Add threading example.

examples/threading.rs

@@ -0,0 +1,51 @@
+use rhai::{Engine, RegisterFn, INT};
+
+fn main() {
+    // Channel: Script -> Master
+    let (tx_script, rx_master) = std::sync::mpsc::channel();
+    // Channel: Master -> Script
+    let (tx_master, rx_script) = std::sync::mpsc::channel();
+
+    // Spawn thread with Engine
+    std::thread::spawn(move || {
+        // Create Engine
+        let mut engine = Engine::new();
+
+        // Register API
+        // Notice that the API functions are blocking
+        engine
+            .register_fn("get", move || rx_script.recv().unwrap())
+            .register_fn("put", move |v: INT| tx_script.send(v).unwrap());
+
+        // Run script
+        engine
+            .consume(
+                r#"
+                    print("Starting script loop...");
+
+                    loop {
+                        let x = get();
+                        print("Script Read: " + x);
+                        x += 1;
+                        print("Script Write: " + x);
+                        put(x);
+                    }
+                "#,
+            )
+            .unwrap();
+    });
+
+    // This is the main processing thread
+
+    println!("Starting main loop...");
+
+    let mut value: INT = 0;
+
+    while value < 10 {
+        println!("Value: {}", value);
+        // Send value to script
+        tx_master.send(value).unwrap();
+        // Receive value from script
+        value = rx_master.recv().unwrap();
+    }
+}

src/fn_args.rs

@@ -19,7 +19,7 @@ macro_rules! impl_args {
     ($($p:ident),*) => {
         impl<$($p: Variant + Clone),*> FuncArgs for ($($p,)*)
         {
-            #[inline]
+            #[inline(always)]
             fn into_vec(self) -> StaticVec<Dynamic> {
                 let ($($p,)*) = self;
 

src/parser.rs

@@ -2870,7 +2870,9 @@ fn parse_fn(
 
 /// Creates a curried expression from a list of external variables
 #[cfg(not(feature = "no_function"))]
+#[cfg(not(feature = "no_closure"))]
 fn make_curry_from_externals(fn_expr: Expr, externals: StaticVec<Ident>, pos: Position) -> Expr {
+    // If there are no captured variables, no need to curry
     if externals.is_empty() {
         return fn_expr;
     }
@@ -2880,14 +2882,8 @@ fn make_curry_from_externals(fn_expr: Expr, externals: StaticVec<Ident>, pos: Po
 
     args.push(fn_expr);
 
-    #[cfg(not(feature = "no_closure"))]
     externals.iter().for_each(|x| {
-        args.push(Expr::Variable(Box::new((None, None, x.clone().into()))));
+        args.push(Expr::Variable(Box::new((None, None, x.clone()))));
-    });
-
-    #[cfg(feature = "no_closure")]
-    externals.into_iter().for_each(|x| {
-        args.push(Expr::Variable(Box::new((None, None, x.clone().into()))));
     });
 
     let curry_func = crate::engine::KEYWORD_FN_PTR_CURRY;
@@ -2904,21 +2900,12 @@ fn make_curry_from_externals(fn_expr: Expr, externals: StaticVec<Ident>, pos: Po
         pos,
     );
 
-    // If there are captured variables, convert the entire expression into a statement block,
+    // Convert the entire expression into a statement block, then insert the relevant
-    // then insert the relevant `Share` statements.
+    // [`Share`][Stmt::Share] statements.
-    #[cfg(not(feature = "no_closure"))]
-    {
-        // Statement block
     let mut statements: StaticVec<_> = Default::default();
-        // Insert `Share` statements
+    statements.extend(externals.into_iter().map(Stmt::Share));
-        statements.extend(externals.into_iter().map(|x| Stmt::Share(x)));
-        // Final expression
     statements.push(Stmt::Expr(expr));
     Expr::Stmt(Box::new(statements), pos)
-    }
-
-    #[cfg(feature = "no_closure")]
-    return expr;
 }
 
 /// Parse an anonymous function definition.
@@ -3029,11 +3016,8 @@ fn parse_anon_fn(
 
     let expr = Expr::FnPointer(fn_name, settings.pos);
 
-    let expr = if cfg!(not(feature = "no_closure")) {
+    #[cfg(not(feature = "no_closure"))]
-        make_curry_from_externals(expr, externals, settings.pos)
+    let expr = make_curry_from_externals(expr, externals, settings.pos);
-    } else {
-        expr
-    };
 
     Ok((expr, script))
 }

tests/native.rs

@@ -1,4 +1,4 @@
-use rhai::{Dynamic, Engine, EvalAltResult, NativeCallContext, RegisterFn, INT};
+use rhai::{Dynamic, Engine, EvalAltResult, NativeCallContext, INT};
 use std::any::TypeId;
 
 #[test]