0 {
+                Union::FnPtr(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<()>() {
+            return match &self.0 {
+                Union::Unit(value) => <dyn Any>::downcast_ref::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<Dynamic>() {
             return <dyn Any>::downcast_ref::<T>(self);
         }
 
         match &self.0 {
-            Union::Unit(value) => <dyn Any>::downcast_ref::<T>(value),
-            Union::Bool(value) => <dyn Any>::downcast_ref::<T>(value),
-            Union::Str(value) => <dyn Any>::downcast_ref::<T>(value)
-                .or_else(|| <dyn Any>::downcast_ref::<T>(value.as_ref())),
-            Union::Char(value) => <dyn Any>::downcast_ref::<T>(value),
-            Union::Int(value) => <dyn Any>::downcast_ref::<T>(value),
-            #[cfg(not(feature = "no_float"))]
-            Union::Float(value) => <dyn Any>::downcast_ref::<T>(value),
-            #[cfg(not(feature = "no_index"))]
-            Union::Array(value) => <dyn Any>::downcast_ref::<T>(value.as_ref()),
-            #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => <dyn Any>::downcast_ref::<T>(value.as_ref()),
-            Union::FnPtr(value) => <dyn Any>::downcast_ref::<T>(value),
             Union::Variant(value) => value.as_ref().as_ref().as_any().downcast_ref::<T>(),
+            _ => None,
         }
     }
 
     /// Get a mutable reference of a specific type to the `Dynamic`.
     /// Casting to `Dynamic` just returns a mutable reference to it.
     /// Returns `None` if the cast fails.
+    #[inline(always)]
     pub fn downcast_mut<T: Variant + Clone>(&mut self) -> Option<&mut T> {
-        if TypeId::of::<T>() == TypeId::of::<Dynamic>() {
+        let type_id = TypeId::of::<T>();
+
+        if type_id == TypeId::of::<INT>() {
+            return match &mut self.0 {
+                Union::Int(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_float"))]
+        if type_id == TypeId::of::<FLOAT>() {
+            return match &mut self.0 {
+                Union::Float(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<bool>() {
+            return match &mut self.0 {
+                Union::Bool(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<ImmutableString>() {
+            return match &mut self.0 {
+                Union::Str(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<char>() {
+            return match &mut self.0 {
+                Union::Char(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_index"))]
+        if type_id == TypeId::of::<Array>() {
+            return match &mut self.0 {
+                Union::Array(value) => <dyn Any>::downcast_mut::<T>(value.as_mut()),
+                _ => None,
+            };
+        }
+        #[cfg(not(feature = "no_object"))]
+        if type_id == TypeId::of::<Map>() {
+            return match &mut self.0 {
+                Union::Map(value) => <dyn Any>::downcast_mut::<T>(value.as_mut()),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<FnPtr>() {
+            return match &mut self.0 {
+                Union::FnPtr(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<()>() {
+            return match &mut self.0 {
+                Union::Unit(value) => <dyn Any>::downcast_mut::<T>(value),
+                _ => None,
+            };
+        }
+        if type_id == TypeId::of::<Dynamic>() {
             return <dyn Any>::downcast_mut::<T>(self);
         }
 
         match &mut self.0 {
-            Union::Unit(value) => <dyn Any>::downcast_mut::<T>(value),
-            Union::Bool(value) => <dyn Any>::downcast_mut::<T>(value),
-            Union::Str(value) => <dyn Any>::downcast_mut::<T>(value),
-            Union::Char(value) => <dyn Any>::downcast_mut::<T>(value),
-            Union::Int(value) => <dyn Any>::downcast_mut::<T>(value),
-            #[cfg(not(feature = "no_float"))]
-            Union::Float(value) => <dyn Any>::downcast_mut::<T>(value),
-            #[cfg(not(feature = "no_index"))]
-            Union::Array(value) => <dyn Any>::downcast_mut::<T>(value.as_mut()),
-            #[cfg(not(feature = "no_object"))]
-            Union::Map(value) => <dyn Any>::downcast_mut::<T>(value.as_mut()),
-            Union::FnPtr(value) => <dyn Any>::downcast_mut::<T>(value),
             Union::Variant(value) => value.as_mut().as_mut_any().downcast_mut::<T>(),
+            _ => None,
         }
     }
 

src/engine.rs

@@ -18,7 +18,7 @@ use crate::utils::StaticVec;
 use crate::parser::FLOAT;
 
 #[cfg(feature = "internals")]
-use crate::syntax::CustomSyntax;
+use crate::syntax::{CustomSyntax, EvalContext};
 
 use crate::stdlib::{
     any::{type_name, TypeId},
@@ -87,6 +87,7 @@ pub const FN_GET: &str = "get$";
 pub const FN_SET: &str = "set$";
 pub const FN_IDX_GET: &str = "index$get$";
 pub const FN_IDX_SET: &str = "index$set$";
+pub const FN_ANONYMOUS: &str = "anon$";
 
 #[cfg(feature = "internals")]
 pub const MARKER_EXPR: &str = "$expr$";
@@ -187,7 +188,7 @@ impl Target<'_> {
         }
     }
     /// Update the value of the `Target`.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     pub fn set_value(&mut self, new_val: Dynamic) -> Result<(), Box<EvalAltResult>> {
         match self {
             Self::Ref(r) => **r = new_val,
@@ -418,12 +419,9 @@ pub fn make_getter(id: &str) -> String {
 fn extract_prop_from_getter(fn_name: &str) -> Option<&str> {
     #[cfg(not(feature = "no_object"))]
     if fn_name.starts_with(FN_GET) {
-        Some(&fn_name[FN_GET.len()..])
-    } else {
-        None
+        return Some(&fn_name[FN_GET.len()..]);
     }
 
-    #[cfg(feature = "no_object")]
     None
 }
 
@@ -436,12 +434,9 @@ pub fn make_setter(id: &str) -> String {
 fn extract_prop_from_setter(fn_name: &str) -> Option<&str> {
     #[cfg(not(feature = "no_object"))]
     if fn_name.starts_with(FN_SET) {
-        Some(&fn_name[FN_SET.len()..])
-    } else {
-        None
+        return Some(&fn_name[FN_SET.len()..]);
     }
 
-    #[cfg(feature = "no_object")]
     None
 }
 
@@ -453,7 +448,7 @@ fn default_print(s: &str) {
 }
 
 /// Search for a module within an imports stack.
-/// Position in `EvalAltResult` is None and must be set afterwards.
+/// Position in `EvalAltResult` is `None` and must be set afterwards.
 fn search_imports<'s>(
     mods: &'s Imports,
     state: &mut State,
@@ -486,7 +481,7 @@ fn search_imports<'s>(
 }
 
 /// Search for a module within an imports stack.
-/// Position in `EvalAltResult` is None and must be set afterwards.
+/// Position in `EvalAltResult` is `None` and must be set afterwards.
 fn search_imports_mut<'s>(
     mods: &'s mut Imports,
     state: &mut State,
@@ -636,7 +631,7 @@ impl Engine {
     }
 
     /// Universal method for calling functions either registered with the `Engine` or written in Rhai.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     ///
     /// ## WARNING
     ///
@@ -654,7 +649,7 @@ impl Engine {
         args: &mut FnCallArgs,
         is_ref: bool,
         is_method: bool,
-        def_val: Option<&Dynamic>,
+        def_val: Option<bool>,
         level: usize,
     ) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
         self.inc_operations(state)?;
@@ -709,7 +704,7 @@ impl Engine {
         /// This function restores the first argument that was replaced by `normalize_first_arg_of_method_call`.
         fn restore_first_arg<'a>(old_this_ptr: Option<&'a mut Dynamic>, args: &mut FnCallArgs<'a>) {
             if let Some(this_pointer) = old_this_ptr {
-                mem::replace(args.get_mut(0).unwrap(), this_pointer);
+                args[0] = this_pointer;
             }
         }
 
@@ -815,7 +810,7 @@ impl Engine {
 
         // Return default value (if any)
         if let Some(val) = def_val {
-            return Ok((val.clone(), false));
+            return Ok((val.into(), false));
         }
 
         // Getter function not found?
@@ -877,7 +872,7 @@ impl Engine {
     }
 
     /// Call a script-defined function.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     ///
     /// ## WARNING
     ///
@@ -959,7 +954,7 @@ impl Engine {
     }
 
     /// Perform an actual function call, taking care of special functions
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     ///
     /// ## WARNING
     ///
@@ -976,7 +971,7 @@ impl Engine {
         args: &mut FnCallArgs,
         is_ref: bool,
         is_method: bool,
-        def_val: Option<&Dynamic>,
+        def_val: Option<bool>,
         level: usize,
     ) -> Result<(Dynamic, bool), Box<EvalAltResult>> {
         // Qualifiers (none) + function name + number of arguments + argument `TypeId`'s.
@@ -1022,7 +1017,7 @@ impl Engine {
     }
 
     /// Evaluate a text string as a script - used primarily for 'eval'.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     fn eval_script_expr(
         &self,
         scope: &mut Scope,
@@ -1081,7 +1076,6 @@ impl Engine {
 
         let is_ref = target.is_ref();
         let is_value = target.is_value();
-        let def_val = def_val.as_ref();
 
         // Get a reference to the mutation target Dynamic
         let obj = target.as_mut();
@@ -1100,7 +1094,7 @@ impl Engine {
 
             // Map it to name(args) in function-call style
             self.exec_fn_call(
-                state, lib, fn_name, *native, hash, args, false, false, def_val, level,
+                state, lib, fn_name, *native, hash, args, false, false, *def_val, level,
             )
         } else if fn_name == KEYWORD_FN_PTR_CALL && idx.len() > 0 && idx[0].is::<FnPtr>() {
             // FnPtr call on object
@@ -1120,7 +1114,7 @@ impl Engine {
 
             // Map it to name(args) in function-call style
             self.exec_fn_call(
-                state, lib, &fn_name, *native, hash, args, is_ref, true, def_val, level,
+                state, lib, &fn_name, *native, hash, args, is_ref, true, *def_val, level,
             )
         } else {
             let redirected: Option<ImmutableString>;
@@ -1146,7 +1140,7 @@ impl Engine {
             let args = arg_values.as_mut();
 
             self.exec_fn_call(
-                state, lib, fn_name, *native, hash, args, is_ref, true, def_val, level,
+                state, lib, fn_name, *native, hash, args, is_ref, true, *def_val, level,
             )
         }
         .map_err(|err| err.new_position(*pos))?;
@@ -1161,7 +1155,7 @@ impl Engine {
     }
 
     /// Chain-evaluate a dot/index chain.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     fn eval_dot_index_chain_helper(
         &self,
         state: &mut State,
@@ -1210,14 +1204,14 @@ impl Engine {
                     }
                     // xxx[rhs] = new_val
                     _ if new_val.is_some() => {
+                        let mut new_val = new_val.unwrap();
                         let mut idx_val2 = idx_val.clone();
 
                         match self.get_indexed_mut(state, lib, target, idx_val, pos, true, level) {
                             // Indexed value is an owned value - the only possibility is an indexer
                             // Try to call an index setter
                             Ok(obj_ptr) if obj_ptr.is_value() => {
-                                let args =
-                                    &mut [target.as_mut(), &mut idx_val2, &mut new_val.unwrap()];
+                                let args = &mut [target.as_mut(), &mut idx_val2, &mut new_val];
 
                                 self.exec_fn_call(
                                     state, lib, FN_IDX_SET, true, 0, args, is_ref, true, None,
@@ -1236,17 +1230,13 @@ impl Engine {
                             // Indexed value is a reference - update directly
                             Ok(ref mut obj_ptr) => {
                                 obj_ptr
-                                    .set_value(new_val.unwrap())
+                                    .set_value(new_val)
                                     .map_err(|err| err.new_position(rhs.position()))?;
                             }
                             Err(err) => match *err {
                                 // No index getter - try to call an index setter
                                 EvalAltResult::ErrorIndexingType(_, _) => {
-                                    let args = &mut [
-                                        target.as_mut(),
-                                        &mut idx_val2,
-                                        &mut new_val.unwrap(),
-                                    ];
+                                    let args = &mut [target.as_mut(), &mut idx_val2, &mut new_val];
 
                                     self.exec_fn_call(
                                         state, lib, FN_IDX_SET, true, 0, args, is_ref, true, None,
@@ -1694,13 +1684,12 @@ impl Engine {
             #[cfg(not(feature = "no_index"))]
             Dynamic(Union::Array(mut rhs_value)) => {
                 let op = "==";
-                let def_value = false.into();
                 let mut scope = Scope::new();
 
                 // Call the `==` operator to compare each value
                 for value in rhs_value.iter_mut() {
+                    let def_value = Some(false);
                     let args = &mut [&mut lhs_value.clone(), value];
-                    let def_value = Some(&def_value);
 
                     let hashes = (
                         // Qualifiers (none) + function name + number of arguments + argument `TypeId`'s.
@@ -1749,15 +1738,19 @@ impl Engine {
     #[deprecated(note = "this method is volatile and may change")]
     pub fn eval_expression_tree(
         &self,
+        context: &mut EvalContext,
         scope: &mut Scope,
-        mods: &mut Imports,
-        state: &mut State,
-        lib: &Module,
-        this_ptr: &mut Option<&mut Dynamic>,
         expr: &Expression,
-        level: usize,
     ) -> Result<Dynamic, Box<EvalAltResult>> {
-        self.eval_expr(scope, mods, state, lib, this_ptr, expr.expr(), level)
+        self.eval_expr(
+            scope,
+            context.mods,
+            context.state,
+            context.lib,
+            context.this_ptr,
+            expr.expr(),
+            context.level,
+        )
     }
 
     /// Evaluate an expression
@@ -1782,9 +1775,10 @@ impl Engine {
             Expr::FloatConstant(x) => Ok(x.0.into()),
             Expr::StringConstant(x) => Ok(x.0.to_string().into()),
             Expr::CharConstant(x) => Ok(x.0.into()),
+            Expr::FnPointer(x) => Ok(FnPtr::new_unchecked(x.0.clone()).into()),
             Expr::Variable(x) if (x.0).0 == KEYWORD_THIS => {
-                if let Some(ref val) = this_ptr {
-                    Ok((*val).clone())
+                if let Some(val) = this_ptr {
+                    Ok(val.clone())
                 } else {
                     Err(Box::new(EvalAltResult::ErrorUnboundedThis((x.0).1)))
                 }
@@ -1839,15 +1833,16 @@ impl Engine {
                             // Not built in, map to `var = var op rhs`
                             let op = &op[..op.len() - 1]; // extract operator without =
                             let hash = calc_fn_hash(empty(), op, 2, empty());
+                            // Clone the LHS value
                             let args = &mut [&mut lhs_ptr.clone(), &mut rhs_val];
-
-                            // Set variable value
-                            *lhs_ptr = self
+                            // Run function
+                            let (value, _) = self
                                 .exec_fn_call(
                                     state, lib, op, true, hash, args, false, false, None, level,
                                 )
-                                .map(|(v, _)| v)
                                 .map_err(|err| err.new_position(*op_pos))?;
+                            // Set value to LHS
+                            *lhs_ptr = value;
                         }
                         Ok(Default::default())
                     }
@@ -1941,7 +1936,6 @@ impl Engine {
             // Normal function call
             Expr::FnCall(x) if x.1.is_none() => {
                 let ((name, native, pos), _, hash, args_expr, def_val) = x.as_ref();
-                let def_val = def_val.as_ref();
 
                 // Handle Fn()
                 if name == KEYWORD_FN_PTR && args_expr.len() == 1 {
@@ -2072,7 +2066,7 @@ impl Engine {
 
                 let args = args.as_mut();
                 self.exec_fn_call(
-                    state, lib, name, *native, hash, args, is_ref, false, def_val, level,
+                    state, lib, name, *native, hash, args, is_ref, false, *def_val, level,
                 )
                 .map(|(v, _)| v)
                 .map_err(|err| err.new_position(*pos))
@@ -2166,7 +2160,7 @@ impl Engine {
                         .map_err(|err| err.new_position(*pos)),
                     Err(err) => match *err {
                         EvalAltResult::ErrorFunctionNotFound(_, _) if def_val.is_some() => {
-                            Ok(def_val.clone().unwrap())
+                            Ok(def_val.unwrap().into())
                         }
                         EvalAltResult::ErrorFunctionNotFound(_, _) => {
                             Err(Box::new(EvalAltResult::ErrorFunctionNotFound(
@@ -2225,7 +2219,14 @@ impl Engine {
             Expr::Custom(x) => {
                 let func = (x.0).1.as_ref();
                 let ep: StaticVec<_> = (x.0).0.iter().map(|e| e.into()).collect();
-                func(self, scope, mods, state, lib, this_ptr, ep.as_ref(), level)
+                let mut context = EvalContext {
+                    mods,
+                    state,
+                    lib,
+                    this_ptr,
+                    level,
+                };
+                func(self, &mut context, scope, ep.as_ref())
             }
 
             _ => unreachable!(),
@@ -2502,12 +2503,8 @@ impl Engine {
                 for ((id, id_pos), rename) in list.iter() {
                     // Mark scope variables as public
                     if let Some(index) = scope.get_index(id).map(|(i, _)| i) {
-                        let alias = rename
-                            .as_ref()
-                            .map(|(n, _)| n.clone())
-                            .unwrap_or_else(|| id.clone());
-
-                        scope.set_entry_alias(index, alias);
+                        let alias = rename.as_ref().map(|(n, _)| n).unwrap_or_else(|| id);
+                        scope.set_entry_alias(index, alias.clone());
                     } else {
                         return Err(Box::new(EvalAltResult::ErrorVariableNotFound(
                             id.into(),
@@ -2633,7 +2630,7 @@ impl Engine {
     }
 
     /// Check if the number of operations stay within limit.
-    /// Position in `EvalAltResult` is None and must be set afterwards.
+    /// Position in `EvalAltResult` is `None` and must be set afterwards.
     fn inc_operations(&self, state: &mut State) -> Result<(), Box<EvalAltResult>> {
         state.operations += 1;
 

src/error.rs

@@ -206,6 +206,9 @@ impl fmt::Display for ParseErrorType {
 
             Self::FnMissingParams(s) => write!(f, "Expecting parameters for function '{}'", s),
 
+            Self::FnMissingBody(s) if s.is_empty() => {
+                f.write_str("Expecting body statement block for anonymous function")
+            }
             Self::FnMissingBody(s) => {
                 write!(f, "Expecting body statement block for function '{}'", s)
             }

src/lib.rs

@@ -171,6 +171,10 @@ pub use parser::{CustomExpr, Expr, ReturnType, ScriptFnDef, Stmt};
 #[deprecated(note = "this type is volatile and may change")]
 pub use engine::{Expression, Imports, State as EvalState};
 
+#[cfg(feature = "internals")]
+#[deprecated(note = "this type is volatile and may change")]
+pub use syntax::EvalContext;
+
 #[cfg(feature = "internals")]
 #[deprecated(note = "this type is volatile and may change")]
 pub use module::ModuleRef;

src/module.rs

@@ -30,6 +30,7 @@ use crate::stdlib::{
 };
 
 #[cfg(not(feature = "no_std"))]
+#[cfg(feature = "sync")]
 use crate::stdlib::sync::RwLock;
 
 /// Return type of module-level Rust function.
@@ -1098,7 +1099,7 @@ impl Module {
 ///
 /// A `StaticVec` is used because most module-level access contains only one level,
 /// and it is wasteful to always allocate a `Vec` with one element.
-#[derive(Clone, Eq, PartialEq, Default)]
+#[derive(Clone, Eq, PartialEq, Default, Hash)]
 pub struct ModuleRef(StaticVec<(String, Position)>, Option<NonZeroUsize>);
 
 impl fmt::Debug for ModuleRef {

src/optimize.rs

@@ -1,9 +1,12 @@
 use crate::any::Dynamic;
 use crate::calc_fn_hash;
-use crate::engine::{Engine, Imports, KEYWORD_DEBUG, KEYWORD_EVAL, KEYWORD_PRINT, KEYWORD_TYPE_OF};
+use crate::engine::{
+    Engine, Imports, KEYWORD_DEBUG, KEYWORD_EVAL, KEYWORD_FN_PTR, KEYWORD_PRINT, KEYWORD_TYPE_OF,
+};
 use crate::module::Module;
 use crate::parser::{map_dynamic_to_expr, Expr, ReturnType, ScriptFnDef, Stmt, AST};
 use crate::scope::{Entry as ScopeEntry, EntryType as ScopeEntryType, Scope};
+use crate::token::is_valid_identifier;
 use crate::utils::StaticVec;
 
 #[cfg(feature = "internals")]
@@ -397,7 +400,7 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
                 // All other items can be thrown away.
                 state.set_dirty();
                 let pos = m.1;
-                m.0.into_iter().find(|((name, _), _)| name.as_str() == prop)
+                m.0.into_iter().find(|((name, _), _)| name.as_str() == prop.as_str())
                     .map(|(_, expr)| expr.set_position(pos))
                     .unwrap_or_else(|| Expr::Unit(pos))
             }
@@ -431,7 +434,7 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
             (Expr::StringConstant(s), Expr::IntegerConstant(i)) if i.0 >= 0 && (i.0 as usize) < s.0.chars().count() => {
                 // String literal indexing - get the character
                 state.set_dirty();
-                Expr::CharConstant(Box::new((s.0.chars().nth(i.0 as usize).expect("should get char"), s.1)))
+                Expr::CharConstant(Box::new((s.0.chars().nth(i.0 as usize).unwrap(), s.1)))
             }
             // lhs[rhs]
             (lhs, rhs) => Expr::Index(Box::new((optimize_expr(lhs, state), optimize_expr(rhs, state), x.2))),
@@ -528,6 +531,19 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
             Expr::FnCall(x)
         }
 
+        // Fn("...")
+        Expr::FnCall(x)
+            if x.1.is_none()
+            && (x.0).0 == KEYWORD_FN_PTR
+            && x.3.len() == 1
+            && matches!(x.3[0], Expr::StringConstant(_))
+        => {
+            match &x.3[0] {
+                Expr::StringConstant(s) if is_valid_identifier(s.0.chars()) => Expr::FnPointer(s.clone()),
+                _ => Expr::FnCall(x)
+            }
+        }
+
         // Eagerly call functions
         Expr::FnCall(mut x)
                 if x.1.is_none() // Non-qualified
@@ -571,7 +587,7 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
                         Some(arg_for_type_of.to_string().into())
                     } else {
                         // Otherwise use the default value, if any
-                        def_value.clone()
+                        def_value.map(|v| v.into())
                     }
                 })
                 .and_then(|result| map_dynamic_to_expr(result, *pos))
@@ -598,7 +614,7 @@ fn optimize_expr(expr: Expr, state: &mut State) -> Expr {
             state.set_dirty();
 
             // Replace constant with value
-            state.find_constant(&name).expect("should find constant in scope!").clone().set_position(pos)
+            state.find_constant(&name).unwrap().clone().set_position(pos)
         }
 
         // Custom syntax
@@ -639,10 +655,7 @@ fn optimize(
                 && expr.as_ref().map(|v| v.is_constant()).unwrap_or(false)
         })
         .for_each(|ScopeEntry { name, expr, .. }| {
-            state.push_constant(
-                name.as_ref(),
-                (**expr.as_ref().expect("should be Some(expr)")).clone(),
-            )
+            state.push_constant(name.as_ref(), expr.as_ref().unwrap().as_ref().clone())
         });
 
     let orig_constants_len = state.constants.len();

src/packages/arithmetic.rs

@@ -7,6 +7,10 @@ use crate::token::Position;
 #[cfg(not(feature = "no_float"))]
 use crate::parser::FLOAT;
 
+#[cfg(not(feature = "no_float"))]
+#[cfg(feature = "no_std")]
+use num_traits::*;
+
 use num_traits::{
     identities::Zero, CheckedAdd, CheckedDiv, CheckedMul, CheckedNeg, CheckedRem, CheckedShl,
     CheckedShr, CheckedSub,

src/packages/math_basic.rs

@@ -6,6 +6,10 @@ use crate::token::Position;
 #[cfg(not(feature = "no_float"))]
 use crate::parser::FLOAT;
 
+#[cfg(not(feature = "no_float"))]
+#[cfg(feature = "no_std")]
+use num_traits::*;
+
 use crate::stdlib::{boxed::Box, format, i32, i64};
 
 #[cfg(feature = "only_i32")]

src/parser.rs

@@ -2,7 +2,7 @@
 
 use crate::any::{Dynamic, Union};
 use crate::calc_fn_hash;
-use crate::engine::{make_getter, make_setter, Engine, KEYWORD_THIS};
+use crate::engine::{make_getter, make_setter, Engine, FN_ANONYMOUS, KEYWORD_THIS};
 use crate::error::{LexError, ParseError, ParseErrorType};
 use crate::module::{Module, ModuleRef};
 use crate::optimize::{optimize_into_ast, OptimizationLevel};
@@ -35,6 +35,12 @@ use crate::stdlib::{
     vec::Vec,
 };
 
+#[cfg(not(feature = "no_std"))]
+use crate::stdlib::collections::hash_map::DefaultHasher;
+
+#[cfg(feature = "no_std")]
+use ahash::AHasher;
+
 /// The system integer type.
 ///
 /// If the `only_i32` feature is enabled, this will be `i32` instead.
@@ -598,21 +604,35 @@ impl Hash for CustomExpr {
     }
 }
 
+#[cfg(not(feature = "no_float"))]
+#[derive(Debug, PartialEq, PartialOrd, Clone)]
+pub struct FloatWrapper(pub FLOAT, pub Position);
+
+#[cfg(not(feature = "no_float"))]
+impl Hash for FloatWrapper {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        state.write(&self.0.to_le_bytes());
+        self.1.hash(state);
+    }
+}
+
 /// An expression.
 ///
 /// Each variant is at most one pointer in size (for speed),
 /// with everything being allocated together in one single tuple.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash)]
 pub enum Expr {
     /// Integer constant.
     IntegerConstant(Box<(INT, Position)>),
     /// Floating-point constant.
     #[cfg(not(feature = "no_float"))]
-    FloatConstant(Box<(FLOAT, Position)>),
+    FloatConstant(Box<FloatWrapper>),
     /// Character constant.
     CharConstant(Box<(char, Position)>),
     /// String constant.
     StringConstant(Box<(ImmutableString, Position)>),
+    /// FnPtr constant.
+    FnPointer(Box<(ImmutableString, Position)>),
     /// Variable access - ((variable name, position), optional modules, hash, optional index)
     Variable(
         Box<(
@@ -623,7 +643,7 @@ pub enum Expr {
         )>,
     ),
     /// Property access.
-    Property(Box<((String, String, String), Position)>),
+    Property(Box<((ImmutableString, String, String), Position)>),
     /// { stmt }
     Stmt(Box<(Stmt, Position)>),
     /// Wrapped expression - should not be optimized away.
@@ -637,7 +657,7 @@ pub enum Expr {
             Option<Box<ModuleRef>>,
             u64,
             StaticVec<Expr>,
-            Option<Dynamic>,
+            Option<bool>,
         )>,
     ),
     /// expr op= expr
@@ -673,18 +693,6 @@ impl Default for Expr {
     }
 }
 
-impl Hash for Expr {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        match self {
-            Self::FloatConstant(x) => {
-                state.write(&x.0.to_le_bytes());
-                x.1.hash(state);
-            }
-            _ => self.hash(state),
-        }
-    }
-}
-
 impl Expr {
     /// Get the `Dynamic` value of a constant expression.
     ///
@@ -758,6 +766,7 @@ impl Expr {
             Self::IntegerConstant(x) => x.1,
             Self::CharConstant(x) => x.1,
             Self::StringConstant(x) => x.1,
+            Self::FnPointer(x) => x.1,
             Self::Array(x) => x.1,
             Self::Map(x) => x.1,
             Self::Property(x) => x.1,
@@ -791,6 +800,7 @@ impl Expr {
             Self::IntegerConstant(x) => x.1 = new_pos,
             Self::CharConstant(x) => x.1 = new_pos,
             Self::StringConstant(x) => x.1 = new_pos,
+            Self::FnPointer(x) => x.1 = new_pos,
             Self::Array(x) => x.1 = new_pos,
             Self::Map(x) => x.1 = new_pos,
             Self::Variable(x) => (x.0).1 = new_pos,
@@ -847,6 +857,7 @@ impl Expr {
             Self::IntegerConstant(_)
             | Self::CharConstant(_)
             | Self::StringConstant(_)
+            | Self::FnPointer(_)
             | Self::True(_)
             | Self::False(_)
             | Self::Unit(_) => true,
@@ -878,6 +889,7 @@ impl Expr {
 
             Self::IntegerConstant(_)
             | Self::CharConstant(_)
+            | Self::FnPointer(_)
             | Self::In(_)
             | Self::And(_)
             | Self::Or(_)
@@ -925,7 +937,7 @@ impl Expr {
                 let (name, pos) = x.0;
                 let getter = make_getter(&name);
                 let setter = make_setter(&name);
-                Self::Property(Box::new(((name.clone(), getter, setter), pos)))
+                Self::Property(Box::new(((name.into(), getter, setter), pos)))
             }
             _ => self,
         }
@@ -1476,7 +1488,7 @@ fn parse_primary(
     let mut root_expr = match token {
         Token::IntegerConstant(x) => Expr::IntegerConstant(Box::new((x, settings.pos))),
         #[cfg(not(feature = "no_float"))]
-        Token::FloatConstant(x) => Expr::FloatConstant(Box::new((x, settings.pos))),
+        Token::FloatConstant(x) => Expr::FloatConstant(Box::new(FloatWrapper(x, settings.pos))),
         Token::CharConstant(c) => Expr::CharConstant(Box::new((c, settings.pos))),
         Token::StringConstant(s) => Expr::StringConstant(Box::new((s.into(), settings.pos))),
         Token::Identifier(s) => {
@@ -1616,7 +1628,10 @@ fn parse_unary(
                         .map(|i| Expr::IntegerConstant(Box::new((i, pos))))
                         .or_else(|| {
                             #[cfg(not(feature = "no_float"))]
-                            return Some(Expr::FloatConstant(Box::new((-(x.0 as FLOAT), pos))));
+                            return Some(Expr::FloatConstant(Box::new(FloatWrapper(
+                                -(x.0 as FLOAT),
+                                pos,
+                            ))));
                             #[cfg(feature = "no_float")]
                             return None;
                         })
@@ -1625,7 +1640,9 @@ fn parse_unary(
 
                 // Negative float
                 #[cfg(not(feature = "no_float"))]
-                Expr::FloatConstant(x) => Ok(Expr::FloatConstant(Box::new((-x.0, x.1)))),
+                Expr::FloatConstant(x) => {
+                    Ok(Expr::FloatConstant(Box::new(FloatWrapper(-x.0, x.1))))
+                }
 
                 // Call negative function
                 expr => {
@@ -1664,9 +1681,38 @@ fn parse_unary(
                 None,
                 hash,
                 args,
-                Some(false.into()), // NOT operator, when operating on invalid operand, defaults to false
+                Some(false), // NOT operator, when operating on invalid operand, defaults to false
             ))))
         }
+        // | ...
+        #[cfg(not(feature = "no_function"))]
+        Token::Pipe | Token::Or => {
+            let mut state = ParseState::new(
+                state.engine,
+                state.max_function_expr_depth,
+                state.max_function_expr_depth,
+            );
+
+            let settings = ParseSettings {
+                allow_if_expr: true,
+                allow_stmt_expr: true,
+                allow_anonymous_fn: true,
+                is_global: false,
+                is_function_scope: true,
+                is_breakable: false,
+                level: 0,
+                pos: *token_pos,
+            };
+
+            let (expr, func) = parse_anon_fn(input, &mut state, lib, settings)?;
+
+            // Qualifiers (none) + function name + number of arguments.
+            let hash = calc_fn_hash(empty(), &func.name, func.params.len(), empty());
+
+            lib.insert(hash, func);
+
+            Ok(expr)
+        }
         // <EOF>
         Token::EOF => Err(PERR::UnexpectedEOF.into_err(settings.pos)),
         // All other tokens
@@ -1788,7 +1834,7 @@ fn make_dot_expr(lhs: Expr, rhs: Expr, op_pos: Position) -> Result<Expr, ParseEr
 
             let getter = make_getter(&name);
             let setter = make_setter(&name);
-            let rhs = Expr::Property(Box::new(((name, getter, setter), pos)));
+            let rhs = Expr::Property(Box::new(((name.into(), getter, setter), pos)));
 
             Expr::Dot(Box::new((lhs, rhs, op_pos)))
         }
@@ -2018,7 +2064,7 @@ fn parse_binary_op(
         settings.pos = pos;
         settings.ensure_level_within_max_limit(state.max_expr_depth)?;
 
-        let cmp_def = Some(false.into());
+        let cmp_def = Some(false);
         let op = op_token.syntax();
         let hash = calc_fn_hash(empty(), &op, 2, empty());
         let op = (op, true, pos);
@@ -2041,7 +2087,7 @@ fn parse_binary_op(
             | Token::XOr => Expr::FnCall(Box::new((op, None, hash, args, None))),
 
             // '!=' defaults to true when passed invalid operands
-            Token::NotEqualsTo => Expr::FnCall(Box::new((op, None, hash, args, Some(true.into())))),
+            Token::NotEqualsTo => Expr::FnCall(Box::new((op, None, hash, args, Some(true)))),
 
             // Comparison operators default to false when passed invalid operands
             Token::EqualsTo
@@ -2762,32 +2808,28 @@ fn parse_fn(
     let mut params = Vec::new();
 
     if !match_token(input, Token::RightParen)? {
-        let end_err = format!("to close the parameters list of function '{}'", name);
         let sep_err = format!("to separate the parameters of function '{}'", name);
 
         loop {
-            match input.peek().unwrap() {
-                (Token::RightParen, _) => (),
-                _ => match input.next().unwrap() {
+            match input.next().unwrap() {
+                (Token::RightParen, _) => break,
                 (Token::Identifier(s), pos) => {
                     state.stack.push((s.clone(), ScopeEntryType::Normal));
                     params.push((s, pos))
                 }
                 (Token::LexError(err), pos) => return Err(err.into_err(pos)),
                 (_, pos) => {
-                        return Err(
-                            PERR::MissingToken(Token::RightParen.into(), end_err).into_err(pos)
+                    return Err(PERR::MissingToken(
+                        Token::RightParen.into(),
+                        format!("to close the parameters list of function '{}'", name),
                     )
+                    .into_err(pos))
                 }
-                },
             }
 
             match input.next().unwrap() {
                 (Token::RightParen, _) => break,
                 (Token::Comma, _) => (),
-                (Token::Identifier(_), pos) => {
-                    return Err(PERR::MissingToken(Token::Comma.into(), sep_err).into_err(pos))
-                }
                 (Token::LexError(err), pos) => return Err(err.into_err(pos)),
                 (_, pos) => {
                     return Err(PERR::MissingToken(Token::Comma.into(), sep_err).into_err(pos))
@@ -2831,6 +2873,101 @@ fn parse_fn(
     })
 }
 
+/// Parse an anonymous function definition.
+#[cfg(not(feature = "no_function"))]
+fn parse_anon_fn(
+    input: &mut TokenStream,
+    state: &mut ParseState,
+    lib: &mut FunctionsLib,
+    mut settings: ParseSettings,
+) -> Result<(Expr, ScriptFnDef), ParseError> {
+    settings.ensure_level_within_max_limit(state.max_expr_depth)?;
+
+    let mut params = Vec::new();
+
+    if input.next().unwrap().0 != Token::Or {
+        if !match_token(input, Token::Pipe)? {
+            loop {
+                match input.next().unwrap() {
+                    (Token::Pipe, _) => break,
+                    (Token::Identifier(s), pos) => {
+                        state.stack.push((s.clone(), ScopeEntryType::Normal));
+                        params.push((s, pos))
+                    }
+                    (Token::LexError(err), pos) => return Err(err.into_err(pos)),
+                    (_, pos) => {
+                        return Err(PERR::MissingToken(
+                            Token::Pipe.into(),
+                            "to close the parameters list of anonymous function".into(),
+                        )
+                        .into_err(pos))
+                    }
+                }
+
+                match input.next().unwrap() {
+                    (Token::Pipe, _) => break,
+                    (Token::Comma, _) => (),
+                    (Token::LexError(err), pos) => return Err(err.into_err(pos)),
+                    (_, pos) => {
+                        return Err(PERR::MissingToken(
+                            Token::Comma.into(),
+                            "to separate the parameters of anonymous function".into(),
+                        )
+                        .into_err(pos))
+                    }
+                }
+            }
+        }
+    }
+
+    // Check for duplicating parameters
+    params
+        .iter()
+        .enumerate()
+        .try_for_each(|(i, (p1, _))| {
+            params
+                .iter()
+                .skip(i + 1)
+                .find(|(p2, _)| p2 == p1)
+                .map_or_else(|| Ok(()), |(p2, pos)| Err((p2, *pos)))
+        })
+        .map_err(|(p, pos)| PERR::FnDuplicatedParam("".to_string(), p.to_string()).into_err(pos))?;
+
+    // Parse function body
+    settings.is_breakable = false;
+    let pos = input.peek().unwrap().1;
+    let body = parse_stmt(input, state, lib, settings.level_up())
+        .map(|stmt| stmt.unwrap_or_else(|| Stmt::Noop(pos)))?;
+
+    let params: StaticVec<_> = params.into_iter().map(|(p, _)| p).collect();
+
+    // Calculate hash
+    #[cfg(feature = "no_std")]
+    let mut s: AHasher = Default::default();
+    #[cfg(not(feature = "no_std"))]
+    let mut s = DefaultHasher::new();
+
+    s.write_usize(params.len());
+    params.iter().for_each(|a| a.hash(&mut s));
+    body.hash(&mut s);
+    let hash = s.finish();
+
+    // Create unique function name
+    let fn_name = format!("{}{}", FN_ANONYMOUS, hash);
+
+    let script = ScriptFnDef {
+        name: fn_name.clone(),
+        access: FnAccess::Public,
+        params,
+        body,
+        pos: settings.pos,
+    };
+
+    let expr = Expr::FnPointer(Box::new((fn_name.into(), settings.pos)));
+
+    Ok((expr, script))
+}
+
 impl Engine {
     pub(crate) fn parse_global_expr(
         &self,
@@ -2951,7 +3088,7 @@ impl Engine {
 pub fn map_dynamic_to_expr(value: Dynamic, pos: Position) -> Option<Expr> {
     match value.0 {
         #[cfg(not(feature = "no_float"))]
-        Union::Float(value) => Some(Expr::FloatConstant(Box::new((value, pos)))),
+        Union::Float(value) => Some(Expr::FloatConstant(Box::new(FloatWrapper(value, pos)))),
 
         Union::Unit(_) => Some(Expr::Unit(pos)),
         Union::Int(value) => Some(Expr::IntegerConstant(Box::new((value, pos)))),

src/syntax.rs

@@ -22,26 +22,13 @@ use crate::stdlib::{
 #[cfg(not(feature = "sync"))]
 pub type FnCustomSyntaxEval = dyn Fn(
     &Engine,
+    &mut EvalContext,
     &mut Scope,
-    &mut Imports,
-    &mut State,
-    &Module,
-    &mut Option<&mut Dynamic>,
     &[Expression],
-    usize,
 ) -> Result<Dynamic, Box<EvalAltResult>>;
 /// A general function trail object.
 #[cfg(feature = "sync")]
-pub type FnCustomSyntaxEval = dyn Fn(
-        &Engine,
-        &mut Scope,
-        &mut Imports,
-        &mut State,
-        &Module,
-        &mut Option<&mut Dynamic>,
-        &[Expression],
-        usize,
-    ) -> Result<Dynamic, Box<EvalAltResult>>
+pub type FnCustomSyntaxEval = dyn Fn(&Engine, &mut EvalContext, &mut Scope, &[Expression]) -> Result<Dynamic, Box<EvalAltResult>>
     + Send
     + Sync;
 
@@ -58,6 +45,14 @@ impl fmt::Debug for CustomSyntax {
     }
 }
 
+pub struct EvalContext<'a, 'b: 'a, 's, 'm, 't, 'd: 't> {
+    pub(crate) mods: &'a mut Imports<'b>,
+    pub(crate) state: &'s mut State,
+    pub(crate) lib: &'m Module,
+    pub(crate) this_ptr: &'t mut Option<&'d mut Dynamic>,
+    pub(crate) level: usize,
+}
+
 impl Engine {
     pub fn register_custom_syntax<S: AsRef<str> + ToString>(
         &mut self,
@@ -65,13 +60,9 @@ impl Engine {
         scope_delta: isize,
         func: impl Fn(
                 &Engine,
+                &mut EvalContext,
                 &mut Scope,
-                &mut Imports,
-                &mut State,
-                &Module,
-                &mut Option<&mut Dynamic>,
                 &[Expression],
-                usize,
             ) -> Result<Dynamic, Box<EvalAltResult>>
             + SendSync
             + 'static,

src/unsafe.rs

@@ -12,6 +12,7 @@ use crate::stdlib::{
 };
 
 /// Cast a type into another type.
+#[inline(always)]
 pub fn unsafe_try_cast<A: Any, B: Any>(a: A) -> Option<B> {
     if TypeId::of::<B>() == a.type_id() {
         // SAFETY: Just checked we have the right type. We explicitly forget the
@@ -28,6 +29,7 @@ pub fn unsafe_try_cast<A: Any, B: Any>(a: A) -> Option<B> {
 }
 
 /// Cast a Boxed type into another type.
+#[inline(always)]
 pub fn unsafe_cast_box<X: Variant, T: Variant>(item: Box<X>) -> Result<Box<T>, Box<X>> {
     // Only allow casting to the exact same type
     if TypeId::of::<X>() == TypeId::of::<T>() {
@@ -51,6 +53,7 @@ pub fn unsafe_cast_box<X: Variant, T: Variant>(item: Box<X>) -> Result<Box<T>, B
 ///
 /// Force-casting a local variable's lifetime to the current `Scope`'s larger lifetime saves
 /// on allocations and string cloning, thus avoids us having to maintain a chain of `Scope`'s.
+#[inline]
 pub fn unsafe_cast_var_name_to_lifetime<'s>(name: &str, state: &State) -> Cow<'s, str> {
     // If not at global level, we can force-cast
     if state.scope_level > 0 {

src/utils.rs

@@ -36,11 +36,9 @@ use ahash::AHasher;
 pub struct StraightHasher(u64);
 
 impl Hasher for StraightHasher {
-    #[inline(always)]
     fn finish(&self) -> u64 {
         self.0
     }
-    #[inline]
     fn write(&mut self, bytes: &[u8]) {
         let mut key = [0_u8; 8];
         key.copy_from_slice(&bytes[..8]); // Panics if fewer than 8 bytes
@@ -50,7 +48,6 @@ impl Hasher for StraightHasher {
 
 impl StraightHasher {
     /// Create a `StraightHasher`.
-    #[inline(always)]
     pub fn new() -> Self {
         Self(0)
     }
@@ -63,7 +60,6 @@ pub struct StraightHasherBuilder;
 impl BuildHasher for StraightHasherBuilder {
     type Hasher = StraightHasher;
 
-    #[inline(always)]
     fn build_hasher(&self) -> Self::Hasher {
         StraightHasher::new()
     }
@@ -150,7 +146,6 @@ pub struct StaticVec<T> {
 const MAX_STATIC_VEC: usize = 4;
 
 impl<T> Drop for StaticVec<T> {
-    #[inline(always)]
     fn drop(&mut self) {
         self.clear();
     }
@@ -233,7 +228,6 @@ impl<T: 'static> IntoIterator for StaticVec<T> {
 
 impl<T> StaticVec<T> {
     /// Create a new `StaticVec`.
-    #[inline(always)]
     pub fn new() -> Self {
         Default::default()
     }
@@ -249,7 +243,6 @@ impl<T> StaticVec<T> {
         self.len = 0;
     }
     /// Extract a `MaybeUninit` into a concrete initialized type.
-    #[inline(always)]
     fn extract(value: MaybeUninit<T>) -> T {
         unsafe { value.assume_init() }
     }
@@ -311,7 +304,6 @@ impl<T> StaticVec<T> {
         );
     }
     /// Is data stored in fixed-size storage?
-    #[inline(always)]
     fn is_fixed_storage(&self) -> bool {
         self.len <= MAX_STATIC_VEC
     }
@@ -418,12 +410,10 @@ impl<T> StaticVec<T> {
         }
     }
     /// Get the number of items in this `StaticVec`.
-    #[inline(always)]
     pub fn len(&self) -> usize {
         self.len
     }
     /// Is this `StaticVec` empty?
-    #[inline(always)]
     pub fn is_empty(&self) -> bool {
         self.len == 0
     }
@@ -664,48 +654,41 @@ pub struct ImmutableString(Shared<String>);
 impl Deref for ImmutableString {
     type Target = String;
 
-    #[inline(always)]
     fn deref(&self) -> &Self::Target {
         &self.0
     }
 }
 
 impl AsRef<String> for ImmutableString {
-    #[inline(always)]
     fn as_ref(&self) -> &String {
         &self.0
     }
 }
 
 impl Borrow<str> for ImmutableString {
-    #[inline(always)]
     fn borrow(&self) -> &str {
         self.0.as_str()
     }
 }
 
 impl From<&str> for ImmutableString {
-    #[inline(always)]
     fn from(value: &str) -> Self {
         Self(value.to_string().into())
     }
 }
 impl From<String> for ImmutableString {
-    #[inline(always)]
     fn from(value: String) -> Self {
         Self(value.into())
     }
 }
 
 impl From<Box<String>> for ImmutableString {
-    #[inline(always)]
     fn from(value: Box<String>) -> Self {
         Self(value.into())
     }
 }
 
 impl From<ImmutableString> for String {
-    #[inline(always)]
     fn from(value: ImmutableString) -> Self {
         value.into_owned()
     }
@@ -714,49 +697,42 @@ impl From<ImmutableString> for String {
 impl FromStr for ImmutableString {
     type Err = ();
 
-    #[inline(always)]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Ok(Self(s.to_string().into()))
     }
 }
 
 impl FromIterator<char> for ImmutableString {
-    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = char>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<&'a char> for ImmutableString {
-    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = &'a char>>(iter: T) -> Self {
         Self(iter.into_iter().cloned().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<&'a str> for ImmutableString {
-    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = &'a str>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl<'a> FromIterator<String> for ImmutableString {
-    #[inline(always)]
     fn from_iter<T: IntoIterator<Item = String>>(iter: T) -> Self {
         Self(iter.into_iter().collect::<String>().into())
     }
 }
 
 impl fmt::Display for ImmutableString {
-    #[inline(always)]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(self.0.as_str(), f)
     }
 }
 
 impl fmt::Debug for ImmutableString {
-    #[inline(always)]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(self.0.as_str(), f)
     }
@@ -891,7 +867,6 @@ impl Add<char> for &ImmutableString {
 }
 
 impl AddAssign<char> for ImmutableString {
-    #[inline(always)]
     fn add_assign(&mut self, rhs: char) {
         self.make_mut().push(rhs);
     }
@@ -906,7 +881,6 @@ impl ImmutableString {
     }
     /// Make sure that the `ImmutableString` is unique (i.e. no other outstanding references).
     /// Then return a mutable reference to the `String`.
-    #[inline(always)]
     pub fn make_mut(&mut self) -> &mut String {
         shared_make_mut(&mut self.0)
     }

tests/call_fn.rs

@@ -1,7 +1,6 @@
 #![cfg(not(feature = "no_function"))]
 use rhai::{
-    Dynamic, Engine, EvalAltResult, FnPtr, Func, ImmutableString, Module, ParseError,
-    ParseErrorType, Scope, INT,
+    Dynamic, Engine, EvalAltResult, FnPtr, Func, Module, ParseError, ParseErrorType, Scope, INT,
 };
 
 #[test]

tests/syntax.rs

@@ -1,8 +1,5 @@
 #![cfg(feature = "internals")]
-use rhai::{
-    Dynamic, Engine, EvalAltResult, EvalState, Expression, Imports, LexError, Module, ParseError,
-    ParseErrorType, Scope, INT,
-};
+use rhai::{Engine, EvalAltResult, EvalContext, Expression, LexError, ParseErrorType, Scope, INT};
 
 #[test]
 fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
@@ -28,13 +25,9 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
             ],
             1,
             |engine: &Engine,
+             context: &mut EvalContext,
              scope: &mut Scope,
-             mods: &mut Imports,
-             state: &mut EvalState,
-             lib: &Module,
-             this_ptr: &mut Option<&mut Dynamic>,
-             inputs: &[Expression],
-             level: usize| {
+             inputs: &[Expression]| {
                 let var_name = inputs[0].get_variable_name().unwrap().to_string();
                 let stmt = inputs.get(1).unwrap();
                 let expr = inputs.get(2).unwrap();
@@ -42,10 +35,10 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
                 scope.push(var_name, 0 as INT);
 
                 loop {
-                    engine.eval_expression_tree(scope, mods, state, lib, this_ptr, stmt, level)?;
+                    engine.eval_expression_tree(context, scope, stmt)?;
 
                     if !engine
-                        .eval_expression_tree(scope, mods, state, lib, this_ptr, expr, level)?
+                        .eval_expression_tree(context, scope, expr)?
                         .as_bool()
                         .map_err(|_| {
                             EvalAltResult::ErrorBooleanArgMismatch(
@@ -78,7 +71,7 @@ fn test_custom_syntax() -> Result<(), Box<EvalAltResult>> {
 
     // The first symbol must be an identifier
     assert!(matches!(
-        *engine.register_custom_syntax(&["!"], 0, |_, _, _, _, _, _, _, _| Ok(().into())).expect_err("should error"),
+        *engine.register_custom_syntax(&["!"], 0, |_, _, _, _| Ok(().into())).expect_err("should error"),
         LexError::ImproperSymbol(s) if s == "!"
     ));