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    <h3>Editing: NumberConverterInterface.php</h3>
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/**
 * This file is part of the ramsey/uuid library
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @copyright Copyright (c) Ben Ramsey &lt;ben@benramsey.com&gt;
 * @license http://opensource.org/licenses/MIT MIT
 */

declare(strict_types=1);

namespace Ramsey\Uuid\Converter;

/**
 * A number converter converts UUIDs from hexadecimal characters into
 * representations of integers and vice versa
 *
 * @psalm-immutable
 */
interface NumberConverterInterface
{
    /**
     * Converts a hexadecimal number into an string integer representation of
     * the number
     *
     * The integer representation returned is a string representation of the
     * integer, to accommodate unsigned integers greater than PHP_INT_MAX.
     *
     * @param string $hex The hexadecimal string representation to convert
     *
     * @return string String representation of an integer
     *
     * @psalm-return numeric-string
     *
     * @psalm-pure
     */
    public function fromHex(string $hex): string;

    /**
     * Converts a string integer representation into a hexadecimal string
     * representation of the number
     *
     * @param string $number A string integer representation to convert; this
     *     must be a numeric string to accommodate unsigned integers greater
     *     than PHP_INT_MAX.
     *
     * @return string Hexadecimal string
     *
     * @psalm-return non-empty-string
     *
     * @psalm-pure
     */
    public function toHex(string $number): string;
}
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