quack/quack

<?php
/**
 * Quack Compiler and toolkit
 * Copyright (C) 2015-2017 Quack and CONTRIBUTORS
 *
 * This file is part of Quack.
 *
 * Quack is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Quack is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Quack.  If not, see <http://www.gnu.org/licenses/>.
 */
namespace QuackCompiler\Parselets\Types;

use \QuackCompiler\Ast\Types\FunctionType;
use \QuackCompiler\Ast\Types\TupleType;
use \QuackCompiler\Lexer\Tag;
use \QuackCompiler\Lexer\Token;
use \QuackCompiler\Parselets\PrefixParselet;

class FunctionTypeParselet implements PrefixParselet
{
    public function parse($grammar, Token $token)
    {
        $parameters = [];
        $return = new TupleType();

        if ($grammar->reader->is(Tag::T_IDENT)) {
            $parameters[] = $grammar->_type();
        } else {
            $grammar->reader->match('[');
            if (!$grammar->reader->consumeIf(']')) {
                do {
                    $parameters[] = $grammar->_type();
                } while ($grammar->reader->consumeIf(','));

                $grammar->reader->match(']');
            }
        }

        if ($grammar->reader->consumeIf(':')) {
            $return = $grammar->_type();
        }

        return new FunctionType($parameters, $return);
    }
}