Add Module::fill_with.

RELEASES.md

@@ -2,6 +2,15 @@ Rhai Release Notes
 ==================
 
 
+Version 0.19.4
+==============
+
+New features
+------------
+
+* `Module::fill_with` to poly-fill a module with another.
+
+
 Version 0.19.3
 ==============
 

src/module/mod.rs

@@ -1125,18 +1125,10 @@ impl Module {
     /// The other module is consumed to merge into this module.
     #[inline]
     pub fn combine(&mut self, other: Self) -> &mut Self {
-        if !other.modules.is_empty() {
         self.modules.extend(other.modules.into_iter());
-        }
-        if !other.variables.is_empty() {
         self.variables.extend(other.variables.into_iter());
-        }
-        if !other.functions.is_empty() {
         self.functions.extend(other.functions.into_iter());
-        }
-        if !other.type_iterators.is_empty() {
         self.type_iterators.extend(other.type_iterators.into_iter());
-        }
         self.all_functions.clear();
         self.all_variables.clear();
         self.indexed = false;
@@ -1148,20 +1140,38 @@ impl Module {
     /// Sub-modules are flattened onto the root module, with higher level overriding lower level.
     #[inline]
     pub fn combine_flatten(&mut self, other: Self) -> &mut Self {
-        if !other.modules.is_empty() {
         other.modules.into_iter().for_each(|(_, m)| {
             self.combine_flatten(m);
         });
-        }
-        if !other.variables.is_empty() {
         self.variables.extend(other.variables.into_iter());
-        }
-        if !other.functions.is_empty() {
         self.functions.extend(other.functions.into_iter());
-        }
-        if !other.type_iterators.is_empty() {
         self.type_iterators.extend(other.type_iterators.into_iter());
+        self.all_functions.clear();
+        self.all_variables.clear();
+        self.indexed = false;
+        self
     }
+
+    /// Poly-fill this module with another module.
+    /// Only items not existing in this module are added.
+    #[inline]
+    pub fn fill_with(&mut self, other: &Self) -> &mut Self {
+        other.modules.iter().for_each(|(k, v)| {
+            if !self.modules.contains_key(k) {
+                self.modules.insert(k.clone(), v.clone());
+            }
+        });
+        other.variables.iter().for_each(|(k, v)| {
+            if !self.variables.contains_key(k) {
+                self.variables.insert(k.clone(), v.clone());
+            }
+        });
+        other.functions.iter().for_each(|(&k, v)| {
+            self.functions.entry(k).or_insert_with(|| v.clone());
+        });
+        other.type_iterators.iter().for_each(|(&k, &v)| {
+            self.type_iterators.entry(k).or_insert(v);
+        });
         self.all_functions.clear();
         self.all_variables.clear();
         self.indexed = false;
@@ -1181,23 +1191,17 @@ impl Module {
         mut _filter: &mut impl FnMut(FnAccess, &str, usize) -> bool,
     ) -> &mut Self {
         #[cfg(not(feature = "no_function"))]
-        if !other.modules.is_empty() {
         other.modules.iter().for_each(|(k, v)| {
             let mut m = Self::new();
             m.merge_filtered(v, _filter);
             self.modules.insert(k.clone(), m);
         });
-        }
         #[cfg(feature = "no_function")]
-        if !other.modules.is_empty() {
         self.modules
             .extend(other.modules.iter().map(|(k, v)| (k.clone(), v.clone())));
-        }
+
-        if !other.variables.is_empty() {
         self.variables
             .extend(other.variables.iter().map(|(k, v)| (k.clone(), v.clone())));
-        }
-        if !other.functions.is_empty() {
         self.functions.extend(
             other
                 .functions
@@ -1211,12 +1215,8 @@ impl Module {
                 })
                 .map(|(&k, v)| (k, v.clone())),
         );
-        }
 
-        if !other.type_iterators.is_empty() {
+        self.type_iterators.extend(other.type_iterators.iter());
-            self.type_iterators
-                .extend(other.type_iterators.iter().map(|(&k, v)| (k, v.clone())));
-        }
         self.all_functions.clear();
         self.all_variables.clear();
         self.indexed = false;