Try `try` and `or_else` built-in procedures with operators `try` and `try else`

10 files changed, 318 insertions, 290 deletions

diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index 23c489482..baa5d6ced 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -47,181 +47,6 @@ BuiltinTypeIsProc *builtin_type_is_procs[BuiltinProc__type_simple_boolean_end -
 	type_has_nil,
 };
 
-void check_promote_optional_ok(CheckerContext *c, Operand *x, Type **val_type_, Type **ok_type_) {
-	switch (x->mode) {
-	case Addressing_MapIndex:
-	case Addressing_OptionalOk:
-	case Addressing_OptionalOkPtr:
-		if (val_type_) *val_type_ = x->type;
-		break;
-	default:
-		if (ok_type_) *ok_type_ = x->type;
-		return;
-	}
-
-	Ast *expr = unparen_expr(x->expr);
-
-	if (expr->kind == Ast_CallExpr) {
-		Type *pt = base_type(type_of_expr(expr->CallExpr.proc));
-		if (is_type_proc(pt)) {
-			Type *tuple = pt->Proc.results;
-			add_type_and_value(&c->checker->info, x->expr, x->mode, tuple, x->value);
-
-			if (pt->Proc.result_count >= 2) {
-				if (ok_type_) *ok_type_ = tuple->Tuple.variables[1]->type;
-			}
-			expr->CallExpr.optional_ok_one = false;
-			x->type = tuple;
-			return;
-		}
-	}
-
-	Type *tuple = make_optional_ok_type(x->type);
-	if (ok_type_) *ok_type_ = tuple->Tuple.variables[1]->type;
-	add_type_and_value(&c->checker->info, x->expr, x->mode, tuple, x->value);
-	x->type = tuple;
-	GB_ASSERT(is_type_tuple(type_of_expr(x->expr)));
-}
-
-void check_try_split_types(CheckerContext *c, Operand *x, String const &name, Type **left_type_, Type **right_type_) {
-	Type *left_type = nullptr;
-	Type *right_type = nullptr;
-	if (x->type->kind == Type_Tuple) {
-		auto const &vars = x->type->Tuple.variables;
-		auto lhs = array_slice(vars, 0, vars.count-1);
-		auto rhs = vars[vars.count-1];
-		if (lhs.count == 1) {
-			left_type = lhs[0]->type;
-		} else if (lhs.count != 0) {
-			left_type = alloc_type_tuple();
-			left_type->Tuple.variables = array_make_from_ptr(lhs.data, lhs.count, lhs.count);
-		}
-
-		right_type = rhs->type;
-	} else {
-		check_promote_optional_ok(c, x, &left_type, &right_type);
-	}
-
-	if (left_type_)  *left_type_  = left_type;
-	if (right_type_) *right_type_ = right_type;
-
-	if (!type_has_nil(right_type) && !is_type_boolean(right_type)) {
-		gbString str = type_to_string(right_type);
-		error(x->expr, "'%.*s' expects an \"optional ok\" like value, or an n-valued expression where the last value is either a boolean or can be compared against 'nil', got %s", LIT(name), str);
-		gb_string_free(str);
-	}
-}
-
-bool check_builtin_try(CheckerContext *c, Operand *operand, String const &name, Ast *call, Type *type_hint) {
-	ast_node(ce, CallExpr, call);
-
-	Operand x = {};
-	check_multi_expr_with_type_hint(c, &x, ce->args[0], type_hint);
-	if (x.mode == Addressing_Invalid) {
-		return false;
-	}
-
-	if (c->in_defer) {
-		error(call, "'%.*s' cannot be used within a defer statement", LIT(name));
-	}
-
-	Type *left_type = nullptr;
-	Type *right_type = nullptr;
-	check_try_split_types(c, &x, name, &left_type, &right_type);
-	add_type_and_value(&c->checker->info, ce->args[0], x.mode, x.type, x.value);
-
-	if (c->curr_proc_sig == nullptr) {
-		error(call, "'%.*s' can only be used within a procedure", LIT(name));
-	}
-	Type *proc_type = base_type(c->curr_proc_sig);
-	GB_ASSERT(proc_type->kind == Type_Proc);
-	Type *result_type = proc_type->Proc.results;
-	if (result_type == nullptr) {
-		error(call, "'%.*s' requires the current procedure to have at least one return value", LIT(name));
-	} else {
-		GB_ASSERT(result_type->kind == Type_Tuple);
-
-		auto const &vars = result_type->Tuple.variables;
-		Type *end_type = vars[vars.count-1]->type;
-
-		if (vars.count > 1) {
-			if (!proc_type->Proc.has_named_results) {
-				error(call, "'%.*s' within a procedure with more than 1 return value requires that the return values are named, allowing for early return", LIT(name));
-			}
-		}
-
-		Operand rhs = {};
-		rhs.type = right_type;
-		rhs.mode = Addressing_Value;
-
-		// TODO(bill): better error message
-		if (!check_is_assignable_to(c, &rhs, end_type)) {
-			gbString a = type_to_string(right_type);
-			gbString b = type_to_string(end_type);
-			gbString ret_type = type_to_string(result_type);
-			error(call, "Cannot assign end value of type '%s' to '%s' in '%.*s'", a, b, LIT(name));
-			if (vars.count == 1) {
-				error_line("\tProcedure return value type: %s\n", ret_type);
-			} else {
-				error_line("\tProcedure return value types: (%s)\n", ret_type);
-			}
-			gb_string_free(ret_type);
-			gb_string_free(b);
-			gb_string_free(a);
-		}
-	}
-
-
-	if (left_type != nullptr) {
-		operand->mode = Addressing_Value;
-		operand->type = left_type;
-	} else {
-		operand->mode = Addressing_NoValue;
-		operand->type = nullptr;
-	}
-
-	return true;
-}
-
-bool check_builtin_or_else(CheckerContext *c, Operand *operand, String const &name, Ast *call, Type *type_hint) {
-	ast_node(ce, CallExpr, call);
-
-	Operand x = {};
-	Operand y = {};
-	check_multi_expr_with_type_hint(c, &x, ce->args[0], type_hint);
-	if (x.mode == Addressing_Invalid) {
-		return false;
-	}
-
-	check_multi_expr(c, &y, ce->args[1]);
-	error_operand_no_value(&y);
-	if (y.mode == Addressing_Invalid) {
-		return false;
-	}
-
-	Type *left_type = nullptr;
-	Type *right_type = nullptr;
-	check_try_split_types(c, &x, name, &left_type, &right_type);
-	add_type_and_value(&c->checker->info, ce->args[0], x.mode, x.type, x.value);
-
-	if (left_type != nullptr) {
-		check_assignment(c, &y, left_type, name);
-	} else {
-		// TODO(bill): better error message
-		error(call, "'%.*s' does not return a value", LIT(name));
-	}
-
-
-	if (left_type == nullptr) {
-		left_type = t_invalid;
-	}
-	operand->mode = Addressing_Value;
-	operand->type = left_type;
-
-	return true;
-}
-
-
 bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32 id, Type *type_hint) {
 	ast_node(ce, CallExpr, call);
 	if (ce->inlining != ProcInlining_none) {
@@ -259,10 +84,6 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		// NOTE(bill): The first arg may be a Type, this will be checked case by case
 		break;
 
-	case BuiltinProc_try:
-	case BuiltinProc_or_else:
-		// NOTE(bill): The first arg may be a tuple
-		break;
 
 	case BuiltinProc_DIRECTIVE: {
 		ast_node(bd, BasicDirective, ce->proc);
@@ -1891,11 +1712,6 @@ bool check_builtin_procedure(CheckerContext *c, Operand *operand, Ast *call, i32
 		break;
 	}
 
-	case BuiltinProc_try:
-		return check_builtin_try(c, operand, builtin_name, call, type_hint);
-	case BuiltinProc_or_else:
-		return check_builtin_or_else(c, operand, builtin_name, call, type_hint);
-
 	case BuiltinProc_simd_vector: {
 		Operand x = {};
 		Operand y = {};
diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 57d10f60e..67cf50a75 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -73,6 +73,7 @@ typedef CALL_ARGUMENT_CHECKER(CallArgumentCheckerType);
 void     check_expr                     (CheckerContext *c, Operand *operand, Ast *expression);
 void     check_multi_expr               (CheckerContext *c, Operand *operand, Ast *expression);
 void     check_multi_expr_or_type       (CheckerContext *c, Operand *operand, Ast *expression);
+void     check_multi_expr_with_type_hint(CheckerContext *c, Operand *o, Ast *e, Type *type_hint);
 void     check_expr_or_type             (CheckerContext *c, Operand *operand, Ast *expression, Type *type_hint);
 ExprKind check_expr_base                (CheckerContext *c, Operand *operand, Ast *expression, Type *type_hint);
 void     check_expr_with_type_hint      (CheckerContext *c, Operand *o, Ast *e, Type *t);
@@ -6195,6 +6196,191 @@ ExprKind check_implicit_selector_expr(CheckerContext *c, Operand *o, Ast *node,
 	return Expr_Expr;
 }
 
+
+void check_promote_optional_ok(CheckerContext *c, Operand *x, Type **val_type_, Type **ok_type_) {
+	switch (x->mode) {
+	case Addressing_MapIndex:
+	case Addressing_OptionalOk:
+	case Addressing_OptionalOkPtr:
+		if (val_type_) *val_type_ = x->type;
+		break;
+	default:
+		if (ok_type_) *ok_type_ = x->type;
+		return;
+	}
+
+	Ast *expr = unparen_expr(x->expr);
+
+	if (expr->kind == Ast_CallExpr) {
+		Type *pt = base_type(type_of_expr(expr->CallExpr.proc));
+		if (is_type_proc(pt)) {
+			Type *tuple = pt->Proc.results;
+			add_type_and_value(&c->checker->info, x->expr, x->mode, tuple, x->value);
+
+			if (pt->Proc.result_count >= 2) {
+				if (ok_type_) *ok_type_ = tuple->Tuple.variables[1]->type;
+			}
+			expr->CallExpr.optional_ok_one = false;
+			x->type = tuple;
+			return;
+		}
+	}
+
+	Type *tuple = make_optional_ok_type(x->type);
+	if (ok_type_) *ok_type_ = tuple->Tuple.variables[1]->type;
+	add_type_and_value(&c->checker->info, x->expr, x->mode, tuple, x->value);
+	x->type = tuple;
+	GB_ASSERT(is_type_tuple(type_of_expr(x->expr)));
+}
+
+void check_try_split_types(CheckerContext *c, Operand *x, String const &name, Type **left_type_, Type **right_type_) {
+	Type *left_type = nullptr;
+	Type *right_type = nullptr;
+	if (x->type->kind == Type_Tuple) {
+		auto const &vars = x->type->Tuple.variables;
+		auto lhs = array_slice(vars, 0, vars.count-1);
+		auto rhs = vars[vars.count-1];
+		if (lhs.count == 1) {
+			left_type = lhs[0]->type;
+		} else if (lhs.count != 0) {
+			left_type = alloc_type_tuple();
+			left_type->Tuple.variables = array_make_from_ptr(lhs.data, lhs.count, lhs.count);
+		}
+
+		right_type = rhs->type;
+	} else {
+		check_promote_optional_ok(c, x, &left_type, &right_type);
+	}
+
+	if (left_type_)  *left_type_  = left_type;
+	if (right_type_) *right_type_ = right_type;
+
+	if (!type_has_nil(right_type) && !is_type_boolean(right_type)) {
+		gbString str = type_to_string(right_type);
+		error(x->expr, "'%.*s' expects an \"optional ok\" like value, or an n-valued expression where the last value is either a boolean or can be compared against 'nil', got %s", LIT(name), str);
+		gb_string_free(str);
+	}
+}
+
+
+ExprKind check_try_expr(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) {
+	String name = str_lit("try");
+
+	ast_node(te, TryExpr, node);
+
+	Operand x = {};
+	check_multi_expr_with_type_hint(c, &x, te->expr, type_hint);
+	if (x.mode == Addressing_Invalid) {
+		o->mode = Addressing_Value;
+		o->type = t_invalid;
+		return Expr_Expr;
+	}
+
+	if (c->in_defer) {
+		error(node, "'%.*s' cannot be used within a defer statement", LIT(name));
+	}
+
+	Type *left_type = nullptr;
+	Type *right_type = nullptr;
+	check_try_split_types(c, &x, name, &left_type, &right_type);
+	add_type_and_value(&c->checker->info, te->expr, x.mode, x.type, x.value);
+
+	if (c->curr_proc_sig == nullptr) {
+		error(node, "'%.*s' can only be used within a procedure", LIT(name));
+	}
+	Type *proc_type = base_type(c->curr_proc_sig);
+	GB_ASSERT(proc_type->kind == Type_Proc);
+	Type *result_type = proc_type->Proc.results;
+	if (result_type == nullptr) {
+		error(node, "'%.*s' requires the current procedure to have at least one return value", LIT(name));
+	} else {
+		GB_ASSERT(result_type->kind == Type_Tuple);
+
+		auto const &vars = result_type->Tuple.variables;
+		Type *end_type = vars[vars.count-1]->type;
+
+		if (vars.count > 1) {
+			if (!proc_type->Proc.has_named_results) {
+				error(node, "'%.*s' within a procedure with more than 1 return value requires that the return values are named, allowing for early return", LIT(name));
+			}
+		}
+
+		Operand rhs = {};
+		rhs.type = right_type;
+		rhs.mode = Addressing_Value;
+
+		// TODO(bill): better error message
+		if (!check_is_assignable_to(c, &rhs, end_type)) {
+			gbString a = type_to_string(right_type);
+			gbString b = type_to_string(end_type);
+			gbString ret_type = type_to_string(result_type);
+			error(node, "Cannot assign end value of type '%s' to '%s' in '%.*s'", a, b, LIT(name));
+			if (vars.count == 1) {
+				error_line("\tProcedure return value type: %s\n", ret_type);
+			} else {
+				error_line("\tProcedure return value types: (%s)\n", ret_type);
+			}
+			gb_string_free(ret_type);
+			gb_string_free(b);
+			gb_string_free(a);
+		}
+	}
+
+
+	if (left_type != nullptr) {
+		o->mode = Addressing_Value;
+		o->type = left_type;
+	} else {
+		o->mode = Addressing_NoValue;
+		o->type = nullptr;
+	}
+
+	return Expr_Expr;
+}
+ExprKind check_try_else_expr(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) {
+	String name = str_lit("try else");
+
+	ast_node(te, TryElseExpr, node);
+
+	Operand x = {};
+	Operand y = {};
+	check_multi_expr_with_type_hint(c, &x, te->expr, type_hint);
+	if (x.mode == Addressing_Invalid) {
+		o->mode = Addressing_Value;
+		o->type = t_invalid;
+		return Expr_Expr;
+	}
+
+	check_multi_expr_with_type_hint(c, &y, te->else_expr, x.type);
+	error_operand_no_value(&y);
+	if (y.mode == Addressing_Invalid) {
+		o->mode = Addressing_Value;
+		o->type = t_invalid;
+		return Expr_Expr;
+	}
+
+	Type *left_type = nullptr;
+	Type *right_type = nullptr;
+	check_try_split_types(c, &x, name, &left_type, &right_type);
+	add_type_and_value(&c->checker->info, te->expr, x.mode, x.type, x.value);
+
+	if (left_type != nullptr) {
+		check_assignment(c, &y, left_type, name);
+	} else {
+		// TODO(bill): better error message
+		error(node, "'%.*s' does not return a value", LIT(name));
+	}
+
+	if (left_type == nullptr) {
+		left_type = t_invalid;
+	}
+	o->mode = Addressing_Value;
+	o->type = left_type;
+
+	return Expr_Expr;
+}
+
+
 ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type *type_hint) {
 	u32 prev_state_flags = c->state_flags;
 	defer (c->state_flags = prev_state_flags);
@@ -7564,7 +7750,13 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 		}
 	case_end;
 
+	case_ast_node(te, TryExpr, node);
+		return check_try_expr(c, o, node, type_hint);
+	case_end;
 
+	case_ast_node(te, TryElseExpr, node);
+		return check_try_else_expr(c, o, node, type_hint);
+	case_end;
 
 	case_ast_node(se, SelectorExpr, node);
 		check_selector(c, o, node, type_hint);
diff --git a/src/checker_builtin_procs.hpp b/src/checker_builtin_procs.hpp
index a72231f8b..57b5d7eb9 100644
--- a/src/checker_builtin_procs.hpp
+++ b/src/checker_builtin_procs.hpp
@@ -33,9 +33,6 @@ enum BuiltinProcId {
 	BuiltinProc_soa_zip,
 	BuiltinProc_soa_unzip,
 
-	BuiltinProc_try,
-	BuiltinProc_or_else,
-
 	BuiltinProc_DIRECTIVE, // NOTE(bill): This is used for specialized hash-prefixed procedures
 
 	// "Intrinsics"
@@ -266,9 +263,6 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("soa_zip"),          1, true,  Expr_Expr, BuiltinProcPkg_builtin},
 	{STR_LIT("soa_unzip"),        1, false, Expr_Expr, BuiltinProcPkg_builtin},
 
-	{STR_LIT("try"),              1, false, Expr_Expr, BuiltinProcPkg_builtin},
-	{STR_LIT("or_else"),          2, false, Expr_Expr, BuiltinProcPkg_builtin},
-
 	{STR_LIT(""),                 0, true,  Expr_Expr, BuiltinProcPkg_builtin}, // DIRECTIVE
 
 
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index a3561056c..4c4c015ba 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -2756,9 +2756,7 @@ lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool ignore_body)
 		lbValue *found = string_map_get(&m->members, key);
 		if (found) {
 			lb_add_entity(m, entity, *found);
-			lbProcedure **p_found = string_map_get(&m->procedures, key);
-			GB_ASSERT(p_found != nullptr);
-			return *p_found;
+			return string_map_must_get(&m->procedures, key);
 		}
 	}
 
@@ -5339,7 +5337,10 @@ void lb_build_assignment(lbProcedure *p, Array<lbAddr> &lvals, Slice<Ast *> cons
 	}
 }
 
-void lb_build_return_stmt_internal(lbProcedure *p, bool return_by_pointer, lbValue const &res) {
+void lb_build_return_stmt_internal(lbProcedure *p, lbValue const &res) {
+	lbFunctionType *ft = lb_get_function_type(p->module, p, p->type);
+	bool return_by_pointer = ft->ret.kind == lbArg_Indirect;
+
 	if (return_by_pointer) {
 		if (res.value != nullptr) {
 			LLVMBuildStore(p->builder, res.value, p->return_ptr.addr.value);
@@ -5383,9 +5384,8 @@ void lb_build_return_stmt(lbProcedure *p, Slice<Ast *> const &return_results) {
 	} else if (return_count == 1) {
 		Entity *e = tuple->variables[0];
 		if (res_count == 0) {
-			lbValue *found = map_get(&p->module->values, hash_entity(e));
-			GB_ASSERT(found);
-			res = lb_emit_load(p, *found);
+			lbValue found = map_must_get(&p->module->values, hash_entity(e));
+			res = lb_emit_load(p, found);
 		} else {
 			res = lb_build_expr(p, return_results[0]);
 			res = lb_emit_conv(p, res, e->type);
@@ -5393,9 +5393,8 @@ void lb_build_return_stmt(lbProcedure *p, Slice<Ast *> const &return_results) {
 		if (p->type->Proc.has_named_results) {
 			// NOTE(bill): store the named values before returning
 			if (e->token.string != "") {
-				lbValue *found = map_get(&p->module->values, hash_entity(e));
-				GB_ASSERT(found != nullptr);
-				lb_emit_store(p, *found, lb_emit_conv(p, res, e->type));
+				lbValue found = map_must_get(&p->module->values, hash_entity(e));
+				lb_emit_store(p, found, lb_emit_conv(p, res, e->type));
 			}
 		}
 
@@ -5419,9 +5418,8 @@ void lb_build_return_stmt(lbProcedure *p, Slice<Ast *> const &return_results) {
 		} else {
 			for (isize res_index = 0; res_index < return_count; res_index++) {
 				Entity *e = tuple->variables[res_index];
-				lbValue *found = map_get(&p->module->values, hash_entity(e));
-				GB_ASSERT(found);
-				lbValue res = lb_emit_load(p, *found);
+				lbValue found = map_must_get(&p->module->values, hash_entity(e));
+				lbValue res = lb_emit_load(p, found);
 				array_add(&results, res);
 			}
 		}
@@ -5442,9 +5440,7 @@ void lb_build_return_stmt(lbProcedure *p, Slice<Ast *> const &return_results) {
 				if (e->token.string == "") {
 					continue;
 				}
-				lbValue *found = map_get(&p->module->values, hash_entity(e));
-				GB_ASSERT(found != nullptr);
-				named_results[i] = *found;
+				named_results[i] = map_must_get(&p->module->values, hash_entity(e));
 				values[i] = lb_emit_conv(p, results[i], e->type);
 			}
 
@@ -5483,7 +5479,7 @@ void lb_build_return_stmt(lbProcedure *p, Slice<Ast *> const &return_results) {
 
 		res = lb_emit_load(p, res);
 	}
-	lb_build_return_stmt_internal(p, return_by_pointer, res);
+	lb_build_return_stmt_internal(p, res);
 }
 
 void lb_build_if_stmt(lbProcedure *p, Ast *node) {
@@ -9554,15 +9550,11 @@ lbValue lb_soa_unzip(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv) {
 	return lb_addr_load(p, res);
 }
 
-lbValue lb_emit_try(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv) {
-	Ast *arg = ce->args[0];
-
+void lb_emit_try_lhs_rhs(lbProcedure *p, Ast *arg, TypeAndValue const &tv, lbValue *lhs_, lbValue *rhs_) {
 	lbValue lhs = {};
 	lbValue rhs = {};
 
-	TypeAndValue const &arg_tav = type_and_value_of_expr(arg);
 	lbValue value = lb_build_expr(p, arg);
-
 	if (is_type_tuple(value.type)) {
 		i32 n = cast(i32)(value.type->Tuple.variables.count-1);
 		if (value.type->Tuple.variables.count == 2) {
@@ -9582,52 +9574,54 @@ lbValue lb_emit_try(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv) {
 
 	GB_ASSERT(rhs.value != nullptr);
 
-	lbValue do_early_return = {};
+	if (lhs_) *lhs_ = lhs;
+	if (rhs_) *rhs_ = rhs;
+}
+
+
+lbValue lb_emit_try_has_value(lbProcedure *p, lbValue rhs) {
+	lbValue has_value = {};
 	if (is_type_boolean(rhs.type)) {
-		do_early_return = lb_emit_unary_arith(p, Token_Not, rhs, t_bool);
+		has_value = rhs;
 	} else {
-		GB_ASSERT(type_has_nil(rhs.type));
-		do_early_return = lb_emit_comp_against_nil(p, Token_NotEq, rhs);
+		GB_ASSERT_MSG(type_has_nil(rhs.type), "%s", type_to_string(rhs.type));
+		has_value = lb_emit_comp_against_nil(p, Token_CmpEq, rhs);
 	}
-
-	GB_ASSERT(do_early_return.value != nullptr);
-
+	GB_ASSERT(has_value.value != nullptr);
+	return has_value;
+}
+lbValue lb_emit_try(lbProcedure *p, Ast *arg, TypeAndValue const &tv) {
+	lbValue lhs = {};
+	lbValue rhs = {};
+	lb_emit_try_lhs_rhs(p, arg, tv, &lhs, &rhs);
 
 	lbBlock *return_block = lb_create_block(p, "try.return", false);
 	lbBlock *continue_block = lb_create_block(p, "try.continue", false);
-	lb_emit_if(p, do_early_return, return_block, continue_block);
+	lb_emit_if(p, lb_emit_try_has_value(p, rhs), continue_block, return_block);
 	lb_start_block(p, return_block);
 
 	{
 		Type *proc_type = base_type(p->type);
-		// TODO(bill): multiple return values
 		Type *results = proc_type->Proc.results;
 		GB_ASSERT(results != nullptr && results->kind == Type_Tuple);
 		TypeTuple *tuple = &results->Tuple;
 
-		isize return_count = tuple->variables.count;
-		// TODO(bill) multiple
-		GB_ASSERT(return_count != 0);
-
-		lbFunctionType *ft = lb_get_function_type(p->module, p, proc_type);
-		bool return_by_pointer = ft->ret.kind == lbArg_Indirect;
+		GB_ASSERT(tuple->variables.count != 0);
 
+		Entity *end_entity = tuple->variables[tuple->variables.count-1];
+		rhs = lb_emit_conv(p, rhs, end_entity->type);
 		if (p->type->Proc.has_named_results) {
-			Entity *e = tuple->variables[tuple->variables.count-1];
+			GB_ASSERT(end_entity->token.string.len != 0);
+
 			// NOTE(bill): store the named values before returning
-			if (e->token.string != "") {
-				lbValue *found = map_get(&p->module->values, hash_entity(e));
-				GB_ASSERT(found != nullptr);
-				lb_emit_store(p, *found, lb_emit_conv(p, rhs, e->type));
-			}
+			lbValue found = map_must_get(&p->module->values, hash_entity(end_entity));
+			lb_emit_store(p, found, rhs);
 
 			lb_build_return_stmt(p, {});
 		} else {
-			GB_ASSERT(return_count == 1);
-			Entity *e = tuple->variables[0];
-			lb_build_return_stmt_internal(p, return_by_pointer, lb_emit_conv(p, rhs, e->type));
+			GB_ASSERT(tuple->variables.count == 1);
+			lb_build_return_stmt_internal(p, rhs);
 		}
-
 	}
 
 	lb_start_block(p, continue_block);
@@ -9639,57 +9633,20 @@ lbValue lb_emit_try(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv) {
 }
 
 
-lbValue lb_emit_or_else(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv) {
-	Ast *arg = ce->args[0];
-	Ast *else_value = ce->args[1];
-
+lbValue lb_emit_try_else(lbProcedure *p, Ast *arg, Ast *else_expr, TypeAndValue const &tv) {
 	lbValue lhs = {};
 	lbValue rhs = {};
-
-	TypeAndValue const &arg_tav = type_and_value_of_expr(arg);
-	if (unparen_expr(arg)->kind == Ast_TypeAssertion) {
-		GB_ASSERT_MSG(is_type_tuple(arg_tav.type), "%s", type_to_string(arg_tav.type));
-	}
-	lbValue value = lb_build_expr(p, arg);
-
-	if (is_type_tuple(value.type)) {
-		i32 end_index = cast(i32)(value.type->Tuple.variables.count-1);
-		if (value.type->Tuple.variables.count == 2) {
-			lhs = lb_emit_struct_ev(p, value, 0);
-		} else {
-			lbAddr lhs_addr = lb_add_local_generated(p, tv.type, false);
-			lbValue lhs_ptr = lb_addr_get_ptr(p, lhs_addr);
-			for (i32 i = 0; i < end_index; i++) {
-				lb_emit_store(p, lb_emit_struct_ep(p, lhs_ptr, i), lb_emit_struct_ev(p, value, i));
-			}
-			lhs = lb_addr_load(p, lhs_addr);
-		}
-		rhs = lb_emit_struct_ev(p, value, end_index);
-	} else {
-		rhs = value;
-	}
-
-	GB_ASSERT(rhs.value != nullptr);
-
-	lbValue has_value = {};
-	if (is_type_boolean(rhs.type)) {
-		has_value = rhs;
-	} else {
-		GB_ASSERT_MSG(type_has_nil(rhs.type), "%s", type_to_string(rhs.type));
-		has_value = lb_emit_comp_against_nil(p, Token_CmpEq, rhs);
-	}
-
-	GB_ASSERT(has_value.value != nullptr);
+	lb_emit_try_lhs_rhs(p, arg, tv, &lhs, &rhs);
 
 	LLVMValueRef incoming_values[2] = {};
 	LLVMBasicBlockRef incoming_blocks[2] = {};
 
-	GB_ASSERT(else_value != nullptr);
+	GB_ASSERT(else_expr != nullptr);
 	lbBlock *then  = lb_create_block(p, "or_else.then");
 	lbBlock *done  = lb_create_block(p, "or_else.done"); // NOTE(bill): Append later
 	lbBlock *else_ = lb_create_block(p, "or_else.else");
 
-	lb_emit_if(p, has_value, then, else_);
+	lb_emit_if(p, lb_emit_try_has_value(p, rhs), then, else_);
 	lb_start_block(p, then);
 
 	Type *type = default_type(tv.type);
@@ -9699,7 +9656,7 @@ lbValue lb_emit_or_else(lbProcedure *p, AstCallExpr *ce, TypeAndValue const &tv)
 	lb_emit_jump(p, done);
 	lb_start_block(p, else_);
 
-	incoming_values[1] = lb_emit_conv(p, lb_build_expr(p, else_value), type).value;
+	incoming_values[1] = lb_emit_conv(p, lb_build_expr(p, else_expr), type).value;
 
 	lb_emit_jump(p, done);
 	lb_start_block(p, done);
@@ -10107,13 +10064,6 @@ lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValue const &tv,
 	case BuiltinProc_soa_unzip:
 		return lb_soa_unzip(p, ce, tv);
 
-	case BuiltinProc_try:
-		return lb_emit_try(p, ce, tv);
-
-	case BuiltinProc_or_else:
-		return lb_emit_or_else(p, ce, tv);
-
-
 	// "Intrinsics"
 
 	case BuiltinProc_alloca:
@@ -12833,6 +12783,14 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 		return lb_build_binary_expr(p, expr);
 	case_end;
 
+	case_ast_node(te, TryExpr, expr);
+		return lb_emit_try(p, te->expr, tv);
+	case_end;
+
+	case_ast_node(te, TryElseExpr, expr);
+		return lb_emit_try_else(p, te->expr, te->else_expr, tv);
+	case_end;
+
 	case_ast_node(pl, ProcLit, expr);
 		return lb_generate_anonymous_proc_lit(p->module, p->name, expr, p);
 	case_end;
@@ -12904,9 +12862,7 @@ lbValue lb_build_expr(lbProcedure *p, Ast *expr) {
 }
 
 lbAddr lb_get_soa_variable_addr(lbProcedure *p, Entity *e) {
-	lbAddr *found = map_get(&p->module->soa_values, hash_entity(e));
-	GB_ASSERT(found != nullptr);
-	return *found;
+	return map_must_get(&p->module->soa_values, hash_entity(e));
 }
 lbValue lb_get_using_variable(lbProcedure *p, Entity *e) {
 	GB_ASSERT(e->kind == Entity_Variable && e->flags & EntityFlag_Using);
@@ -14406,7 +14362,6 @@ lbValue lb_find_runtime_value(lbModule *m, String const &name) {
 }
 lbValue lb_find_package_value(lbModule *m, String const &pkg, String const &name) {
 	Entity *e = find_entity_in_pkg(m->info, pkg, name);
-	lbValue *found = map_get(&m->values, hash_entity(e));
 	return lb_find_value_from_entity(m, e);
 }
 
diff --git a/src/map.cpp b/src/map.cpp
index 85836fccb..fc23c9aec 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -69,6 +69,7 @@ struct Map {
 template <typename T> void map_init             (Map<T> *h, gbAllocator a, isize capacity = 16);
 template <typename T> void map_destroy          (Map<T> *h);
 template <typename T> T *  map_get              (Map<T> *h, HashKey const &key);
+template <typename T> T &  map_must_get         (Map<T> *h, HashKey const &key);
 template <typename T> void map_set              (Map<T> *h, HashKey const &key, T const &value);
 template <typename T> void map_remove           (Map<T> *h, HashKey const &key);
 template <typename T> void map_clear            (Map<T> *h);
@@ -203,6 +204,13 @@ T *map_get(Map<T> *h, HashKey const &key) {
 }
 
 template <typename T>
+T &map_must_get(Map<T> *h, HashKey const &key) {
+	isize index = map__find(h, key).entry_index;
+	GB_ASSERT(index >= 0);
+	return h->entries[index].value;
+}
+
+template <typename T>
 void map_set(Map<T> *h, HashKey const &key, T const &value) {
 	isize index;
 	MapFindResult fr;
diff --git a/src/parser.cpp b/src/parser.cpp
index 50584eb51..641c4141f 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -199,6 +199,15 @@ Ast *clone_ast(Ast *node) {
 		n->AutoCast.expr = clone_ast(n->AutoCast.expr);
 		break;
 
+	case Ast_TryExpr:
+		n->TryExpr.expr = clone_ast(n->TryExpr.expr);
+		break;
+
+	case Ast_TryElseExpr:
+		n->TryElseExpr.expr = clone_ast(n->TryElseExpr.expr);
+		n->TryElseExpr.else_expr = clone_ast(n->TryElseExpr.else_expr);
+		break;
+
 	case Ast_InlineAsmExpr:
 		n->InlineAsmExpr.param_types        = clone_ast_array(n->InlineAsmExpr.param_types);
 		n->InlineAsmExpr.return_type        = clone_ast(n->InlineAsmExpr.return_type);
@@ -680,6 +689,22 @@ Ast *ast_auto_cast(AstFile *f, Token token, Ast *expr) {
 	return result;
 }
 
+Ast *ast_try_expr(AstFile *f, Token token, Ast *expr) {
+	Ast *result = alloc_ast_node(f, Ast_TryExpr);
+	result->TryExpr.token = token;
+	result->TryExpr.expr  = expr;
+	return result;
+}
+Ast *ast_try_else_expr(AstFile *f, Token try_token, Ast *expr, Token else_token, Ast *else_expr) {
+	Ast *result = alloc_ast_node(f, Ast_TryElseExpr);
+	result->TryElseExpr.try_token  = try_token;
+	result->TryElseExpr.expr       = expr;
+	result->TryElseExpr.else_token = else_token;
+	result->TryElseExpr.else_expr  = else_expr;
+	return result;
+}
+
+
 Ast *ast_inline_asm_expr(AstFile *f, Token token, Token open, Token close,
                          Array<Ast *> const &param_types,
                          Ast *return_type,
@@ -2723,6 +2748,16 @@ Ast *parse_unary_expr(AstFile *f, bool lhs) {
 		return ast_auto_cast(f, token, expr);
 	}
 
+	case Token_try: {
+		Token try_token = advance_token(f);
+		Ast *expr = parse_unary_expr(f, lhs);
+		if (f->curr_token.kind == Token_else) {
+			Token else_token = advance_token(f);
+			Ast *else_expr = parse_expr(f, lhs);
+			return ast_try_else_expr(f, try_token, expr, else_token, else_expr);
+		}
+		return ast_try_expr(f, try_token, expr);
+	}
 
 	case Token_Add:
 	case Token_Sub:
diff --git a/src/parser.hpp b/src/parser.hpp
index ad2b8c260..b999640a1 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -370,6 +370,8 @@ AST_KIND(_ExprBegin,  "",  bool) \
 	}) \
 	AST_KIND(TypeCast,      "type cast",           struct { Token token; Ast *type, *expr; }) \
 	AST_KIND(AutoCast,      "auto_cast",           struct { Token token; Ast *expr; }) \
+	AST_KIND(TryExpr,       "try expression",      struct { Token token; Ast *expr; }) \
+	AST_KIND(TryElseExpr,   "try else expression", struct { Token try_token; Ast *expr; Token else_token; Ast *else_expr; }) \
 	AST_KIND(InlineAsmExpr, "inline asm expression", struct { \
 		Token token; \
 		Token open, close; \
diff --git a/src/parser_pos.cpp b/src/parser_pos.cpp
index 921836afe..8f4fe4527 100644
--- a/src/parser_pos.cpp
+++ b/src/parser_pos.cpp
@@ -44,6 +44,8 @@ Token ast_token(Ast *node) {
 	case Ast_TypeAssertion:      return ast_token(node->TypeAssertion.expr);
 	case Ast_TypeCast:           return node->TypeCast.token;
 	case Ast_AutoCast:           return node->AutoCast.token;
+	case Ast_TryExpr:            return node->TryExpr.token;
+	case Ast_TryElseExpr:        return node->TryElseExpr.try_token;
 	case Ast_InlineAsmExpr:      return node->InlineAsmExpr.token;
 
 	case Ast_BadStmt:            return node->BadStmt.begin;
@@ -178,6 +180,8 @@ Token ast_end_token(Ast *node) {
 	case Ast_TypeAssertion:      return ast_end_token(node->TypeAssertion.type);
 	case Ast_TypeCast:           return ast_end_token(node->TypeCast.expr);
 	case Ast_AutoCast:           return ast_end_token(node->AutoCast.expr);
+	case Ast_TryExpr:            return ast_end_token(node->TryExpr.expr);
+	case Ast_TryElseExpr:        return ast_end_token(node->TryElseExpr.else_expr);
 	case Ast_InlineAsmExpr:      return node->InlineAsmExpr.close;
 
 	case Ast_BadStmt:            return node->BadStmt.end;
diff --git a/src/string_map.cpp b/src/string_map.cpp
index 7a446937a..09e125800 100644
--- a/src/string_map.cpp
+++ b/src/string_map.cpp
@@ -54,6 +54,10 @@ template <typename T> T *  string_map_get              (StringMap<T> *h, char co
 template <typename T> T *  string_map_get              (StringMap<T> *h, String const &key);
 template <typename T> T *  string_map_get              (StringMap<T> *h, StringHashKey const &key);
 
+template <typename T> T &  string_map_must_get         (StringMap<T> *h, char const *key);
+template <typename T> T &  string_map_must_get         (StringMap<T> *h, String const &key);
+template <typename T> T &  string_map_must_get         (StringMap<T> *h, StringHashKey const &key);
+
 template <typename T> void string_map_set              (StringMap<T> *h, StringHashKey const &key, T const &value);
 template <typename T> void string_map_set              (StringMap<T> *h, String const &key, T const &value);
 template <typename T> void string_map_set              (StringMap<T> *h, char const *key,   T const &value);
@@ -188,6 +192,23 @@ gb_inline T *string_map_get(StringMap<T> *h, char const *key) {
 }
 
 template <typename T>
+T &string_map_must_get(StringMap<T> *h, StringHashKey const &key) {
+	isize index = string_map__find(h, key).entry_index;
+	GB_ASSERT(index >= 0);
+	return h->entries[index].value;
+}
+
+template <typename T>
+gb_inline T &string_map_must_get(StringMap<T> *h, String const &key) {
+	return string_map_must_get(h, string_hash_string(key));
+}
+
+template <typename T>
+gb_inline T &string_map_must_get(StringMap<T> *h, char const *key) {
+	return string_map_must_get(h, string_hash_string(make_string_c(key)));
+}
+
+template <typename T>
 void string_map_set(StringMap<T> *h, StringHashKey const &key, T const &value) {
 	isize index;
 	StringMapFindResult fr;
diff --git a/src/tokenizer.cpp b/src/tokenizer.cpp
index edffb7446..130ee742a 100644
--- a/src/tokenizer.cpp
+++ b/src/tokenizer.cpp
@@ -117,6 +117,7 @@ TOKEN_KIND(Token__KeywordBegin, ""), \
 	TOKEN_KIND(Token_no_inline,   "no_inline"),   \
 	TOKEN_KIND(Token_context,     "context"),     \
 	TOKEN_KIND(Token_asm,         "asm"),         \
+	TOKEN_KIND(Token_try,         "try"),         \
 TOKEN_KIND(Token__KeywordEnd, ""), \
 	TOKEN_KIND(Token_Count, "")