Changing rules of operator overload lookup

core_typechecking.cpp

@@ -792,19 +792,20 @@ function void
 scope_search(Scope_Search *search){
   // Climb the scope tree and search each scope in module and also
   // search in implicitly imported scopes
-  Ast_Scope *scope = search->scope;
-  for(Ast_Scope *it = scope; it; it=it->parent_scope){
-    inside_scope_search(search, it, 0);
+  For_Named(search->scopes, scope){
+    for(Ast_Scope *it = scope; it; it=it->parent_scope){
+      inside_scope_search(search, it, 0);
 
-    if(search->exit_on_find && search->results.len){
-      return;
-    }
+      if(search->exit_on_find && search->results.len){
+        return;
+      }
 
-    if(search->search_only_current_scope){
-      return;
+      if(search->search_only_current_scope){
+        return;
+      }
     }
+    inside_scope_search(search, scope->module, 0);
   }
-  inside_scope_search(search, scope->module, 0);
 }
 
 function Scope_Search
@@ -813,7 +814,8 @@ make_scope_search(Arena *arena, Ast_Scope *scope, Intern_String name){
   result.results.allocator = arena;
   result.name = name;
   result.scope_visit_id = ++pctx->scope_visit_id;
-  result.scope = scope;
+  result.scopes = {arena};
+  result.scopes.add(scope);
   result.exit_on_find = true;
   return result;
 }
@@ -909,13 +911,16 @@ map_operator_intern_to_identifier_name(Intern_String op){
 }
 
 function Ast_Decl *
-resolve_operator_overload(Ast_Scope *scope, Token *pos, Token_Kind op, U64 argument_hash){
+resolve_operator_overload(Ast_Scope *scope, Ast_Type *left, Ast_Type *right, Token *pos, Token_Kind op, U64 argument_hash){
   Intern_String name = map_operator_to_intern(op);
   if(name.str == 0) return 0;
 
-  // Search for all possible candidates
+  // Search for all possible candidates in three scopes
+  // The current module, left type definition module, right type definition module
   Scratch scratch;
   Scope_Search search = make_scope_search(scratch, scope, name);
+  if(         left->ast  && left->ast->parent_scope)  search.scopes.add(left->ast->parent_scope);
+  if(right && right->ast && right->ast->parent_scope) search.scopes.add(right->ast->parent_scope);
   search.exit_on_find = false;
   scope_search(&search);
 
@@ -1639,7 +1644,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_context){
         // Try finding a operator overload
         if(!is_const){
           U64 hash = calculate_hash_for_arguments(left.type, right.type);
-          Ast_Decl *operator_overload = resolve_operator_overload(node->parent_scope, node->pos, node->op, hash);
+          Ast_Decl *operator_overload = resolve_operator_overload(node->parent_scope, left.type, right.type, node->pos, node->op, hash);
           if(operator_overload){
             proceed_to_default_operator_handler = false;
             if(operator_overload->lambda->ret.len != 1){
@@ -1706,7 +1711,7 @@ resolve_expr(Ast_Expr *ast, Resolve_Flag flags, Ast_Type *compound_context){
         B32 proceed_to_default_operator_handler = true;
         if(!value.is_const){
           U64 hash = calculate_hash_for_arguments(value.type);
-          Ast_Decl *operator_overload = resolve_operator_overload(node->parent_scope, node->pos, node->op, hash);
+          Ast_Decl *operator_overload = resolve_operator_overload(node->parent_scope, value.type, 0, node->pos, node->op, hash);
           if(operator_overload){
             proceed_to_default_operator_handler = false;
             if(operator_overload->lambda->ret.len != 1){

core_typechecking.h

@@ -10,7 +10,7 @@ struct Operand{
 struct Scope_Search {
   Array<Ast_Decl *> results;
   Intern_String name;
-  Ast_Scope *scope;
+  Array<Ast_Scope *> scopes;
 
   bool exit_on_find;
   bool search_only_current_scope;

examples/operator_overloading.kl

@@ -10,6 +10,8 @@ Vec3 :: struct;; x: F32; y: F32; z: F32
 main :: (): int
   a := Vec3{1,1,1}
   b := Vec3{2,3,4}
+
+  // The expressions are replaced with the defined lambdas
   c := a + b
   Assert(c.x == 3 && c.y == 4 && c.z == 5)
   d := -c