Merge pull request #400 from schungx/master

Automatic global module.

CHANGELOG.md

@@ -4,12 +4,24 @@ Rhai Release Notes
 Version 0.20.1
 ==============
 
+This version enables functions to access constants declared at global level via the special `global` module.
+
 Breaking changes
 ----------------
 
 * `Dynamic::is_shared` and `Dynamic::is_locked` are removed under the `no_closure` feature. They used to always return `false`.
 * `Engine::call_fn` now evaluates the `AST` before calling the function.
 
+Enhancements
+------------
+
+* The crate [`no-std-compat`](https://crates.io/crates/no_std_compat) is used to compile for `no-std`. This removes the need to use a special `crate::stdlib` namespace for `std` imports.
+
+New features
+------------
+
+* A module called `global` is automatically created to hold global-level constants, which can then be accessed from functions.
+
 
 Version 0.20.0
 ==============

scripts/function_decl3.rhai

@@ -1,9 +1,11 @@
 // This script defines a function with many parameters and calls it
 
+const KEY = 38;
+
 fn f(a, b, c, d, e, f) {
-    a - b * c - d * e - f
+    a - b * c - d * e - f + global::KEY
 }
 
-print("f() call should be 4:");
+print("f() call should be 42:");
 
 print(f(100, 5, 2, 9, 6, 32));

scripts/mat_mul.rhai

@@ -12,7 +12,7 @@ fn new_mat(x, y) {
 
 fn mat_gen(n) {
     let m = new_mat(n, n);
-    let tmp = 1.0 / n / n;
+    const tmp = 1.0 / n / n;
 
     for i in range(0, n) {
         for j in range(0, n) {
@@ -24,43 +24,36 @@ fn mat_gen(n) {
 }
 
 fn mat_mul(a, b) {
-    let m = a.len;
-    let n = a[0].len;
-    let p = b[0].len;
-
-    let b2 = new_mat(n, p);
+    let b2 = new_mat(a[0].len, b[0].len);
 	
-    for i in range(0, n) {
-        for j in range(0, p) {
+    for i in range(0, a[0].len) {
+        for j in range(0, b[0].len) {
             b2[j][i] = b[i][j];
         }
     }
 
-    let c = new_mat(m, p);
+    let c = new_mat(a.len, b[0].len);
 
 	for i in range(0, c.len) {
-		let ci = c[i];
-		for j in range(0, ci.len) {
-			let b2j = b2[j];
-			ci[j] = 0.0;
+		for j in range(0, c[i].len) {
+			c[i][j] = 0.0;
 			
 			for z in range(0, a[i].len) {
 				let x = a[i][z];
-				let y = b2j[z];
-				ci[j] += x * y;
+				let y = b2[j][z];
+				c[i][j] += x * y;
 			}
         }
-		c[i] = ci;
     }
 
     c
 }
 
-let now = timestamp();
+const now = timestamp();
 
-let a = mat_gen(SIZE);
-let b = mat_gen(SIZE);
-let c = mat_mul(a, b);
+const a = mat_gen(SIZE);
+const b = mat_gen(SIZE);
+const c = mat_mul(a, b);
 
 /*
 for i in range(0, SIZE) {

src/engine.rs

@@ -70,6 +70,12 @@ impl Imports {
     pub fn get(&self, index: usize) -> Option<Shared<Module>> {
         self.1.get(index).cloned()
     }
+    /// Get the imported [modules][Module] at a particular index.
+    #[allow(dead_code)]
+    #[inline(always)]
+    pub(crate) fn get_mut(&mut self, index: usize) -> Option<&mut Shared<Module>> {
+        self.1.get_mut(index)
+    }
     /// Get the index of an imported [modules][Module] by name.
     #[inline(always)]
     pub fn find(&self, name: &str) -> Option<usize> {
@@ -199,6 +205,8 @@ pub const KEYWORD_IS_DEF_VAR: &str = "is_def_var";
 #[cfg(not(feature = "no_function"))]
 pub const KEYWORD_IS_DEF_FN: &str = "is_def_fn";
 pub const KEYWORD_THIS: &str = "this";
+#[cfg(not(feature = "no_function"))]
+pub const KEYWORD_GLOBAL: &str = "global";
 #[cfg(not(feature = "no_object"))]
 pub const FN_GET: &str = "get$";
 #[cfg(not(feature = "no_object"))]
@@ -896,6 +904,7 @@ impl Engine {
             disable_doc_comments: false,
         };
 
+        engine.global_namespace.set_internal(true);
         engine.register_global_module(StandardPackage::new().as_shared_module());
 
         engine
@@ -906,7 +915,7 @@ impl Engine {
     /// Use [`register_global_module`][Engine::register_global_module] to add packages of functions.
     #[inline(always)]
     pub fn new_raw() -> Self {
-        Self {
+        let mut engine = Self {
             global_namespace: Default::default(),
             global_modules: Default::default(),
             global_sub_modules: Default::default(),
@@ -952,7 +961,11 @@ impl Engine {
             #[cfg(not(feature = "no_function"))]
             #[cfg(feature = "metadata")]
             disable_doc_comments: false,
-        }
+        };
+
+        engine.global_namespace.set_internal(true);
+
+        engine
     }
 
     /// Search for a module within an imports stack.
@@ -2504,6 +2517,31 @@ impl Engine {
                     .flatten();
 
                 let (var_name, _alias): (Cow<'_, str>, _) = if state.is_global() {
+                    #[cfg(not(feature = "no_function"))]
+                    if entry_type == AccessMode::ReadOnly && lib.iter().any(|&m| !m.is_empty()) {
+                        let global = if let Some(index) = mods.find(KEYWORD_GLOBAL) {
+                            let global = mods.get_mut(index).unwrap();
+
+                            if !global.is_internal() {
+                                None
+                            } else {
+                                Some(global)
+                            }
+                        } else {
+                            // Create automatic global module
+                            let mut global = Module::new();
+                            global.set_internal(true);
+                            mods.push(crate::engine::KEYWORD_GLOBAL, global);
+                            Some(mods.get_mut(mods.len() - 1).unwrap())
+                        };
+
+                        if let Some(global) = global {
+                            let global = Shared::get_mut(global).unwrap();
+                            global.set_var(name.clone(), value.clone());
+                            global.build_index();
+                        }
+                    }
+
                     (
                         name.to_string().into(),
                         if *export { Some(name.clone()) } else { None },

src/module/mod.rs

@@ -128,6 +128,8 @@ fn calc_native_fn_hash<'a>(
 pub struct Module {
     /// ID identifying the module.
     id: Option<Identifier>,
+    /// Is this module internal?
+    internal: bool,
     /// Sub-modules.
     modules: BTreeMap<Identifier, Shared<Module>>,
     /// [`Module`] variables.
@@ -156,6 +158,7 @@ impl Default for Module {
     fn default() -> Self {
         Self {
             id: None,
+            internal: false,
             modules: Default::default(),
             variables: Default::default(),
             all_variables: Default::default(),
@@ -301,8 +304,23 @@ impl Module {
     /// assert_eq!(module.id(), Some("hello"));
     /// ```
     #[inline(always)]
-    pub fn set_id<S: Into<Identifier>>(&mut self, id: Option<S>) {
+    pub fn set_id<S: Into<Identifier>>(&mut self, id: Option<S>) -> &mut Self {
         self.id = id.map(|s| s.into());
+        self
+    }
+
+    /// Is the [`Module`] internal?
+    #[allow(dead_code)]
+    #[inline(always)]
+    pub(crate) fn is_internal(&self) -> bool {
+        self.internal
+    }
+
+    /// Set the interal status of the [`Module`].
+    #[inline(always)]
+    pub(crate) fn set_internal(&mut self, value: bool) -> &mut Self {
+        self.internal = value;
+        self
     }
 
     /// Is the [`Module`] empty?

tests/functions.rs

@@ -62,7 +62,22 @@ fn test_functions_namespaces() -> Result<(), Box<EvalAltResult>> {
     assert_eq!(engine.eval::<INT>("test()")?, 42);
 
     #[cfg(not(feature = "no_function"))]
-    assert_eq!(engine.eval::<INT>("fn test() { 123 } test()")?, 123);
+    {
+        assert_eq!(engine.eval::<INT>("fn test() { 123 } test()")?, 123);
+
+        assert_eq!(
+            engine.eval::<INT>(
+                r"
+                    const ANSWER = 42;
+
+                    fn foo() { global::ANSWER }
+                    
+                    foo()
+                "
+            )?,
+            42
+        );
+    }
 
     Ok(())
 }