start sketching out type system

1 files changed, 92 insertions, 47 deletions

diff --git a/src/scope.c b/src/scope.c
index 367384a..fe35d58 100644
--- a/src/scope.c
+++ b/src/scope.c
@@ -29,6 +29,8 @@ struct scope *create_scope()
 
 	scope->number = counter++;
 	scope->symbols = visible_create(16); /* arbitrary number */
+	scope->traits = visible_create(1);
+	scope->types = visible_create(1);
 	return scope;
 }
 
@@ -43,6 +45,8 @@ void destroy_scope(struct scope *scope)
 	}
 
 	visible_destroy(&scope->symbols);
+	visible_destroy(&scope->traits);
+	visible_destroy(&scope->types);
 
 	struct scope *prev = scope->children, *cur;
 	if (prev)
@@ -54,17 +58,17 @@ void destroy_scope(struct scope *scope)
 	free(scope);
 }
 
-int scope_add_var(struct scope *scope, struct ast *var)
+int scope_add_symbol(struct scope *scope, struct ast *symbol)
 {
-	assert(var->k == AST_VAR_DEF);
-	struct ast **exists = visible_insert(&scope->symbols, var_id(var), var);
+	assert(symbol->k == AST_VAR_DEF || symbol->k == AST_PROC_DEF);
+	struct ast **exists = visible_insert(&scope->symbols, symbol->s, symbol);
 	if (!exists) {
-		internal_error("failed inserting var into scope");
+		internal_error("failed inserting symbol into scope");
 		return -1;
 	}
 
-	if (*exists != var) {
-		semantic_error(scope, var, "var redefined");
+	if (*exists != symbol) {
+		semantic_error(scope, symbol, "symbol redefined");
 		semantic_info(scope, *exists, "previously here");
 		return -1;
 	}
@@ -72,17 +76,38 @@ int scope_add_var(struct scope *scope, struct ast *var)
 	return 0;
 }
 
-int scope_add_proc(struct scope *scope, struct ast *proc)
+struct ast *scope_find_symbol(struct scope *scope, char *id)
+{
+	struct ast **v = visible_find(&scope->symbols, id);
+	if (!v)
+		return NULL;
+
+	return *v;
+}
+
+struct ast *file_scope_find_symbol(struct scope *scope, char *id)
+{
+	if (!scope)
+		return NULL;
+
+	struct ast *found = scope_find_symbol(scope, id);
+	if (found)
+		return found;
+
+	return file_scope_find_symbol(scope->parent, id);
+}
+
+int scope_add_type(struct scope *scope, struct ast *type)
 {
-	assert(proc->k == AST_PROC_DEF);
-	struct ast **exists = visible_insert(&scope->symbols, proc_id(proc), proc);
+	assert(type->k == AST_STRUCT_DEF);
+	struct ast **exists = visible_insert(&scope->symbols, type->s, type);
 	if (!exists) {
-		internal_error("failed inserting proc into scope");
+		internal_error("failed inserting type into scope");
 		return -1;
 	}
 
-	if (*exists != proc) {
-		semantic_error(scope, proc, "proc redefined");
+	if (*exists != type) {
+		semantic_error(scope, type, "type redefined");
 		semantic_info(scope, *exists, "previously here");
 		return -1;
 	}
@@ -90,79 +115,99 @@ int scope_add_proc(struct scope *scope, struct ast *proc)
 	return 0;
 }
 
-struct ast *scope_find_proc(struct scope *scope, char *id)
+int scope_add_chain(struct scope *scope, struct ast *type)
 {
-	struct ast **v = visible_find(&scope->symbols, id);
-	if (!v)
-		return NULL;
+	assert(type->k == AST_STRUCT_CONT);
+	struct ast *exists = file_scope_find_type(scope, type->s);
+	if (!exists) {
+		semantic_error(scope, type, "no previous definition");
+		return -1;
+	}
 
-	struct ast *n = *v;
-	assert(n);
+	assert(exists->k == AST_STRUCT_DEF || exists->k == AST_STRUCT_CONT);
+	if (ast_flags(exists, AST_FLAG_PUBLIC) || !ast_flags(type, AST_FLAG_PUBLIC)) {
+		type->chain = exists;
+		struct ast **v = visible_insert(&scope->types, type->s, type);
+		if (!v) {
+			internal_error("failed inserting type into chain");
+			return -1;
+		}
 
-	if (n->k != AST_PROC_DEF)
-		return NULL;
+		/* overwrite root */
+		if (*v != type)
+			*v = type;
 
-	return n;
-}
-
-struct ast *file_scope_find_proc(struct scope *scope, char *id)
-{
-	struct ast *n = file_scope_find_symbol(scope, id);
-	if (!n)
-		return NULL;
+		return 0;
+	}
 
-	if (n->k != AST_PROC_DEF)
-		return NULL;
+	struct ast *next = exists->chain;
+	while (next->k == AST_STRUCT_CONT && !ast_flags(next, AST_FLAG_PUBLIC)) {
+		exists = next;
+		next = next->chain;
+	}
 
-	return n;
+	exists->chain = type;
+	type->chain = exists;
+	return 0;
 }
 
-struct ast *scope_find_symbol(struct scope *scope, char *id)
+struct ast *scope_find_type(struct scope *scope, char *id)
 {
-	struct ast **v = visible_find(&scope->symbols, id);
+	struct ast **v = visible_find(&scope->types, id);
 	if (!v)
 		return NULL;
 
 	return *v;
 }
 
-struct ast *file_scope_find_symbol(struct scope *scope, char *id)
+struct ast *file_scope_find_type(struct scope *scope, char *id)
 {
 	if (!scope)
 		return NULL;
 
-	struct ast *found = scope_find_symbol(scope, id);
+	struct ast *found = scope_find_type(scope, id);
 	if (found)
 		return found;
 
-	return file_scope_find_symbol(scope->parent, id);
+	return file_scope_find_type(scope->parent, id);
 }
 
-struct ast *scope_find_var(struct scope *scope, char *id)
+int scope_add_trait(struct scope *scope, struct ast *trait)
 {
-	struct ast **v = visible_find(&scope->symbols, id);
-	if (!v)
-		return NULL;
+	assert(trait->k == AST_TRAIT_DEF);
+	struct ast **exists = visible_insert(&scope->symbols, trait->s, trait);
+	if (!exists) {
+		internal_error("failed inserting trait into scope");
+		return -1;
+	}
 
-	struct ast *n = *v;
-	assert(n);
+	if (*exists != trait) {
+		semantic_error(scope, trait, "trait redefined");
+		semantic_info(scope, *exists, "previously here");
+		return -1;
+	}
 
-	if (n->k != AST_VAR_DEF)
+	return 0;
+}
+struct ast *scope_find_trait(struct scope *scope, char *id)
+{
+	struct ast **v = visible_find(&scope->traits, id);
+	if (!v)
 		return NULL;
 
-	return n;
+	return *v;
 }
 
-struct ast *file_scope_find_var(struct scope *scope, char *id)
+struct ast *file_scope_find_trait(struct scope *scope, char *id)
 {
 	if (!scope)
 		return NULL;
 
-	struct ast *found = scope_find_var(scope, id);
+	struct ast *found = scope_find_trait(scope, id);
 	if (found)
 		return found;
 
-	return file_scope_find_var(scope->parent, id);
+	return file_scope_find_trait(scope->parent, id);
 }
 
 void scope_add_scope(struct scope *parent, struct scope *child)