Implement module-qualified functions.

src/engine.rs

@@ -395,7 +395,7 @@ fn search_scope<'a>(
         };
 
         Ok((
-            module.get_qualified_variable_mut(name, modules.as_ref(), pos)?,
+            module.get_qualified_var_mut(name, modules.as_ref(), pos)?,
             // Module variables are constant
             ScopeEntryType::Constant,
         ))
@@ -469,13 +469,11 @@ impl Engine {
     }
 
     /// Universal method for calling functions either registered with the `Engine` or written in Rhai
-    // TODO - handle moduled function call
     pub(crate) fn call_fn_raw(
         &self,
         scope: Option<&mut Scope>,
         fn_lib: &FunctionsLib,
         fn_name: &str,
-        modules: &ModuleRef,
         args: &mut FnCallArgs,
         def_val: Option<&Dynamic>,
         pos: Position,
@@ -643,7 +641,6 @@ impl Engine {
         &self,
         fn_lib: &FunctionsLib,
         fn_name: &str,
-        modules: &ModuleRef,
         args: &mut FnCallArgs,
         def_val: Option<&Dynamic>,
         pos: Position,
@@ -651,28 +648,19 @@ impl Engine {
     ) -> Result<Dynamic, Box<EvalAltResult>> {
         match fn_name {
             // type_of
-            KEYWORD_TYPE_OF
-                if modules.is_none()
-                    && args.len() == 1
-                    && !self.has_override(fn_lib, KEYWORD_TYPE_OF) =>
-            {
+            KEYWORD_TYPE_OF if args.len() == 1 && !self.has_override(fn_lib, KEYWORD_TYPE_OF) => {
                 Ok(self.map_type_name(args[0].type_name()).to_string().into())
             }
 
             // eval - reaching this point it must be a method-style call
-            KEYWORD_EVAL
-                if modules.is_none()
-                    && args.len() == 1
-                    && !self.has_override(fn_lib, KEYWORD_EVAL) =>
-            {
+            KEYWORD_EVAL if args.len() == 1 && !self.has_override(fn_lib, KEYWORD_EVAL) => {
                 Err(Box::new(EvalAltResult::ErrorRuntime(
                     "'eval' should not be called in method style. Try eval(...);".into(),
                     pos,
                 )))
             }
-
             // Normal method call
-            _ => self.call_fn_raw(None, fn_lib, fn_name, modules, args, def_val, pos, level),
+            _ => self.call_fn_raw(None, fn_lib, fn_name, args, def_val, pos, level),
         }
     }
 
@@ -767,7 +755,7 @@ impl Engine {
                     let def_val = def_val.as_deref();
                     // A function call is assumed to have side effects, so the value is changed
                     // TODO - Remove assumption of side effects by checking whether the first parameter is &mut
-                    self.exec_fn_call(fn_lib, fn_name, &None, &mut args, def_val, *pos, 0).map(|v| (v, true))
+                    self.exec_fn_call(fn_lib, fn_name, &mut args, def_val, *pos, 0).map(|v| (v, true))
                 }
                 // xxx.module::fn_name(...) - syntax error
                 Expr::FnCall(_,_,_,_,_) => unreachable!(),
@@ -788,13 +776,13 @@ impl Engine {
                 Expr::Property(id, pos) if new_val.is_some() => {
                     let fn_name = make_setter(id);
                     let mut args = [obj, new_val.as_mut().unwrap()];
-                    self.exec_fn_call(fn_lib, &fn_name, &None, &mut args, None, *pos, 0).map(|v| (v, true))
+                    self.exec_fn_call(fn_lib, &fn_name, &mut args, None, *pos, 0).map(|v| (v, true))
                 }
                 // xxx.id
                 Expr::Property(id, pos) => {
                     let fn_name = make_getter(id);
                     let mut args = [obj];
-                    self.exec_fn_call(fn_lib, &fn_name, &None, &mut args, None, *pos, 0).map(|v| (v, false))
+                    self.exec_fn_call(fn_lib, &fn_name, &mut args, None, *pos, 0).map(|v| (v, false))
                 }
                 // {xxx:map}.idx_lhs[idx_expr]
                 Expr::Index(dot_lhs, dot_rhs, pos) |
@@ -824,7 +812,7 @@ impl Engine {
 
                     let indexed_val = &mut (if let Expr::Property(id, pos) = dot_lhs.as_ref() {
                         let fn_name = make_getter(id);
-                        self.exec_fn_call(fn_lib, &fn_name, &None, &mut args[..1], None, *pos, 0)?
+                        self.exec_fn_call(fn_lib, &fn_name, &mut args[..1], None, *pos, 0)?
                     } else {
                         // Syntax error
                         return Err(Box::new(EvalAltResult::ErrorDotExpr(
@@ -842,7 +830,7 @@ impl Engine {
                             let fn_name = make_setter(id);
                             // Re-use args because the first &mut parameter will not be consumed
                             args[1] = indexed_val;
-                            self.exec_fn_call(fn_lib, &fn_name, &None, &mut args, None, *pos, 0).or_else(|err| match *err {
+                            self.exec_fn_call(fn_lib, &fn_name, &mut args, None, *pos, 0).or_else(|err| match *err {
                                 // If there is no setter, no need to feed it back because the property is read-only
                                 EvalAltResult::ErrorDotExpr(_,_) => Ok(Default::default()),
                                 err => Err(Box::new(err))
@@ -1073,7 +1061,7 @@ impl Engine {
                     let pos = rhs.position();
 
                     if self
-                        .call_fn_raw(None, fn_lib, "==", &None, args, def_value, pos, level)?
+                        .call_fn_raw(None, fn_lib, "==", args, def_value, pos, level)?
                         .as_bool()
                         .unwrap_or(false)
                     {
@@ -1213,12 +1201,26 @@ impl Engine {
 
                 let mut args: Vec<_> = arg_values.iter_mut().collect();
 
-                // eval - only in function call style
-                if fn_name.as_ref() == KEYWORD_EVAL
-                    && modules.is_none()
+                if let Some(modules) = modules {
+                    // Module-qualified function call
+                    let hash = calc_fn_hash(fn_name, args.iter().map(|a| a.type_id()));
+
+                    let (id, root_pos) = modules.get(0); // First module
+
+                    let module = scope.find_module(id).ok_or_else(|| {
+                        Box::new(EvalAltResult::ErrorModuleNotFound(id.into(), *root_pos))
+                    })?;
+                    match module.get_qualified_fn(fn_name, hash, modules.as_ref(), *pos) {
+                        Ok(func) => func(&mut args, *pos)
+                            .map_err(|err| EvalAltResult::set_position(err, *pos)),
+                        Err(_) if def_val.is_some() => Ok(def_val.as_deref().unwrap().clone()),
+                        Err(err) => Err(err),
+                    }
+                } else if fn_name.as_ref() == KEYWORD_EVAL
                     && args.len() == 1
                     && !self.has_override(fn_lib, KEYWORD_EVAL)
                 {
+                    // eval - only in function call style
                     let prev_len = scope.len();
 
                     // Evaluate the text string as a script
@@ -1231,12 +1233,12 @@ impl Engine {
                         state.always_search = true;
                     }
 
-                    return result;
+                    result
+                } else {
+                    // Normal function call - except for eval (handled above)
+                    let def_value = def_val.as_deref();
+                    self.exec_fn_call(fn_lib, fn_name, &mut args, def_value, *pos, level)
                 }
-
-                // Normal function call - except for eval (handled above)
-                let def_value = def_val.as_deref();
-                self.exec_fn_call(fn_lib, fn_name, modules, &mut args, def_value, *pos, level)
             }
 
             Expr::In(lhs, rhs, _) => {
@@ -1472,8 +1474,9 @@ impl Engine {
                     .try_cast::<String>()
                 {
                     let mut module = Module::new();
-                    module.set_variable("kitty", "foo".to_string());
-                    module.set_variable("path", path);
+                    module.set_var("kitty", "foo".to_string());
+                    module.set_var("path", path);
+                    module.set_fn_1_mut("calc", |x: &mut String| Ok(x.len() as crate::parser::INT));
 
                     // TODO - avoid copying module name in inner block?
                     let mod_name = name.as_ref().clone();

src/module.rs

@@ -1,12 +1,14 @@
 //! Module defining external-loaded modules for Rhai.
 
 use crate::any::{Dynamic, Variant};
-use crate::engine::{FnAny, FunctionsLib};
+use crate::calc_fn_hash;
+use crate::engine::{FnAny, FnCallArgs, FunctionsLib};
 use crate::result::EvalAltResult;
 use crate::token::Position;
+use crate::token::Token;
 use crate::utils::StaticVec;
 
-use crate::stdlib::{collections::HashMap, fmt, string::String};
+use crate::stdlib::{any::TypeId, collections::HashMap, fmt, iter::empty, mem, string::String};
 
 /// An imported module, which may contain variables, sub-modules,
 /// external Rust functions, and script-defined functions.
@@ -51,34 +53,34 @@ impl Module {
     }
 
     /// Does a variable exist in the module?
-    pub fn contains_variable(&self, name: &str) -> bool {
+    pub fn contains_var(&self, name: &str) -> bool {
         self.variables.contains_key(name)
     }
 
     /// Get the value of a module variable.
-    pub fn get_variable_value<T: Variant + Clone>(&self, name: &str) -> Option<T> {
-        self.get_variable(name).and_then(|v| v.try_cast::<T>())
+    pub fn get_var_value<T: Variant + Clone>(&self, name: &str) -> Option<T> {
+        self.get_var(name).and_then(|v| v.try_cast::<T>())
     }
 
     /// Get a module variable.
-    pub fn get_variable(&self, name: &str) -> Option<Dynamic> {
+    pub fn get_var(&self, name: &str) -> Option<Dynamic> {
         self.variables.get(name).cloned()
     }
 
     /// Get a mutable reference to a module variable.
-    pub fn get_variable_mut(&mut self, name: &str) -> Option<&mut Dynamic> {
+    pub fn get_var_mut(&mut self, name: &str) -> Option<&mut Dynamic> {
         self.variables.get_mut(name)
     }
 
     /// Set a variable into the module.
     ///
     /// If there is an existing variable of the same name, it is replaced.
-    pub fn set_variable<K: Into<String>, T: Into<Dynamic>>(&mut self, name: K, value: T) {
+    pub fn set_var<K: Into<String>, T: Into<Dynamic>>(&mut self, name: K, value: T) {
         self.variables.insert(name.into(), value.into());
     }
 
     /// Get a mutable reference to a modules-qualified variable.
-    pub(crate) fn get_qualified_variable_mut(
+    pub(crate) fn get_qualified_var_mut(
         &mut self,
         name: &str,
         modules: &StaticVec<(String, Position)>,
@@ -86,7 +88,7 @@ impl Module {
     ) -> Result<&mut Dynamic, Box<EvalAltResult>> {
         Ok(self
             .get_qualified_module_mut(modules)?
-            .get_variable_mut(name)
+            .get_var_mut(name)
             .ok_or_else(|| Box::new(EvalAltResult::ErrorVariableNotFound(name.into(), pos)))?)
     }
 
@@ -131,4 +133,245 @@ impl Module {
 
         Ok(module)
     }
+
+    /// Does the particular Rust function exist in the module?
+    ///
+    /// The `u64` hash is calculated by the function `crate::calc_fn_hash`.
+    /// It is also returned by the `set_fn_XXX` calls.
+    pub fn contains_fn(&self, hash: u64) -> bool {
+        self.functions.contains_key(&hash)
+    }
+
+    /// Set a Rust function into the module, returning a hash key.
+    ///
+    /// If there is an existing Rust function of the same hash, it is replaced.
+    pub fn set_fn(&mut self, fn_name: &str, params: &[TypeId], func: Box<FnAny>) -> u64 {
+        let hash = calc_fn_hash(fn_name, params.iter().cloned());
+        self.functions.insert(hash, func);
+        hash
+    }
+
+    /// Set a Rust function taking no parameters into the module, returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_0<T: Into<Dynamic>>(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn() -> Result<T, Box<EvalAltResult>> + 'static,
+        #[cfg(feature = "sync")] func: impl Fn() -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(fn_name, empty());
+        let f = move |_: &mut FnCallArgs, _: Position| func().map(|v| v.into());
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking one parameter into the module, returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_1<A: Variant + Clone, T: Into<Dynamic>>(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(A) -> Result<T, Box<EvalAltResult>> + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(A) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(fn_name, [TypeId::of::<A>()].iter().cloned());
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            func(mem::take(args[0]).cast::<A>()).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking one mutable parameter into the module, returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_1_mut<A: Variant + Clone, T: Into<Dynamic>>(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(&mut A) -> Result<T, Box<EvalAltResult>> + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(&mut A) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(fn_name, [TypeId::of::<A>()].iter().cloned());
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            func(args[0].downcast_mut::<A>().unwrap()).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking two parameters into the module, returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_2<A: Variant + Clone, B: Variant + Clone, T: Into<Dynamic>>(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(A, B) -> Result<T, Box<EvalAltResult>> + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(A, B) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(
+            fn_name,
+            [TypeId::of::<A>(), TypeId::of::<B>()].iter().cloned(),
+        );
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            let a = mem::take(args[0]).cast::<A>();
+            let b = mem::take(args[1]).cast::<B>();
+
+            func(a, b).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking two parameters (the first one mutable) into the module,
+    /// returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_2_mut<A: Variant + Clone, B: Variant + Clone, T: Into<Dynamic>>(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(&mut A, B) -> Result<T, Box<EvalAltResult>>
+            + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(&mut A, B) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(
+            fn_name,
+            [TypeId::of::<A>(), TypeId::of::<B>()].iter().cloned(),
+        );
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            let b = mem::take(args[1]).cast::<B>();
+            let a = args[0].downcast_mut::<A>().unwrap();
+
+            func(a, b).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking three parameters into the module, returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_3<
+        A: Variant + Clone,
+        B: Variant + Clone,
+        C: Variant + Clone,
+        T: Into<Dynamic>,
+    >(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(A, B, C) -> Result<T, Box<EvalAltResult>> + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(A, B, C) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(
+            fn_name,
+            [TypeId::of::<A>(), TypeId::of::<B>(), TypeId::of::<C>()]
+                .iter()
+                .cloned(),
+        );
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            let a = mem::take(args[0]).cast::<A>();
+            let b = mem::take(args[1]).cast::<B>();
+            let c = mem::take(args[2]).cast::<C>();
+
+            func(a, b, c).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Set a Rust function taking three parameters (the first one mutable) into the module,
+    /// returning a hash key.
+    ///
+    /// If there is a similar existing Rust function, it is replaced.
+    pub fn set_fn_3_mut<
+        A: Variant + Clone,
+        B: Variant + Clone,
+        C: Variant + Clone,
+        T: Into<Dynamic>,
+    >(
+        &mut self,
+        fn_name: &str,
+        #[cfg(not(feature = "sync"))] func: impl Fn(&mut A, B, C) -> Result<T, Box<EvalAltResult>>
+            + 'static,
+        #[cfg(feature = "sync")] func: impl Fn(&mut A, B, C) -> Result<T, Box<EvalAltResult>>
+            + Send
+            + Sync
+            + 'static,
+    ) -> u64 {
+        let hash = calc_fn_hash(
+            fn_name,
+            [TypeId::of::<A>(), TypeId::of::<B>(), TypeId::of::<C>()]
+                .iter()
+                .cloned(),
+        );
+
+        let f = move |args: &mut FnCallArgs, _: Position| {
+            let b = mem::take(args[1]).cast::<B>();
+            let c = mem::take(args[2]).cast::<C>();
+            let a = args[0].downcast_mut::<A>().unwrap();
+
+            func(a, b, c).map(|v| v.into())
+        };
+        self.functions.insert(hash, Box::new(f));
+        hash
+    }
+
+    /// Get a Rust function.
+    ///
+    /// The `u64` hash is calculated by the function `crate::calc_fn_hash`.
+    /// It is also returned by the `set_fn_XXX` calls.
+    pub fn get_fn(&self, hash: u64) -> Option<&Box<FnAny>> {
+        self.functions.get(&hash)
+    }
+
+    /// Get a modules-qualified function.
+    ///
+    /// The `u64` hash is calculated by the function `crate::calc_fn_hash`.
+    /// It is also returned by the `set_fn_XXX` calls.
+    pub(crate) fn get_qualified_fn(
+        &mut self,
+        name: &str,
+        hash: u64,
+        modules: &StaticVec<(String, Position)>,
+        pos: Position,
+    ) -> Result<&Box<FnAny>, Box<EvalAltResult>> {
+        Ok(self
+            .get_qualified_module_mut(modules)?
+            .get_fn(hash)
+            .ok_or_else(|| {
+                let mut fn_name: String = Default::default();
+
+                modules.iter().for_each(|(n, _)| {
+                    fn_name.push_str(n);
+                    fn_name.push_str(Token::DoubleColon.syntax().as_ref());
+                });
+
+                fn_name.push_str(name);
+
+                Box::new(EvalAltResult::ErrorFunctionNotFound(fn_name, pos))
+            })?)
+    }
 }

src/parser.rs

@@ -589,13 +589,8 @@ impl Expr {
                 _ => false,
             },
 
-            Self::Variable(_, None, _, _) => match token {
-                Token::LeftBracket | Token::LeftParen => true,
-                #[cfg(not(feature = "no_module"))]
-                Token::DoubleColon => true,
-                _ => false,
-            },
             Self::Variable(_, _, _, _) => match token {
+                Token::LeftBracket | Token::LeftParen => true,
                 #[cfg(not(feature = "no_module"))]
                 Token::DoubleColon => true,
                 _ => false,

src/scope.rs

@@ -172,7 +172,7 @@ impl<'a> Scope<'a> {
     /// Add (push) a new module to the Scope.
     ///
     /// Modules are used for accessing member variables, functions and plugins under a namespace.
-    pub(crate) fn push_module<K: Into<Cow<'a, str>>>(&mut self, name: K, value: Module) {
+    pub fn push_module<K: Into<Cow<'a, str>>>(&mut self, name: K, value: Module) {
         self.push_dynamic_value(
             name,
             EntryType::Module,

tests/modules.rs

@@ -1,33 +1,58 @@
 #![cfg(not(feature = "no_module"))]
-use rhai::{EvalAltResult, Module, Scope, INT};
+use rhai::{Engine, EvalAltResult, Module, Scope, INT};
 
 #[test]
 fn test_module() {
     let mut module = Module::new();
-    module.set_variable("kitty", 42 as INT);
+    module.set_var("answer", 42 as INT);
 
-    assert!(module.contains_variable("kitty"));
-    assert_eq!(module.get_variable_value::<INT>("kitty").unwrap(), 42);
+    assert!(module.contains_var("answer"));
+    assert_eq!(module.get_var_value::<INT>("answer").unwrap(), 42);
 }
 
 #[test]
-fn test_sub_module() {
+fn test_sub_module() -> Result<(), Box<EvalAltResult>> {
     let mut module = Module::new();
 
     let mut sub_module = Module::new();
 
     let mut sub_module2 = Module::new();
-    sub_module2.set_variable("kitty", 42 as INT);
+    sub_module2.set_var("answer", 41 as INT);
+    let hash = sub_module2.set_fn_1("inc", |x: INT| Ok(x + 1));
 
-    sub_module.set_sub_module("world", sub_module2);
-    module.set_sub_module("hello", sub_module);
+    sub_module.set_sub_module("universe", sub_module2);
+    module.set_sub_module("life", sub_module);
 
-    assert!(module.contains_sub_module("hello"));
-    let m = module.get_sub_module("hello").unwrap();
+    assert!(module.contains_sub_module("life"));
+    let m = module.get_sub_module("life").unwrap();
 
-    assert!(m.contains_sub_module("world"));
-    let m2 = m.get_sub_module("world").unwrap();
+    assert!(m.contains_sub_module("universe"));
+    let m2 = m.get_sub_module("universe").unwrap();
 
-    assert!(m2.contains_variable("kitty"));
-    assert_eq!(m2.get_variable_value::<INT>("kitty").unwrap(), 42);
+    assert!(m2.contains_var("answer"));
+    assert!(m2.contains_fn(hash));
+
+    assert_eq!(m2.get_var_value::<INT>("answer").unwrap(), 41);
+
+    let mut engine = Engine::new();
+    let mut scope = Scope::new();
+
+    scope.push_module("question", module);
+
+    assert_eq!(
+        engine.eval_expression_with_scope::<INT>(
+            &mut scope,
+            "question::life::universe::answer + 1"
+        )?,
+        42
+    );
+    assert_eq!(
+        engine.eval_expression_with_scope::<INT>(
+            &mut scope,
+            "question::life::universe::inc(question::life::universe::answer)"
+        )?,
+        42
+    );
+
+    Ok(())
 }