lang: ast: implement parsing of right-parenthesis in expressions

lang/ast/expr.c

@@ -492,6 +492,50 @@ static struct token_parse_result parse_left_paren(
 static struct token_parse_result parse_right_paren(
 	struct ivy_parser *ctx, struct ivy_token *tok)
 {
+	struct expr_parser_state *state
+		= parser_get_state(ctx, struct expr_parser_state);
+
+	b_queue_entry *entry = NULL;
+
+	while (true) {
+		entry = b_queue_last(&state->s_operator_stack);
+		if (!entry) {
+			break;
+		}
+
+		struct ivy_ast_node *node
+			= b_unbox(struct ivy_ast_node, entry, n_entry);
+		if (!node) {
+			/* this should never happen */
+			return PARSE_RESULT(IVY_ERR_INTERNAL_FAILURE, 0);
+		}
+
+		if (node->n_type != IVY_AST_OP) {
+			b_queue_delete(&state->s_operator_stack, entry);
+			b_queue_push_back(&state->s_output_queue, entry);
+			continue;
+		}
+
+		struct ivy_ast_op_node *op_node = (struct ivy_ast_op_node *)node;
+
+		if (op_node->n_op->op_id == IVY_OP_LEFT_PAREN) {
+			break;
+		}
+
+		b_queue_delete(&state->s_operator_stack, entry);
+		b_queue_push_back(&state->s_output_queue, entry);
+		entry = NULL;
+	}
+
+	if (!entry) {
+		/* mismatched parentheses */
+		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
+	}
+
+	struct ivy_ast_node *paren = b_unbox(struct ivy_ast_node, entry, n_entry);
+	b_queue_delete(&state->s_operator_stack, entry);
+	ivy_ast_node_destroy(paren);
+
 	return PARSE_RESULT(IVY_OK, 0);
 }