wikimedia/mediawiki-extensions-Wikibase

<?php

declare( strict_types = 1 );

namespace Wikibase\Repo;

use Traversable;

/**
 * Lazy and potentially infinite version of PHPs native range() function (without $step support).
 *
 * @license GPL-2.0-or-later
 */
class RangeTraversable implements \IteratorAggregate {

    /** @var int */
    private $startingNumber;
    /** @var int|null */
    private $inclusiveUpperBound;

    public function __construct( int $startingNumber = 1, int $inclusiveUpperBound = null ) {
        $this->startingNumber = $startingNumber;
        $this->inclusiveUpperBound = $inclusiveUpperBound;
    }

    public function getIterator(): Traversable {
        $number = $this->startingNumber;

        if ( $this->inclusiveUpperBound === null ) {
            // @phan-suppress-next-line PhanInfiniteLoop
            while ( true ) {
                yield $number++;
            }
        } else {
            while ( $number <= $this->inclusiveUpperBound ) {
                yield $number++;
            }
        }
    }

}