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\Types;

use \QuackCompiler\Ast\Types\GenericType;

class ParametricTypes
{
    private static $instances = [];

    public static function reset()
    {
        static::$instances = [];
    }

    public static function push(GenericType $generic)
    {
        static::$instances[] = $generic;
    }

    public static function name(GenericType $generic)
    {
        $index = ord('a');
        foreach (static::$instances as $instance) {
            if ($instance === $generic) {
                return chr($index);
            }

            $index++;
        }

        return '?';
    }
}