Code use API rather than raw CheckerInfo; begin work on generic procedures

7 files changed, 280 insertions, 129 deletions

diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index e2f0c45a3..2673a4d17 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -312,6 +312,8 @@ void check_proc_decl(Checker *c, Entity *e, DeclInfo *d) {
 	ast_node(pd, ProcDecl, d->proc_decl);
 
 	check_open_scope(c, pd->type);
+	defer (check_close_scope(c));
+
 	check_procedure_type(c, proc_type, pd->type);
 
 	bool is_foreign         = (pd->tags & ProcTag_foreign)   != 0;
@@ -322,15 +324,14 @@ void check_proc_decl(Checker *c, Entity *e, DeclInfo *d) {
 	bool is_require_results = (pd->tags & ProcTag_require_results) != 0;
 
 
+	TypeProc *pt = &proc_type->Proc;
+
 	if (d->scope->is_file && e->token.string == "main") {
-		if (proc_type != NULL) {
-			TypeProc *pt = &proc_type->Proc;
-			if (pt->param_count != 0 ||
-			    pt->result_count != 0) {
-				gbString str = type_to_string(proc_type);
-				error(e->token, "Procedure type of `main` was expected to be `proc()`, got %s", str);
-				gb_string_free(str);
-			}
+		if (pt->param_count != 0 ||
+		    pt->result_count != 0) {
+			gbString str = type_to_string(proc_type);
+			error(e->token, "Procedure type of `main` was expected to be `proc()`, got %s", str);
+			gb_string_free(str);
 		}
 	}
 
@@ -343,6 +344,12 @@ void check_proc_decl(Checker *c, Entity *e, DeclInfo *d) {
 	}
 
 
+	if (pt->is_generic) {
+		if (pd->body == NULL) {
+			error(e->token, "Generic procedures must have a body");
+		}
+	}
+
 	if (pd->body != NULL) {
 		if (is_foreign) {
 			error_node(pd->body, "A foreign procedure cannot have a body");
@@ -357,14 +364,10 @@ void check_proc_decl(Checker *c, Entity *e, DeclInfo *d) {
 		check_procedure_later(c, c->curr_ast_file, e->token, d, proc_type, pd->body, pd->tags);
 	}
 
-
-	if (proc_type != NULL && is_type_proc(proc_type)) {
-		TypeProc *tp = &proc_type->Proc;
-		if (tp->result_count == 0 && is_require_results) {
-			error_node(pd->type, "`#require_results` is not needed on a procedure with no results");
-		} else {
-			tp->require_results = is_require_results;
-		}
+	if (pt->result_count == 0 && is_require_results) {
+		error_node(pd->type, "`#require_results` is not needed on a procedure with no results");
+	} else {
+		pt->require_results = is_require_results;
 	}
 
 	if (is_foreign) {
@@ -428,8 +431,6 @@ void check_proc_decl(Checker *c, Entity *e, DeclInfo *d) {
 			}
 		}
 	}
-
-	check_close_scope(c);
 }
 
 void check_var_decl(Checker *c, Entity *e, Entity **entities, isize entity_count, AstNode *type_expr, AstNode *init_expr) {
@@ -506,10 +507,8 @@ void check_entity_decl(Checker *c, Entity *e, DeclInfo *d, Type *named_type) {
 	}
 
 	if (d == NULL) {
-		DeclInfo **found = map_get(&c->info.entities, hash_pointer(e));
-		if (found) {
-			d = *found;
-		} else {
+		d = decl_info_of_entity(&c->info, e);
+		if (d == NULL) {
 			// TODO(bill): Err here?
 			e->type = t_invalid;
 			set_base_type(named_type, t_invalid);
@@ -577,10 +576,10 @@ void check_proc_body(Checker *c, Token token, DeclInfo *decl, Type *type, AstNod
 			String name = e->token.string;
 			Type *t = base_type(type_deref(e->type));
 			if (is_type_struct(t) || is_type_raw_union(t)) {
-				Scope **found = map_get(&c->info.scopes, hash_pointer(t->Record.node));
-				GB_ASSERT(found != NULL);
-				for_array(i, (*found)->elements.entries) {
-					Entity *f = (*found)->elements.entries[i].value;
+				Scope *scope = scope_of_node(&c->info, t->Record.node);
+				GB_ASSERT(scope != NULL);
+				for_array(i, scope->elements.entries) {
+					Entity *f = scope->elements.entries[i].value;
 					if (f->kind == Entity_Variable) {
 						Entity *uvar = make_entity_using_variable(c->allocator, e, f->token, f->type);
 						uvar->Variable.is_immutable = is_immutable;
diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 8fdec8e53..6a391f00c 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -57,9 +57,8 @@ void check_scope_decls(Checker *c, Array<AstNode *> nodes, isize reserve_size) {
 		default:
 			continue;
 		}
-		DeclInfo **found = map_get(&c->info.entities, hash_pointer(e));
-		if (found != NULL) {
-			DeclInfo *d = *found;
+		DeclInfo *d = decl_info_of_entity(&c->info, e);
+		if (d != NULL) {
 			check_entity_decl(c, e, d, NULL);
 		}
 	}
@@ -1069,7 +1068,7 @@ Type *check_get_params(Checker *c, Scope *scope, AstNode *_params, bool *is_vari
 
 		if (type_expr == NULL) {
 			Operand o = {};
-			check_expr(c, &o, default_value);
+			check_expr_or_type(c, &o, default_value);
 			if (is_operand_nil(o)) {
 				default_is_nil = true;
 			} else if (o.mode != Addressing_Constant) {
@@ -1088,8 +1087,11 @@ Type *check_get_params(Checker *c, Scope *scope, AstNode *_params, bool *is_vari
 					error_node(param, "Invalid AST: Invalid variadic parameter");
 				}
 			}
-
-			type = check_type(c, type_expr);
+			if (type_expr->kind == AstNode_HelperType) {
+				type = make_type_generic(c->allocator, 0);
+			} else {
+				type = check_type(c, type_expr);
+			}
 
 			if (default_value != NULL) {
 				Operand o = {};
@@ -1135,13 +1137,18 @@ Type *check_get_params(Checker *c, Scope *scope, AstNode *_params, bool *is_vari
 		for_array(j, p->names) {
 			AstNode *name = p->names[j];
 			if (ast_node_expect(name, AstNode_Ident)) {
-				Entity *param = make_entity_param(c->allocator, scope, name->Ident, type,
-				                                  (p->flags&FieldFlag_using) != 0, false);
+				Entity *param = NULL;
+				if (type->kind == Type_Generic) {
+					param = make_entity_type_name(c->allocator, scope, name->Ident, type);
+				} else {
+					param = make_entity_param(c->allocator, scope, name->Ident, type,
+					                          (p->flags&FieldFlag_using) != 0, false);
+					param->Variable.default_value = value;
+					param->Variable.default_is_nil = default_is_nil;
+				}
 				if (p->flags&FieldFlag_no_alias) {
 					param->flags |= EntityFlag_NoAlias;
 				}
-				param->Variable.default_value = value;
-				param->Variable.default_is_nil = default_is_nil;
 
 				add_entity(c, scope, name, param);
 				variables[variable_index++] = param;
@@ -1436,6 +1443,15 @@ void check_procedure_type(Checker *c, Type *type, AstNode *proc_type_node) {
 				type->Proc.c_vararg = true;
 			}
 		}
+
+		bool is_generic = false;
+		for (isize i = 0; i < param_count; i++) {
+			Entity *e = params->Tuple.variables[i];
+			if (e->type->kind == Type_Generic) {
+				is_generic = true;
+			}
+		}
+		type->Proc.is_generic = is_generic;
 	}
 
 
@@ -1593,7 +1609,7 @@ Entity *check_ident(Checker *c, Operand *o, AstNode *n, Type *named_type, Type *
 		}
 		return e;
 	case Entity_LibraryName:
-		error_node(n, "Use of library `%.*s` not in #foreign tag", LIT(name));
+		error_node(n, "Use of library `%.*s` not in foreign block", LIT(name));
 		return e;
 
 	case Entity_Label:
@@ -1844,11 +1860,6 @@ bool check_type_internal(Checker *c, AstNode *e, Type **type, Type *named_type)
 		} */
 	case_end;
 
-	case_ast_node(ht, HelperType, e);
-		*type = check_type(c, ht->type);
-		return true;
-	case_end;
-
 	case_ast_node(pt, PointerType, e);
 		Type *elem = check_type(c, pt->type);
 		i64 esz = type_size_of(c->allocator, elem);
@@ -2559,7 +2570,7 @@ void check_shift(Checker *c, Operand *x, Operand *y, AstNode *node) {
 
 		TokenPos pos = ast_node_token(x->expr).pos;
 		if (x_is_untyped) {
-			ExprInfo *info = map_get(&c->info.untyped, hash_pointer(x->expr));
+			ExprInfo *info = check_get_expr_info(&c->info, x->expr);
 			if (info != NULL) {
 				info->is_lhs = true;
 			}
@@ -3014,8 +3025,7 @@ void check_binary_expr(Checker *c, Operand *x, AstNode *node) {
 
 
 void update_expr_type(Checker *c, AstNode *e, Type *type, bool final) {
-	HashKey key = hash_pointer(e);
-	ExprInfo *found = map_get(&c->info.untyped, key);
+	ExprInfo *found = check_get_expr_info(&c->info, e);
 	if (found == NULL) {
 		return;
 	}
@@ -3054,12 +3064,12 @@ void update_expr_type(Checker *c, AstNode *e, Type *type, bool final) {
 
 	if (!final && is_type_untyped(type)) {
 		old.type = base_type(type);
-		map_set(&c->info.untyped, key, old);
+		check_set_expr_info(&c->info, e, old);
 		return;
 	}
 
 	// We need to remove it and then give it a new one
-	map_remove(&c->info.untyped, key);
+	check_remove_expr_info(&c->info, e);
 
 	if (old.is_lhs && !is_type_integer(type)) {
 		gbString expr_str = expr_to_string(e);
@@ -3074,7 +3084,7 @@ void update_expr_type(Checker *c, AstNode *e, Type *type, bool final) {
 }
 
 void update_expr_value(Checker *c, AstNode *e, ExactValue value) {
-	ExprInfo *found = map_get(&c->info.untyped, hash_pointer(e));
+	ExprInfo *found = check_get_expr_info(&c->info, e);
 	if (found) {
 		found->value = value;
 	}
@@ -4741,7 +4751,13 @@ bool check_unpack_arguments(Checker *c, isize lhs_count, Array<Operand> *operand
 	bool optional_ok = false;
 	for_array(i, rhs) {
 		Operand o = {};
-		check_multi_expr(c, &o, rhs[i]);
+		check_expr_base(c, &o, rhs[i], NULL);
+		if (o.mode == Addressing_NoValue) {
+			error_operand_no_value(&o);
+			o.mode = Addressing_Invalid;
+		}
+		// check_multi_expr(c, &o, rhs[i]);
+
 
 		if (o.type == NULL || o.type->kind != Type_Tuple) {
 			if (allow_ok && lhs_count == 2 && rhs.count == 1 &&
@@ -4801,6 +4817,10 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 	if (param_tuple != NULL) {
 		for (isize i = param_count-1; i >= 0; i--) {
 			Entity *e = param_tuple->variables[i];
+			if (e->kind == Entity_TypeName) {
+				break;
+			}
+
 			GB_ASSERT(e->kind == Entity_Variable);
 			if (e->Variable.default_value.kind != ExactValue_Invalid) {
 				param_count_excluding_defaults--;
@@ -4863,13 +4883,25 @@ CALL_ARGUMENT_CHECKER(check_call_arguments_internal) {
 
 	CallArgumentError err = CallArgumentError_None;
 
+
 	GB_ASSERT(proc_type->Proc.params != NULL);
 	Entity **sig_params = param_tuple->variables;
 	isize operand_index = 0;
 	isize max_operand_count = gb_min(param_count, operands.count);
 	for (; operand_index < max_operand_count; operand_index++) {
-		Type *t = sig_params[operand_index]->type;
+		Entity *e = sig_params[operand_index];
+		Type *t = e->type;
 		Operand o = operands[operand_index];
+		if (e->kind == Entity_TypeName) {
+			GB_ASSERT(proc_type->Proc.is_generic);
+			GB_ASSERT(!variadic);
+			if (o.mode == Addressing_Invalid) {
+				continue;
+			} else if (o.mode != Addressing_Type) {
+				error_node(o.expr, "Expected a type for the argument");
+			}
+			continue;
+		}
 		if (variadic) {
 			o = operands[operand_index];
 		}
@@ -4984,17 +5016,27 @@ CALL_ARGUMENT_CHECKER(check_named_call_arguments) {
 
 		params_visited[index] = true;
 		Operand *o = &operands[i];
+		Entity *e = pt->params->Tuple.variables[index];
 
-		Type *param_type = pt->params->Tuple.variables[index]->type;
-
-		i64 s = 0;
-		if (!check_is_assignable_to_with_score(c, o, param_type, &s)) {
-			if (show_error) {
-				check_assignment(c, o, param_type, str_lit("procedure argument"));
+		if (e->kind == Entity_TypeName) {
+			GB_ASSERT(pt->is_generic);
+			GB_ASSERT(!pt->variadic);
+			if (o->mode == Addressing_Invalid) {
+				continue;
+			} else if (o->mode != Addressing_Type) {
+				error_node(o->expr, "Expected a type for the argument");
 			}
-			err = CallArgumentError_WrongTypes;
+			score += 1;
+		} else {
+			i64 s = 0;
+			if (!check_is_assignable_to_with_score(c, o, e->type, &s)) {
+				if (show_error) {
+					check_assignment(c, o, e->type, str_lit("procedure argument"));
+				}
+				err = CallArgumentError_WrongTypes;
+			}
+			score += s;
 		}
-		score += s;
 	}
 
 
@@ -5079,9 +5121,8 @@ Type *check_call_arguments(Checker *c, Operand *operand, Type *proc_type, AstNod
 
 		for (isize i = 0; i < overload_count; i++) {
 			Entity *e = procs[i];
-			DeclInfo **found = map_get(&c->info.entities, hash_pointer(e));
-			GB_ASSERT(found != NULL);
-			DeclInfo *d = *found;
+			DeclInfo *d = decl_info_of_entity(&c->info, e);
+			GB_ASSERT(d != NULL);
 			check_entity_decl(c, e, d, NULL);
 		}
 
@@ -5277,18 +5318,27 @@ ExprKind check_call_expr(Checker *c, Operand *operand, AstNode *call) {
 		operand->expr = call;
 		return Expr_Stmt;
 	}
-	switch (pt->Proc.result_count) {
-	case 0:
+
+	bool results_are_generic = false;
+	if (pt->Proc.results != NULL) {
+		results_are_generic = is_type_generic(pt->Proc.results);
+	}
+	if (results_are_generic) {
 		operand->mode = Addressing_NoValue;
-		break;
-	case 1:
-		operand->mode = Addressing_Value;
-		operand->type = pt->Proc.results->Tuple.variables[0]->type;
-		break;
-	default:
-		operand->mode = Addressing_Value;
-		operand->type = pt->Proc.results;
-		break;
+	} else {
+		switch (pt->Proc.result_count) {
+		case 0:
+			operand->mode = Addressing_NoValue;
+			break;
+		case 1:
+			operand->mode = Addressing_Value;
+			operand->type = pt->Proc.results->Tuple.variables[0]->type;
+			break;
+		default:
+			operand->mode = Addressing_Value;
+			operand->type = pt->Proc.results;
+			break;
+		}
 	}
 
 	operand->expr = call;
@@ -6628,11 +6678,6 @@ gbString write_expr_to_string(gbString str, AstNode *node) {
 		str = gb_string_appendc(str, "}");
 	case_end;
 
-	case_ast_node(ht, HelperType, node);
-		str = gb_string_appendc(str, "#type ");
-		str = write_expr_to_string(str, ht->type);
-	case_end;
-
 	case_ast_node(at, AtomicType, node);
 		str = gb_string_appendc(str, "atomic ");
 		str = write_expr_to_string(str, at->type);
diff --git a/src/check_stmt.cpp b/src/check_stmt.cpp
index 8b1590e59..fbf301878 100644
--- a/src/check_stmt.cpp
+++ b/src/check_stmt.cpp
@@ -530,9 +530,7 @@ bool check_using_stmt_entity(Checker *c, AstNodeUsingStmt *us, AstNode *expr, bo
 		Type *t = base_type(type_deref(e->type));
 		if (is_type_struct(t) || is_type_raw_union(t) || is_type_union(t)) {
 			// TODO(bill): Make it work for unions too
-			Scope **found_ = map_get(&c->info.scopes, hash_pointer(t->Record.node));
-			GB_ASSERT(found_ != NULL);
-			Scope *found = *found_;
+			Scope *found = scope_of_node(&c->info, t->Record.node);
 			for_array(i, found->elements.entries) {
 				Entity *f = found->elements.entries[i].value;
 				if (f->kind == Entity_Variable) {
@@ -1695,10 +1693,9 @@ void check_stmt_internal(Checker *c, AstNode *node, u32 flags) {
 						Type *t = base_type(type_deref(e->type));
 
 						if (is_type_struct(t) || is_type_raw_union(t)) {
-							Scope **found = map_get(&c->info.scopes, hash_pointer(t->Record.node));
-							GB_ASSERT(found != NULL);
-							for_array(i, (*found)->elements.entries) {
-								Entity *f = (*found)->elements.entries[i].value;
+							Scope *scope = scope_of_node(&c->info, t->Record.node);
+							for_array(i, scope->elements.entries) {
+								Entity *f = scope->elements.entries[i].value;
 								if (f->kind == Entity_Variable) {
 									Entity *uvar = make_entity_using_variable(c->allocator, e, f->token, f->type);
 									uvar->Variable.is_immutable = is_immutable;
diff --git a/src/checker.cpp b/src/checker.cpp
index 3dabbb694..7fc849237 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -284,7 +284,8 @@ struct Checker {
 
 	AstFile *              curr_ast_file;
 	Scope *                global_scope;
-	Array<ProcedureInfo>   procs; // NOTE(bill): Procedures to check
+	// NOTE(bill): Procedures to check
+	Map<ProcedureInfo>     procs; // Key: DeclInfo *
 	Array<DelayedDecl>     delayed_imports;
 	Array<DelayedDecl>     delayed_foreign_libraries;
 	Array<CheckerFileNode> file_nodes;
@@ -307,6 +308,22 @@ struct DelayedEntity {
 	DeclInfo *  decl;
 };
 
+Entity *     entity_of_ident        (CheckerInfo *i, AstNode *identifier);
+TypeAndValue type_and_value_of_expr (CheckerInfo *i, AstNode *expr);
+Type *       type_of_expr           (CheckerInfo *i, AstNode *expr);
+Entity *     implicit_entity_of_node(CheckerInfo *i, AstNode *clause);
+DeclInfo *   decl_info_of_entity    (CheckerInfo *i, Entity * e);
+DeclInfo *   decl_info_of_ident     (CheckerInfo *i, AstNode *ident);
+AstFile *    ast_file_of_filename   (CheckerInfo *i, String   filename);
+Scope *      scope_of_node          (CheckerInfo *i, AstNode *node);
+ExprInfo *   check_get_expr_info    (CheckerInfo *i, AstNode *expr);
+void         check_set_expr_info    (CheckerInfo *i, AstNode *expr, ExprInfo info);
+void         check_remove_expr_info (CheckerInfo *i, AstNode *expr);
+
+Entity *current_scope_lookup_entity(Scope *s, String name);
+void    scope_lookup_parent_entity (Scope *s, String name, Scope **scope_, Entity **entity_);
+Entity *scope_lookup_entity        (Scope *s, String name);
+Entity *scope_insert_entity        (Scope *s, Entity *entity);
 
 
 
@@ -596,11 +613,12 @@ void add_global_constant(gbAllocator a, String name, Type *type, ExactValue valu
 
 void add_global_string_constant(gbAllocator a, String name, String value) {
 	add_global_constant(a, name, t_untyped_string, exact_value_string(value));
-
 }
 
 
 
+
+
 void init_universal_scope(void) {
 	BuildContext *bc = &build_context;
 	// NOTE(bill): No need to free these
@@ -701,7 +719,7 @@ void init_checker(Checker *c, Parser *parser, BuildContext *bc) {
 	init_checker_info(&c->info);
 
 	array_init(&c->proc_stack, a);
-	array_init(&c->procs, a);
+	map_init(&c->procs, a);
 	array_init(&c->delayed_imports, a);
 	array_init(&c->delayed_foreign_libraries, a);
 	array_init(&c->file_nodes, a);
@@ -738,7 +756,7 @@ void destroy_checker(Checker *c) {
 	destroy_checker_info(&c->info);
 	destroy_scope(c->global_scope);
 	array_free(&c->proc_stack);
-	array_free(&c->procs);
+	map_destroy(&c->procs);
 	array_free(&c->delayed_imports);
 	array_free(&c->delayed_foreign_libraries);
 	array_free(&c->file_nodes);
@@ -761,9 +779,9 @@ Entity *entity_of_ident(CheckerInfo *i, AstNode *identifier) {
 	return NULL;
 }
 
-TypeAndValue type_and_value_of_expr(CheckerInfo *i, AstNode *expression) {
+TypeAndValue type_and_value_of_expr(CheckerInfo *i, AstNode *expr) {
 	TypeAndValue result = {};
-	TypeAndValue *found = map_get(&i->types, hash_pointer(expression));
+	TypeAndValue *found = map_get(&i->types, hash_pointer(expr));
 	if (found) result = *found;
 	return result;
 }
@@ -812,8 +830,22 @@ AstFile *ast_file_of_filename(CheckerInfo *i, String filename) {
 	}
 	return NULL;
 }
-
-
+Scope *scope_of_node(CheckerInfo *i, AstNode *node) {
+	Scope **found = map_get(&i->scopes, hash_pointer(node));
+	if (found) {
+		return *found;
+	}
+	return NULL;
+}
+ExprInfo *check_get_expr_info(CheckerInfo *i, AstNode *expr) {
+	return map_get(&i->untyped, hash_pointer(expr));
+}
+void check_set_expr_info(CheckerInfo *i, AstNode *expr, ExprInfo info) {
+	map_set(&i->untyped, hash_pointer(expr), info);
+}
+void check_remove_expr_info(CheckerInfo *i, AstNode *expr) {
+	map_remove(&i->untyped, hash_pointer(expr));
+}
 
 
 
@@ -1082,7 +1114,7 @@ void check_procedure_later(Checker *c, AstFile *file, Token token, DeclInfo *dec
 	info.type  = type;
 	info.body  = body;
 	info.tags  = tags;
-	array_add(&c->procs, info);
+	map_set(&c->procs, hash_pointer(decl), info);
 }
 
 void push_procedure(Checker *c, Type *type) {
@@ -1113,24 +1145,21 @@ void add_curr_ast_file(Checker *c, AstFile *file) {
 }
 
 
-
-
-void add_dependency_to_map(Map<Entity *> *map, CheckerInfo *info, Entity *node) {
-	if (node == NULL) {
+void add_dependency_to_map(Map<Entity *> *map, CheckerInfo *info, Entity *entity) {
+	if (entity == NULL) {
 		return;
 	}
-	if (map_get(map, hash_pointer(node)) != NULL) {
+	if (map_get(map, hash_pointer(entity)) != NULL) {
 		return;
 	}
-	map_set(map, hash_pointer(node), node);
+	map_set(map, hash_pointer(entity), entity);
 
 
-	DeclInfo **found = map_get(&info->entities, hash_pointer(node));
-	if (found == NULL) {
+	DeclInfo *decl = decl_info_of_entity(info, entity);
+	if (decl == NULL) {
 		return;
 	}
 
-	DeclInfo *decl = *found;
 	for_array(i, decl->deps.entries) {
 		Entity *e = cast(Entity *)decl->deps.entries[i].key.ptr;
 		add_dependency_to_map(map, info, e);
@@ -1333,6 +1362,15 @@ void check_procedure_overloading(Checker *c, Entity *e) {
 
 			TokenPos pos = q->token.pos;
 
+			if (is_type_proc(q->type)) {
+				TypeProc *ptq = &base_type(q->type)->Proc;
+				if (ptq->is_generic) {
+					q->type = t_invalid;
+					error(q->token, "Generic procedure `%.*s` cannot be overloaded", LIT(name));
+					continue;
+				}
+			}
+
 			ProcTypeOverloadKind kind = are_proc_types_overload_safe(p->type, q->type);
 			switch (kind) {
 			case ProcOverload_Identical:
@@ -2132,9 +2170,17 @@ void check_parsed_files(Checker *c) {
 
 	// Check procedure bodies
 	// NOTE(bill): Nested procedures bodies will be added to this "queue"
-	for_array(i, c->procs) {
-		ProcedureInfo *pi = &c->procs[i];
+	for_array(i, c->procs.entries) {
+		ProcedureInfo *pi = &c->procs.entries[i].value;
 		CheckerContext prev_context = c->context;
+		defer (c->context = prev_context);
+
+		TypeProc *pt = &pi->type->Proc;
+		if (pt->is_generic) {
+			error(pi->token, "Generic procedures are not yet supported");
+			continue;
+		}
+
 		add_curr_ast_file(c, pi->file);
 
 		bool bounds_check    = (pi->tags & ProcTag_bounds_check)    != 0;
@@ -2150,8 +2196,6 @@ void check_parsed_files(Checker *c) {
 		}
 
 		check_proc_body(c, pi->token, pi->decl, pi->type, pi->body);
-
-		c->context = prev_context;
 	}
 
 	// Add untyped expression values
diff --git a/src/ir.cpp b/src/ir.cpp
index b9f07c166..75f9b8153 100644
--- a/src/ir.cpp
+++ b/src/ir.cpp
@@ -1134,10 +1134,7 @@ irValue *ir_generate_array(irModule *m, Type *elem_type, i64 count, String prefi
 irBlock *ir_new_block(irProcedure *proc, AstNode *node, char *label) {
 	Scope *scope = NULL;
 	if (node != NULL) {
-		Scope **found = map_get(&proc->module->info->scopes, hash_pointer(node));
-		if (found) {
-			scope = *found;
-		}
+		scope = scope_of_node(proc->module->info, node);
 		GB_ASSERT_MSG(scope != NULL, "Block scope not found for %.*s", LIT(ast_node_strings[node->kind]));
 	}
 
diff --git a/src/parser.cpp b/src/parser.cpp
index 4f0595d78..8aadba765 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -363,7 +363,6 @@ AST_NODE_KIND(_DeclEnd,   "", i32) \
 AST_NODE_KIND(_TypeBegin, "", i32) \
 	AST_NODE_KIND(HelperType, "type", struct { \
 		Token token; \
-		AstNode *type; \
 	}) \
 	AST_NODE_KIND(ProcType, "procedure type", struct { \
 		Token    token;   \
@@ -790,7 +789,6 @@ AstNode *clone_ast_node(gbAllocator a, AstNode *node) {
 		break;
 
 	case AstNode_HelperType:
-		n->HelperType.type = clone_ast_node(a, n->HelperType.type);
 		break;
 	case AstNode_ProcType:
 		break;
@@ -1313,10 +1311,9 @@ AstNode *ast_union_field(AstFile *f, AstNode *name, AstNode *list) {
 }
 
 
-AstNode *ast_helper_type(AstFile *f, Token token, AstNode *type) {
+AstNode *ast_helper_type(AstFile *f, Token token) {
 	AstNode *result = make_ast_node(f, AstNode_HelperType);
 	result->HelperType.token = token;
-	result->HelperType.type = type;
 	return result;
 }
 
@@ -1684,9 +1681,6 @@ bool is_semicolon_optional_for_node(AstFile *f, AstNode *s) {
 	case AstNode_TypeMatchStmt:
 		return true;
 
-	case AstNode_HelperType:
-		return is_semicolon_optional_for_node(f, s->HelperType.type);
-
 	case AstNode_PointerType:
 		return is_semicolon_optional_for_node(f, s->PointerType.type);
 
@@ -2108,11 +2102,6 @@ AstNode *parse_operand(AstFile *f, bool lhs) {
 		return ast_paren_expr(f, operand, open, close);
 	}
 
-	case Token_type: {
-		Token token = expect_token(f, Token_type);
-		return ast_helper_type(f, token, parse_type(f));
-	}
-
 	case Token_Hash: {
 		Token token = expect_token(f, Token_Hash);
 		Token name  = expect_token(f, Token_Ident);
@@ -3057,7 +3046,7 @@ AstNode *parse_proc_type(AstFile *f, Token proc_token, String *link_name_) {
 	return ast_proc_type(f, proc_token, params, results, tags, cc);
 }
 
-AstNode *parse_var_type(AstFile *f, bool allow_ellipsis) {
+AstNode *parse_var_type(AstFile *f, bool allow_ellipsis, bool allow_type_token) {
 	if (allow_ellipsis && f->curr_token.kind == Token_Ellipsis) {
 		Token tok = f->curr_token;
 		next_token(f);
@@ -3068,7 +3057,13 @@ AstNode *parse_var_type(AstFile *f, bool allow_ellipsis) {
 		}
 		return ast_ellipsis(f, tok, type);
 	}
-	AstNode *type = parse_type_attempt(f);
+	AstNode *type = NULL;
+	if (allow_type_token &&
+	    f->curr_token.kind == Token_type) {
+		type = ast_helper_type(f, expect_token(f, Token_type));
+	} else {
+		type = parse_type_attempt(f);
+	}
 	if (type == NULL) {
 		Token tok = f->curr_token;
 		error(tok, "Expected a type");
@@ -3221,7 +3216,7 @@ AstNode *parse_field_list(AstFile *f, isize *name_count_, u32 allowed_flags, Tok
 	       f->curr_token.kind != Token_Colon &&
 	       f->curr_token.kind != Token_EOF) {
 		u32 flags = parse_field_prefixes(f);
-		AstNode *param = parse_var_type(f, allow_ellipsis);
+		AstNode *param = parse_var_type(f, allow_ellipsis, is_procedure);
 		AstNodeAndFlags naf = {param, flags};
 		array_add(&list, naf);
 		if (f->curr_token.kind != Token_Comma) {
@@ -3248,7 +3243,7 @@ AstNode *parse_field_list(AstFile *f, isize *name_count_, u32 allowed_flags, Tok
 
 		if (f->curr_token.kind != Token_Eq) {
 			expect_token_after(f, Token_Colon, "field list");
-			type = parse_var_type(f, allow_ellipsis);
+			type = parse_var_type(f, allow_ellipsis, is_procedure);
 		}
 		if (allow_token(f, Token_Eq)) {
 			// TODO(bill): Should this be true==lhs or false==rhs?
@@ -3282,7 +3277,7 @@ AstNode *parse_field_list(AstFile *f, isize *name_count_, u32 allowed_flags, Tok
 			AstNode *default_value = NULL;
 			if (f->curr_token.kind != Token_Eq) {
 				expect_token_after(f, Token_Colon, "field list");
-				type = parse_var_type(f, allow_ellipsis);
+				type = parse_var_type(f, allow_ellipsis, is_procedure);
 			}
 			if (allow_token(f, Token_Eq)) {
 				// TODO(bill): Should this be true==lhs or false==rhs?
@@ -3482,7 +3477,7 @@ AstNode *parse_type_or_ident(AstFile *f) {
 				u32 set_flags = check_field_prefixes(f, names.count, FieldFlag_using, decl_flags);
 				total_decl_name_count += names.count;
 				expect_token_after(f, Token_Colon, "field list");
-				AstNode *type = parse_var_type(f, false);
+				AstNode *type = parse_var_type(f, false, false);
 				array_add(&decls, ast_field(f, names, type, NULL, set_flags));
 			} else {
 				Array<AstNode *> names = parse_ident_list(f);
@@ -3493,7 +3488,7 @@ AstNode *parse_type_or_ident(AstFile *f) {
 					u32 set_flags = check_field_prefixes(f, names.count, FieldFlag_using, decl_flags);
 					total_decl_name_count += names.count;
 					expect_token_after(f, Token_Colon, "field list");
-					AstNode *type = parse_var_type(f, false);
+					AstNode *type = parse_var_type(f, false, false);
 					array_add(&decls, ast_field(f, names, type, NULL, set_flags));
 				} else {
 					AstNode *name  = names[0];
diff --git a/src/types.cpp b/src/types.cpp
index 4b1f276c0..94d4cf7c8 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -115,6 +115,7 @@ struct TypeRecord {
 
 #define TYPE_KINDS                                        \
 	TYPE_KIND(Basic,   BasicType)                         \
+	TYPE_KIND(Generic, struct{ i64 id; })                 \
 	TYPE_KIND(Pointer, struct { Type *elem; })            \
 	TYPE_KIND(Atomic,  struct { Type *elem; })            \
 	TYPE_KIND(Array,   struct { Type *elem; i64 count; }) \
@@ -145,6 +146,7 @@ struct TypeRecord {
 		bool   variadic;                                  \
 		bool   require_results;                           \
 		bool   c_vararg;                                  \
+		bool   is_generic;                                \
 		ProcCallingConvention calling_convention;         \
 	})                                                    \
 	TYPE_KIND(Map, struct {                               \
@@ -467,6 +469,12 @@ Type *make_type_basic(gbAllocator a, BasicType basic) {
 	return t;
 }
 
+Type *make_type_generic(gbAllocator a, i64 id) {
+	Type *t = alloc_type(a, Type_Generic);
+	t->Generic.id = id;
+	return t;
+}
+
 Type *make_type_pointer(gbAllocator a, Type *elem) {
 	Type *t = alloc_type(a, Type_Pointer);
 	t->Pointer.elem = elem;
@@ -917,6 +925,72 @@ bool is_type_indexable(Type *t) {
 	return is_type_array(t) || is_type_slice(t) || is_type_vector(t) || is_type_string(t);
 }
 
+bool is_type_generic(Type *t) {
+	t = core_type(t);
+	switch (t->kind) {
+	case Type_Generic:
+		return true;
+
+	case Type_Pointer:
+		return is_type_generic(t->Pointer.elem);
+	case Type_Atomic:
+		return is_type_generic(t->Atomic.elem);
+	case Type_Array:
+		return is_type_generic(t->Array.elem);
+	case Type_DynamicArray:
+		return is_type_generic(t->DynamicArray.elem);
+	case Type_Vector:
+		return is_type_generic(t->Vector.elem);
+	case Type_Slice:
+		return is_type_generic(t->Slice.elem);
+
+	case Type_Tuple:
+		for (isize i = 0; i < t->Tuple.variable_count; i++) {
+			if (is_type_generic(t->Tuple.variables[i]->type)) {
+				return true;
+			}
+		}
+		break;
+
+	case Type_Proc:
+		if (t->Proc.param_count > 0 &&
+		    is_type_generic(t->Proc.params)) {
+			return true;
+		}
+		if (t->Proc.result_count > 0 &&
+		    is_type_generic(t->Proc.results)) {
+			return true;
+		}
+		break;
+
+	// case Type_Record:
+	// 	GB_ASSERT(t->Record.kind != TypeRecord_Enum);
+	// 	for (isize i = 0; i < t->Record.field_count; i++) {
+	// 	    if (is_type_generic(t->Record.fields[i]->type)) {
+	// 	    	return true;
+	// 	    }
+	// 	}
+	// 	for (isize i = 1; i < t->Record.variant_count; i++) {
+	// 	    if (is_type_generic(t->Record.variants[i]->type)) {
+	// 	    	return true;
+	// 	    }
+	// 	}
+	// 	break;
+
+	case Type_Map:
+		if (is_type_generic(t->Map.key)) {
+			return true;
+		}
+		if (is_type_generic(t->Map.value)) {
+			return true;
+		}
+		break;
+
+	}
+
+	return false;
+}
+
 
 bool type_has_nil(Type *t) {
 	t = base_type(t);