Pre-calculate index for module-qualified calls.

README.md

@@ -2158,7 +2158,7 @@ let ast = engine.compile(r#"
 "#)?;
 
 // Convert the 'AST' into a module, using the 'Engine' to evaluate it first
-let module = Module::eval_ast_as_new(&ast, &engine)?;
+let module = Module::eval_ast_as_new(Scope::new(), &ast, &engine)?;
 
 // 'module' now can be loaded into a custom 'Scope' for future use.  It contains:
 //   - sub-module: 'extra'

src/engine.rs

@@ -434,7 +434,7 @@ fn default_print(s: &str) {
 fn search_scope<'a>(
     scope: &'a mut Scope,
     name: &str,
-    #[cfg(not(feature = "no_module"))] mut modules: &Option<Box<ModuleRef>>,
+    #[cfg(not(feature = "no_module"))] modules: &Option<Box<ModuleRef>>,
     #[cfg(feature = "no_module")] _: &Option<ModuleRef>,
     index: Option<NonZeroUsize>,
     pos: Position,
@@ -444,7 +444,7 @@ fn search_scope<'a>(
         if let Some(modules) = modules {
             let (id, root_pos) = modules.get(0);
 
-            let module = if let Some(index) = index {
+            let module = if let Some(index) = modules.index() {
                 scope
                     .get_mut(scope.len() - index.get())
                     .0
@@ -1369,9 +1369,17 @@ impl Engine {
 
                 let (id, root_pos) = modules.get(0); // First module
 
-                let module = scope.find_module(id).ok_or_else(|| {
+                let module = if let Some(index) = modules.index() {
-                    Box::new(EvalAltResult::ErrorModuleNotFound(id.into(), *root_pos))
+                    scope
-                })?;
+                        .get_mut(scope.len() - index.get())
+                        .0
+                        .downcast_mut::<Module>()
+                        .unwrap()
+                } else {
+                    scope.find_module(id).ok_or_else(|| {
+                        Box::new(EvalAltResult::ErrorModuleNotFound(id.into(), *root_pos))
+                    })?
+                };
 
                 // First search in script-defined functions (can override built-in)
                 if let Some(fn_def) = module.get_qualified_scripted_fn(modules.key()) {
@@ -1623,9 +1631,8 @@ impl Engine {
                     {
                         if let Some(resolver) = self.module_resolver.as_ref() {
                             // Use an empty scope to create a module
-                            let mut mod_scope = Scope::new();
                             let module =
-                                resolver.resolve(self, mod_scope, &path, expr.position())?;
+                                resolver.resolve(self, Scope::new(), &path, expr.position())?;
 
                             // TODO - avoid copying module name in inner block?
                             let mod_name = name.as_ref().clone();
@@ -1649,18 +1656,18 @@ impl Engine {
                     let mut found = false;
 
                     // Mark scope variables as public
-                    match scope.get_index(id) {
+                    if let Some(index) = scope
-                        Some((index, ScopeEntryType::Normal))
+                        .get_index(id)
-                        | Some((index, ScopeEntryType::Constant)) => {
+                        .map(|(i, _)| i)
-                            let alias = rename
+                        .or_else(|| scope.get_module_index(id))
-                                .as_ref()
+                    {
-                                .map(|(n, _)| n.clone())
+                        let alias = rename
-                                .unwrap_or_else(|| id.clone());
+                            .as_ref()
-                            scope.set_entry_alias(index, alias);
+                            .map(|(n, _)| n.clone())
-                            found = true;
+                            .unwrap_or_else(|| id.clone());
-                        }
+
-                        Some((_, ScopeEntryType::Module)) => unreachable!(),
+                        scope.set_entry_alias(index, alias);
-                        _ => (),
+                        found = true;
                     }
 
                     if !found {

src/module.rs

@@ -17,6 +17,7 @@ use crate::stdlib::{
     fmt,
     iter::{empty, repeat},
     mem,
+    num::NonZeroUsize,
     ops::{Deref, DerefMut},
     rc::Rc,
     string::{String, ToString},
@@ -568,12 +569,11 @@ impl Module {
     ///
     /// ```
     /// # fn main() -> Result<(), Box<rhai::EvalAltResult>> {
-    /// use rhai::{Engine, Module};
+    /// use rhai::{Engine, Module, Scope};
     ///
     /// let engine = Engine::new();
-    /// let mut scope = Scope::new();
+    /// let ast = engine.compile("let answer = 42; export answer;")?;
-    /// let ast = engine.compile("let answer = 42;")?;
+    /// let module = Module::eval_ast_as_new(Scope::new(), &ast, &engine)?;
-    /// let module = Module::eval_ast_as_new(scope, &ast, &engine)?;
     /// assert!(module.contains_var("answer"));
     /// assert_eq!(module.get_var_value::<i64>("answer").unwrap(), 42);
     /// # Ok(())
@@ -599,14 +599,14 @@ impl Module {
                     ScopeEntryType::Normal | ScopeEntryType::Constant if alias.is_some() => {
                         module.variables.insert(*alias.unwrap(), value);
                     }
-                    // Variables with no alias are private and not exported
-                    ScopeEntryType::Normal | ScopeEntryType::Constant => (),
                     // Modules left in the scope become sub-modules
-                    ScopeEntryType::Module => {
+                    ScopeEntryType::Module if alias.is_some() => {
                         module
                             .modules
-                            .insert(name.into_owned(), value.cast::<Module>());
+                            .insert(*alias.unwrap(), value.cast::<Module>());
                     }
+                    // Variables and modules with no alias are private and not exported
+                    _ => (),
                 }
             },
         );
@@ -830,14 +830,18 @@ mod file {
 /// 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, Hash, Default)]
-pub struct ModuleRef(StaticVec<(String, Position)>, u64);
+pub struct ModuleRef(StaticVec<(String, Position)>, Option<NonZeroUsize>, u64);
 
 impl fmt::Debug for ModuleRef {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&self.0, f)?;
 
-        if self.1 > 0 {
+        if self.2 > 0 {
-            write!(f, " -> {:0>16x}", self.1)
+            if let Some(index) = self.1 {
+                write!(f, " -> {},{:0>16x}", index, self.2)
+            } else {
+                write!(f, " -> {:0>16x}", self.2)
+            }
         } else {
             Ok(())
         }
@@ -869,16 +873,22 @@ impl fmt::Display for ModuleRef {
 
 impl From<StaticVec<(String, Position)>> for ModuleRef {
     fn from(modules: StaticVec<(String, Position)>) -> Self {
-        Self(modules, 0)
+        Self(modules, None, 0)
     }
 }
 
 impl ModuleRef {
-    pub fn key(&self) -> u64 {
+    pub(crate) fn key(&self) -> u64 {
+        self.2
+    }
+    pub(crate) fn set_key(&mut self, key: u64) {
+        self.2 = key
+    }
+    pub(crate) fn index(&self) -> Option<NonZeroUsize> {
         self.1
     }
-    pub fn set_key(&mut self, key: u64) {
+    pub(crate) fn set_index(&mut self, index: Option<NonZeroUsize>) {
-        self.1 = key
+        self.1 = index
     }
 }
 

src/parser.rs

@@ -719,6 +719,7 @@ fn parse_call_expr<'a>(
                     // Calculate hash
                     let hash = calc_fn_hash(modules.iter().map(|(m, _)| m.as_str()), &id, empty());
                     modules.set_key(hash);
+                    modules.set_index(stack.find_module(&modules.get(0).0));
                 }
             }
             return Ok(Expr::FnCall(
@@ -751,6 +752,7 @@ fn parse_call_expr<'a>(
                             repeat(EMPTY_TYPE_ID()).take(args.len()),
                         );
                         modules.set_key(hash);
+                        modules.set_index(stack.find_module(&modules.get(0).0));
                     }
                 }
                 return Ok(Expr::FnCall(
@@ -1147,14 +1149,12 @@ fn parse_primary<'a>(
             }
             // module access
             #[cfg(not(feature = "no_module"))]
-            (Expr::Variable(id, mut modules, mut index, pos), Token::DoubleColon) => {
+            (Expr::Variable(id, mut modules, index, pos), Token::DoubleColon) => {
                 match input.next().unwrap() {
                     (Token::Identifier(id2), pos2) => {
                         if let Some(ref mut modules) = modules {
                             modules.push((*id, pos));
                         } else {
-                            index = stack.find_module(id.as_ref());
-
                             let mut m: ModuleRef = Default::default();
                             m.push((*id, pos));
                             modules = Some(Box::new(m));
@@ -1181,6 +1181,7 @@ fn parse_primary<'a>(
         Expr::Variable(id, Some(modules), _, _) => {
             let hash = calc_fn_hash(modules.iter().map(|(v, _)| v.as_str()), id, empty());
             modules.set_key(hash);
+            modules.set_index(stack.find_module(&modules.get(0).0));
         }
         _ => (),
     }
@@ -2131,7 +2132,8 @@ fn parse_stmt<'a>(
         Token::LeftBrace => parse_block(input, stack, breakable, allow_stmt_expr),
 
         // fn ...
-        Token::Fn => Err(PERR::WrongFnDefinition.into_err(*pos)),
+        Token::Fn if !is_global => Err(PERR::WrongFnDefinition.into_err(*pos)),
+        Token::Fn => unreachable!(),
 
         Token::If => parse_if(input, stack, breakable, allow_stmt_expr),
         Token::While => parse_while(input, stack, allow_stmt_expr),

tests/modules.rs

@@ -114,23 +114,25 @@ fn test_module_from_ast() -> Result<(), Box<EvalAltResult>> {
         // Final variable values become constant module variable values
         foo = calc(foo);
         hello = "hello, " + foo + " worlds!";
+
+        export x as abc, foo, hello, extra as foobar;
     "#,
     )?;
 
-    let module = Module::eval_ast_as_new(&ast, &engine)?;
+    let module = Module::eval_ast_as_new(Scope::new(), &ast, &engine)?;
 
     let mut scope = Scope::new();
     scope.push_module("testing", module);
 
     assert_eq!(
-        engine.eval_expression_with_scope::<INT>(&mut scope, "testing::x")?,
+        engine.eval_expression_with_scope::<INT>(&mut scope, "testing::abc")?,
         123
     );
     assert_eq!(
         engine.eval_expression_with_scope::<INT>(&mut scope, "testing::foo")?,
         42
     );
-    assert!(engine.eval_expression_with_scope::<bool>(&mut scope, "testing::extra::foo")?);
+    assert!(engine.eval_expression_with_scope::<bool>(&mut scope, "testing::foobar::foo")?);
     assert_eq!(
         engine.eval_expression_with_scope::<String>(&mut scope, "testing::hello")?,
         "hello, 42 worlds!"