UniqueIteratorTrait.php

<?php declare(strict_types=1);
/*
 * This file is part of "irstea/ng-model-generator-bundle".
 *
 * "irstea/ng-model-generator-bundle" generates Typescript interfaces for Angular using api-platform metadata.
 * Copyright (C) 2018 IRSTEA
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 *
 * This program 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 and the GNU
 * Lesser General Public License along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */

namespace Irstea\NgModelGeneratorBundle\Iterators;

/**
 * Trait UniqueIteratorTrait.
 */
trait UniqueIteratorTrait
{
    /**
     * @var array
     */
    private $seen = [];

    /**
     * @return bool
     */
    public function accept()
    {
        $value = $this->current();

        $key = \is_object($value) ? spl_object_hash($value) : (string) $value;
        if (isset($this->seen[$key])) {
            return false;
        }

        $this->seen[$key] = true;

        return true;
    }

    /**
     * @return mixed
     */
    abstract public function current();
}