Bump version to 0.12.0.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rhai"
-version = "0.11.0"
+version = "0.12.0"
 edition = "2018"
 authors = ["Jonathan Turner", "Lukáš Hozda", "Stephen Chung"]
 description = "Embedded scripting for Rust"

README.md

@@ -27,7 +27,7 @@ Rhai's current features set:
   to do checked arithmetic operations); for [`no_std`] builds, a number of additional dependencies are
   pulled in to provide for functionalities that used to be in `std`.
 
-**Note:** Currently, the version is 0.11.0, so the language and API's may change before they stabilize.
+**Note:** Currently, the version is 0.12.0, so the language and API's may change before they stabilize.
 
 Installation
 ------------
@@ -36,7 +36,7 @@ Install the Rhai crate by adding this line to `dependencies`:
 
 ```toml
 [dependencies]
-rhai = "0.11.0"
+rhai = "0.12.0"
 ```
 
 Use the latest released crate version on [`crates.io`](https::/crates.io/crates/rhai/):
@@ -207,7 +207,7 @@ let ast = engine.compile("40 + 2")?;
 for _ in 0..42 {
     let result: i64 = engine.eval_ast(&ast)?;
 
-println!("Answer #{}: {}", i, result);          // prints 42
+    println!("Answer #{}: {}", i, result);      // prints 42
 }
 ```
 
@@ -263,9 +263,10 @@ let result: i64 = engine.call_fn(&mut scope, &ast, "hello", () )?
 
 [`Func`]: #creating-rust-anonymous-functions-from-rhai-script
 
-It is possible to further encapsulate a script in Rust such that it essentially becomes a normal Rust function.
+It is possible to further encapsulate a script in Rust such that it becomes a normal Rust function.
-This is accomplished via the `Func` trait which contains `create_from_script` (as well as its associate
+Such an _anonymous function_ is basically a boxed closure, very useful as call-back functions.
-method `create_from_ast`):
+Creating them is accomplished via the `Func` trait which contains `create_from_script`
+(as well as its companion method `create_from_ast`):
 
 ```rust
 use rhai::{Engine, Func};                       // use 'Func' for 'create_from_script'
@@ -288,6 +289,15 @@ let func = Func::<(i64, String), bool>::create_from_script(
 )?;
 
 func(123, "hello".to_string())? == false;       // call the anonymous function
+
+schedule_callback(func);                        // pass it as a callback to another function
+
+// Although there is nothing you can't do by manually writing out the closure yourself...
+let engine = Engine::new();
+let ast = engine.compile(script)?;
+schedule_callback(Box::new(move |x: i64, y: String| -> Result<bool, EvalAltResult> {
+    engine.call_fn(&mut Scope::new(), &ast, "calc", (x, y))
+}));
 ```
 
 Raw `Engine`

src/engine.rs

@@ -50,7 +50,7 @@ type IteratorFn = dyn Fn(&Dynamic) -> Box<dyn Iterator<Item = Dynamic>> + Send +
 type IteratorFn = dyn Fn(&Dynamic) -> Box<dyn Iterator<Item = Dynamic>>;
 
 #[cfg(debug_assertions)]
-pub const MAX_CALL_STACK_DEPTH: usize = 42;
+pub const MAX_CALL_STACK_DEPTH: usize = 32;
 
 #[cfg(not(debug_assertions))]
 pub const MAX_CALL_STACK_DEPTH: usize = 256;
@@ -277,7 +277,7 @@ pub struct Engine<'e> {
 
     /// Maximum levels of call-stack to prevent infinite recursion.
     ///
-    /// Defaults to 42 for debug builds and 256 for non-debug builds.
+    /// Defaults to 32 for debug builds and 256 for non-debug builds.
     pub(crate) max_call_stack_depth: usize,
 }
 
@@ -372,11 +372,6 @@ impl Engine<'_> {
 
     /// Create a new `Engine`
     pub fn new() -> Self {
-        // fn abc<F: Fn() + Send + Sync>(f: F) {
-        //     f();
-        // }
-        // abc(|| ());
-
         Default::default()
     }
 
@@ -420,32 +415,6 @@ impl Engine<'_> {
         self.max_call_stack_depth = levels
     }
 
-    /// Call a registered function
-    #[cfg(not(feature = "no_optimize"))]
-    pub(crate) fn call_ext_fn_raw(
-        &self,
-        fn_name: &str,
-        args: &mut FnCallArgs,
-        pos: Position,
-    ) -> Result<Option<Dynamic>, EvalAltResult> {
-        let spec = FnSpec {
-            name: fn_name.into(),
-            args: args.iter().map(|a| Any::type_id(*a)).collect(),
-        };
-
-        // Search built-in's and external functions
-        if let Some(functions) = &self.functions {
-            if let Some(func) = functions.get(&spec) {
-                // Run external function
-                Ok(Some(func(args, pos)?))
-            } else {
-                Ok(None)
-            }
-        } else {
-            Ok(None)
-        }
-    }
-
     /// Universal method for calling functions either registered with the `Engine` or written in Rhai
     pub(crate) fn call_fn_raw(
         &self,

src/fn_register.rs

@@ -132,9 +132,9 @@ macro_rules! def_register {
         def_register!(imp);
     };
     (imp $($par:ident => $mark:ty => $param:ty => $clone:expr),*) => {
-    //     ^ function parameter generic type name
+    //     ^ function parameter generic type name (A, B, C etc.)
     //                   ^ function parameter marker type (T, Ref<T> or Mut<T>)
-    //                               ^ function parameter actual type
+    //                               ^ function parameter actual type (T, &T or &mut T)
     //                                            ^ dereferencing function
         impl<
             $($par: Any + Clone,)*
@@ -171,6 +171,7 @@ macro_rules! def_register {
                     let r = f($(($clone)($par)),*);
                     Ok(Box::new(r) as Dynamic)
                 };
+
                 self.register_fn_raw(name, vec![$(TypeId::of::<$par>()),*], Box::new(func));
             }
         }
@@ -255,9 +256,10 @@ macro_rules! def_register {
         def_register!(imp $p0 => $p0      => $p0      => Clone::clone   $(, $p => $p => $p => Clone::clone)*);
         def_register!(imp $p0 => Mut<$p0> => &mut $p0 => identity       $(, $p => $p => $p => Clone::clone)*);
         // handle the first parameter                    ^ first parameter passed through
-        //                                                    others passed by value (cloned) ^
+        //                                                                                    ^ others passed by value (cloned)
 
-        // No support for functions where the first argument is a reference
+        // Currently does not support first argument which is a reference, as there will be
+        // conflicting implementations since &T: Any and T: Any cannot be distinguished
         //def_register!(imp $p0 => Ref<$p0> => &$p0     => identity       $(, $p => $p => $p => Clone::clone)*);
 
         def_register!($($p),*);

src/lib.rs

@@ -38,6 +38,7 @@
 //!
 //! #   #[cfg(not(feature = "no_std"))]
 //!     assert_eq!(
+//!         // Evaluate the script, expects a 'bool' return
 //!         engine.eval_file::<bool>("my_script.rhai".into())?,
 //!         true
 //!     );

src/optimize.rs

@@ -2,14 +2,16 @@
 
 use crate::any::{Any, Dynamic};
 use crate::engine::{
-    Engine, FunctionsLib, KEYWORD_DEBUG, KEYWORD_DUMP_AST, KEYWORD_EVAL, KEYWORD_PRINT,
+    Engine, FnAny, FnCallArgs, FnSpec, FunctionsLib, KEYWORD_DEBUG, KEYWORD_DUMP_AST, KEYWORD_EVAL,
-    KEYWORD_TYPE_OF,
+    KEYWORD_PRINT, KEYWORD_TYPE_OF,
 };
-use crate::parser::{map_dynamic_to_expr, Expr, FnDef, ReturnType, Stmt, AST};
+use crate::parser::{map_dynamic_to_expr, Expr, FnDef, Position, ReturnType, Stmt, AST};
+use crate::result::EvalAltResult;
 use crate::scope::{Entry as ScopeEntry, EntryType as ScopeEntryType, Scope};
 
 use crate::stdlib::{
     boxed::Box,
+    collections::HashMap,
     rc::Rc,
     string::{String, ToString},
     sync::Arc,
@@ -96,6 +98,25 @@ impl<'a> State<'a> {
     }
 }
 
+/// Call a registered function
+fn call_fn(
+    functions: Option<&HashMap<FnSpec, Box<FnAny>>>,
+    fn_name: &str,
+    args: &mut FnCallArgs,
+    pos: Position,
+) -> Result<Option<Dynamic>, EvalAltResult> {
+    let spec = FnSpec {
+        name: fn_name.into(),
+        args: args.iter().map(|a| Any::type_id(*a)).collect(),
+    };
+
+    // Search built-in's and external functions
+    functions
+        .and_then(|f| f.get(&spec))
+        .map(|func| func(args, pos))
+        .transpose()
+}
+
 /// Optimize a statement.
 fn optimize_stmt<'a>(stmt: Stmt, state: &mut State<'a>, preserve_result: bool) -> Stmt {
     match stmt {
@@ -528,21 +549,25 @@ fn optimize_expr<'a>(expr: Expr, state: &mut State<'a>) -> Expr {
                 ""
             };
 
-            state.engine.call_ext_fn_raw(&id, &mut call_args, pos).ok().map(|result|
+            call_fn(state.engine.functions.as_ref(), &id, &mut call_args, pos).ok()
-                result.or_else(|| {
+                .and_then(|result|
-                    if !arg_for_type_of.is_empty() {
+                    result.or_else(|| {
-                        // Handle `type_of()`
+                        if !arg_for_type_of.is_empty() {
-                        Some(arg_for_type_of.to_string().into_dynamic())
+                            // Handle `type_of()`
-                    } else {
+                            Some(arg_for_type_of.to_string().into_dynamic())
-                        // Otherwise use the default value, if any
+                        } else {
-                        def_value.clone()
+                            // Otherwise use the default value, if any
-                    }
+                            def_value.clone()
-                }).and_then(|result| map_dynamic_to_expr(result, pos))
+                        }
+                    }).and_then(|result| map_dynamic_to_expr(result, pos))
                     .map(|expr| {
                         state.set_dirty();
                         expr
                     })
-            ).flatten().unwrap_or_else(|| Expr::FunctionCall(id, args, def_value, pos))
+                ).unwrap_or_else(||
+                    // Optimize function call arguments
+                    Expr::FunctionCall(id, args.into_iter().map(|a| optimize_expr(a, state)).collect(), def_value, pos)
+                )
         }
 
         // id(args ..) -> optimize function call arguments

tests/call_fn.rs

@@ -62,9 +62,6 @@ fn test_call_fn() -> Result<(), EvalAltResult> {
 
 #[test]
 fn test_anonymous_fn() -> Result<(), EvalAltResult> {
-    let calc_func: Box<dyn Fn(INT, INT, INT) -> Result<INT, EvalAltResult>> =
-        Engine::new().create_from_script("fn calc() { 42 }", "calc")?;
-
     let calc_func = Func::<(INT, INT, INT), INT>::create_from_script(
         Engine::new(),
         "fn calc(x, y, z) { (x + y) * z }",

tests/stack.rs

@@ -9,10 +9,10 @@ fn test_stack_overflow() -> Result<(), EvalAltResult> {
         engine.eval::<i64>(
             r"
                 fn foo(n) { if n == 0 { 0 } else { n + foo(n-1) } }
-                foo(38)
+                foo(30)
     ",
         )?,
-        741
+        465
     );
 
     match engine.eval::<()>(