ivy/lang/parse/cascade.c

#include "ctx.h"

#include <ivy/lang/ast.h>

bool parse_cascade(
	struct ivy_parser *parser, struct ivy_ast_node *first_msg,
	struct ivy_ast_node **out)
{
	if (!peek_symbol(parser, IVY_SYM_SEMICOLON)) {
		parse_trace(parser, "expected `;`");
		return false;
	}

	struct ivy_ast_msg_node *first = (struct ivy_ast_msg_node *)first_msg;
	if (first->n_base.n_type != IVY_AST_MSG) {
		parse_trace(parser, "cascade operand is not a message");
		return false;
	}

	struct ivy_ast_cascade_node *cascade = create_node(IVY_AST_CASCADE);
	cascade->n_recipient = first->n_recipient;
	first->n_recipient = NULL;
	fx_queue_push_back(&cascade->n_msg, &first->n_base.n_entry);

	bool ok = true;
	while (ok) {
		parse_linefeed(parser);

		if (!parse_symbol(parser, IVY_SYM_SEMICOLON)) {
			break;
		}

		parse_linefeed(parser);
		fx_queue_entry *entry = NULL;
		struct ivy_ast_msg_node *msg = NULL;
		struct ivy_token *tok = peek_token(parser);
		if (!tok) {
			break;
		}

		switch (tok->t_type) {
		case IVY_TOK_LABEL:
			ok = parse_keyword_msg(
				parser, cascade->n_recipient,
				EXPR_PARSE_STOP_SEMICOLON,
				(struct ivy_ast_node **)&msg);
			if (!ok) {
				break;
			}

			break;
		case IVY_TOK_IDENT:
			ok = parse_unary_msg(
				parser, cascade->n_recipient,
				(struct ivy_ast_node **)&msg);
			if (!ok) {
				break;
			}

			if (peek_symbol(parser, IVY_SYM_LEFT_PAREN)) {
				ok = parse_complex_msg(
					parser, generic_node(msg),
					(struct ivy_ast_node **)&msg);
			}

			break;
		default:
			parse_trace(parser, "expected message after `;`");
			ok = false;
			break;
		}

		msg->n_recipient = NULL;
		fx_queue_push_back(&cascade->n_msg, &msg->n_base.n_entry);
	}

	*out = generic_node(cascade);
	return true;
}