Add get_fn_metadata_list.

RELEASES.md

@@ -39,6 +39,7 @@ New features
 * `Module::set_getter_fn`, `Module::set_setter_fn`, `Module::set_indexer_get_fn`, `Module::set_indexer_set_fn` all expose the function to the global namespace by default. This is convenient when registering an API for a custom type.
 * New `Module::update_fn_metadata` to update a module function's parameter names and types.
 * New `#[rhai_fn(global)]` and `#[rhai_fn(internal)]` attributes to determine whether a function defined in a plugin module should be exposed to the global namespace. This is convenient when defining an API for a custom type.
+* New `get_fn_metadata_list` to get the metadata of all script-defined functions in scope.
 
 Enhancements
 ------------

doc/src/language/functions.md

@@ -101,21 +101,6 @@ a statement in the script can freely call a function defined afterwards.
 This is similar to Rust and many other modern languages, such as JavaScript's `function` keyword.
 
 
-`is_def_fn`
------------
-
-Use `is_def_fn` to detect if a Rhai function is defined (and therefore callable), based on its name
-and the number of parameters.
-
-```rust
-fn foo(x) { x + 1 }
-
-is_def_fn("foo", 1) == true;
-
-is_def_fn("bar", 1) == false;
-```
-
-
 Arguments are Passed by Value
 ----------------------------
 
@@ -159,3 +144,43 @@ x == 42;            // 'x' is changed!
 
 change();           // <- error: `this` is unbound
 ```
+
+
+`is_def_fn`
+-----------
+
+Use `is_def_fn` to detect if a Rhai function is defined (and therefore callable), based on its name
+and the number of parameters.
+
+```rust
+fn foo(x) { x + 1 }
+
+is_def_fn("foo", 1) == true;
+
+is_def_fn("bar", 1) == false;
+```
+
+
+Metadata
+--------
+
+The function `get_fn_metadata_list` is a _reflection_ API that returns an array of the metadata
+of all script-defined functions in scope.
+
+Functions from the following sources are returned, in order:
+
+1) Encapsulated script environment (e.g. when loading a [module] from a script file),
+2) Current script,
+3) [Modules] imported via the [`import`] statement (latest imports first),
+4) [Modules] added via [`Engine::register_module`]({{rootUrl}}/rust/modules/create.md) (latest registrations first)
+
+The return value is an [array] of [object maps] (so `get_fn_metadata_list` is not available under
+[`no_index`] or [`no_object`]), containing the following fields:
+
+| Field          |         Type         | Optional? | Description                                                            |
+| -------------- | :------------------: | :-------: | ---------------------------------------------------------------------- |
+| `namespace`    |       [string]       |    yes    | the module _namespace_ if the function is defined within a module      |
+| `access`       |       [string]       |    no     | `"public"` if the function is public,<br/>`"private"` if it is private |
+| `name`         |       [string]       |    no     | function name                                                          |
+| `params`       | [array] of [strings] |    no     | parameter names                                                        |
+| `is_anonymous` |        `bool`        |    no     | is this function an anonymous function?                                |

src/engine.rs

@@ -97,11 +97,11 @@ impl Imports {
     }
     /// Get an iterator to this stack of imported modules in reverse order.
     #[allow(dead_code)]
-    pub fn iter(&self) -> impl Iterator<Item = (&str, Shared<Module>)> {
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = (ImmutableString, Shared<Module>)> + 'a {
         self.0.iter().flat_map(|lib| {
             lib.iter()
                 .rev()
-                .map(|(name, module)| (name.as_str(), module.clone()))
+                .map(|(name, module)| (name.clone(), module.clone()))
         })
     }
     /// Get an iterator to this stack of imported modules in reverse order.

src/module/mod.rs

@@ -1500,10 +1500,16 @@ impl Module {
         )
     }
 
+    /// Get an iterator to the sub-modules in the module.
+    #[inline(always)]
+    pub fn iter_sub_modules(&self) -> impl Iterator<Item = (&str, Shared<Module>)> {
+        self.modules.iter().map(|(k, m)| (k.as_str(), m.clone()))
+    }
+
     /// Get an iterator to the variables in the module.
     #[inline(always)]
-    pub fn iter_var(&self) -> impl Iterator<Item = (&String, &Dynamic)> {
+    pub fn iter_var(&self) -> impl Iterator<Item = (&str, &Dynamic)> {
-        self.variables.iter()
+        self.variables.iter().map(|(k, v)| (k.as_str(), v))
     }
 
     /// Get an iterator to the functions in the module.

src/packages/fn_basic.rs

@@ -1,5 +1,12 @@
+use crate::module::SharedScriptFnDef;
 use crate::plugin::*;
-use crate::{def_package, FnPtr};
+use crate::stdlib::iter::empty;
+use crate::{calc_script_fn_hash, def_package, FnPtr, ImmutableString, NativeCallContext, INT};
+
+#[cfg(not(feature = "no_function"))]
+#[cfg(not(feature = "no_index"))]
+#[cfg(not(feature = "no_object"))]
+use crate::{stdlib::collections::HashMap, Array, Map};
 
 def_package!(crate:BasicFnPackage:"Basic Fn functions.", lib, {
     combine_with_exported_module!(lib, "FnPtr", fn_ptr_functions);
@@ -13,10 +20,111 @@ mod fn_ptr_functions {
     }
 
     #[cfg(not(feature = "no_function"))]
-    pub mod anonymous {
+    pub mod functions {
         #[rhai_fn(name = "is_anonymous", get = "is_anonymous")]
         pub fn is_anonymous(f: &mut FnPtr) -> bool {
             f.is_anonymous()
         }
+
+        pub fn is_def_fn(ctx: NativeCallContext, fn_name: &str, num_params: INT) -> bool {
+            if num_params < 0 {
+                false
+            } else {
+                let hash_script = calc_script_fn_hash(empty(), fn_name, num_params as usize);
+                ctx.engine()
+                    .has_override(ctx.mods, ctx.lib, 0, hash_script, true)
+            }
+        }
+    }
+
+    #[cfg(not(feature = "no_function"))]
+    #[cfg(not(feature = "no_index"))]
+    #[cfg(not(feature = "no_object"))]
+    pub mod functions_and_maps {
+        pub fn get_fn_metadata_list(ctx: NativeCallContext) -> Array {
+            collect_fn_metadata(ctx)
+        }
     }
 }
+
+#[cfg(not(feature = "no_function"))]
+#[cfg(not(feature = "no_index"))]
+#[cfg(not(feature = "no_object"))]
+fn collect_fn_metadata(ctx: NativeCallContext) -> Array {
+    // Create a metadata record for a function.
+    fn make_metadata(
+        dict: &HashMap<String, ImmutableString>,
+        namespace: Option<ImmutableString>,
+        f: SharedScriptFnDef,
+    ) -> Map {
+        let mut map = Map::with_capacity(6);
+
+        if let Some(ns) = namespace {
+            map.insert(dict["namespace"].clone(), ns.into());
+        }
+        map.insert(dict["name"].clone(), f.name.clone().into());
+        map.insert(
+            dict["access"].clone(),
+            match f.access {
+                FnAccess::Public => dict["public"].clone(),
+                FnAccess::Private => dict["private"].clone(),
+            }
+            .into(),
+        );
+        map.insert(
+            dict["is_anonymous"].clone(),
+            f.name.starts_with(crate::engine::FN_ANONYMOUS).into(),
+        );
+        map.insert(
+            dict["params"].clone(),
+            f.params
+                .iter()
+                .cloned()
+                .map(Into::<Dynamic>::into)
+                .collect::<Array>()
+                .into(),
+        );
+
+        map.into()
+    }
+
+    // Recursively scan modules for script-defined functions.
+    fn scan_module(
+        list: &mut Array,
+        dict: &HashMap<String, ImmutableString>,
+        namespace: ImmutableString,
+        module: &Module,
+    ) {
+        module.iter_script_fn().for_each(|(_, _, _, _, f)| {
+            list.push(make_metadata(dict, Some(namespace.clone()), f).into())
+        });
+        module.iter_sub_modules().for_each(|(ns, m)| {
+            let ns: ImmutableString = format!("{}::{}", namespace, ns).into();
+            scan_module(list, dict, ns, m.as_ref())
+        });
+    }
+
+    // Intern strings
+    let mut dict = HashMap::<String, ImmutableString>::with_capacity(8);
+    dict.insert("namespace".into(), "namespace".into());
+    dict.insert("name".into(), "name".into());
+    dict.insert("access".into(), "access".into());
+    dict.insert("public".into(), "public".into());
+    dict.insert("private".into(), "private".into());
+    dict.insert("is_anonymous".into(), "is_anonymous".into());
+    dict.insert("params".into(), "params".into());
+
+    let mut list: Array = Default::default();
+
+    ctx.lib
+        .iter()
+        .flat_map(|m| m.iter_script_fn())
+        .for_each(|(_, _, _, _, f)| list.push(make_metadata(&dict, None, f).into()));
+
+    if let Some(mods) = ctx.mods {
+        mods.iter()
+            .for_each(|(ns, m)| scan_module(&mut list, &dict, ns, m.as_ref()));
+    }
+
+    list
+}

src/packages/pkg_core.rs

@@ -4,34 +4,9 @@ use super::iter_basic::BasicIteratorPackage;
 use super::logic::LogicPackage;
 use super::string_basic::BasicStringPackage;
 
-use crate::fn_native::{CallableFunction, FnCallArgs};
+use crate::def_package;
-use crate::stdlib::{any::TypeId, boxed::Box, iter::empty};
-use crate::{
-    calc_script_fn_hash, def_package, FnAccess, FnNamespace, ImmutableString, NativeCallContext,
-    INT,
-};
 
 def_package!(crate:CorePackage:"_Core_ package containing basic facilities.", lib, {
-    #[cfg(not(feature = "no_function"))]
-    {
-        let f = |ctx: NativeCallContext, args: &mut FnCallArgs| {
-            let num_params = args[1].clone().cast::<INT>();
-            let fn_name = args[0].as_str().unwrap();
-
-            Ok(if num_params < 0 {
-                false.into()
-            } else {
-                let hash_script = calc_script_fn_hash(empty(), fn_name, num_params as usize);
-                ctx.engine().has_override(ctx.mods, ctx.lib, 0, hash_script, true).into()
-            })
-        };
-
-        lib.set_fn("is_def_fn", FnNamespace::Global, FnAccess::Public,
-            Some(&["fn_name: &str", "num_params: INT"]),
-            &[TypeId::of::<ImmutableString>(), TypeId::of::<INT>()],
-            CallableFunction::from_method(Box::new(f)));
-    }
-
     ArithmeticPackage::init(lib);
     LogicPackage::init(lib);
     BasicStringPackage::init(lib);