php-kilo/src/Enum/KeyType.php

<?php declare(strict_types=1);

namespace Aviat\Kilo\Enum;

use Aviat\Kilo\Traits;
use function Aviat\Kilo\ctrl_key;

/**
 * Constants representing various control keys
 */
class KeyType {
	use Traits\ConstList;

	public const ARROW_DOWN = 'ARROW_DOWN';
	public const ARROW_LEFT = 'ARROW_LEFT';
	public const ARROW_RIGHT = 'ARROW_RIGHT';
	public const ARROW_UP = 'ARROW_UP';
	public const BACKSPACE = 'BACKSPACE';
	public const DEL_KEY = 'DELETE';
	public const END_KEY = 'END';
	public const ENTER = 'ENTER';
	public const ESCAPE = 'ESCAPE';
	public const HOME_KEY = 'HOME';
	public const PAGE_DOWN = 'PAGE_DOWN';
	public const PAGE_UP = 'PAGE_UP';

	/**
	 * Returns the ascii character for the specified
	 * ctrl + letter combo
	 *
	 * @param string $char
	 * @return string
	 */
	public static function CTRL(string $char): ?string
	{
		$char = strtolower($char);
		$ord = ord($char);

		// a = 0x61
		// z = 0x7a
		if ($ord >= 0x61 && $ord <= 0x7a)
		{
			return chr(ctrl_key($char));
		}

		// Invalid input, not an ascii letter
		return NULL;
	}
}