_wp_to_kebab_case

_wp_to_kebab_case: 这个函数将一个字符串转换为kebab大小写格式（小写的连字符而不是空格）。它用于将lug或taxonomy名称转换为URL友好格式。

这个函数试图复制lodash的kebabCase（JS库）在客户端的作用。

我们需要这个函数的原因是，我们在客户端和服务器中都做了一些处理（例如：我们从预设的slug中生成预设的类），需要创建相同的输出。

由于向后兼容，我们不能删除或更新客户端的库（lodash的kebabCase的一些输出被保存在文章内容中）。我们必须使服务器的行为与客户端一样。

对这个函数的修改应该跟随客户端的更新，其逻辑也是一样的。

function _wp_to_kebab_case( $string ) {
	//phpcs:disable WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase
	// ignore the camelCase names for variables so the names are the same as lodash
	// so comparing and porting new changes is easier.

	/*
	 * Some notable things we've removed compared to the lodash version are:
	 *
	 * - non-alphanumeric characters: rsAstralRange, rsEmoji, etc
	 * - the groups that processed the apostrophe, as it's removed before passing the string to preg_match: rsApos, rsOptContrLower, and rsOptContrUpper
	 *
	 */

	/** Used to compose unicode character classes. */
	$rsLowerRange       = 'a-z\xdf-\xf6\xf8-\xff';
	$rsNonCharRange     = '\x00-\x2f\x3a-\x40\x5b-\x60\x7b-\xbf';
	$rsPunctuationRange = '\x{2000}-\x{206f}';
	$rsSpaceRange       = ' \t\x0b\f\xa0\x{feff}\n\r\x{2028}\x{2029}\x{1680}\x{180e}\x{2000}\x{2001}\x{2002}\x{2003}\x{2004}\x{2005}\x{2006}\x{2007}\x{2008}\x{2009}\x{200a}\x{202f}\x{205f}\x{3000}';
	$rsUpperRange       = 'A-Z\xc0-\xd6\xd8-\xde';
	$rsBreakRange       = $rsNonCharRange . $rsPunctuationRange . $rsSpaceRange;

	/** Used to compose unicode capture groups. */
	$rsBreak  = '[' . $rsBreakRange . ']';
	$rsDigits = '\d+'; // The last lodash version in GitHub uses a single digit here and expands it when in use.
	$rsLower  = '[' . $rsLowerRange . ']';
	$rsMisc   = '[^' . $rsBreakRange . $rsDigits . $rsLowerRange . $rsUpperRange . ']';
	$rsUpper  = '[' . $rsUpperRange . ']';

	/** Used to compose unicode regexes. */
	$rsMiscLower = '(?:' . $rsLower . '|' . $rsMisc . ')';
	$rsMiscUpper = '(?:' . $rsUpper . '|' . $rsMisc . ')';
	$rsOrdLower  = '\d*(?:1st|2nd|3rd|(?![123])\dth)(?=\b|[A-Z_])';
	$rsOrdUpper  = '\d*(?:1ST|2ND|3RD|(?![123])\dTH)(?=\b|[a-z_])';

	$regexp = '/' . implode(
		'|',
		array(
			$rsUpper . '?' . $rsLower . '+' . '(?=' . implode( '|', array( $rsBreak, $rsUpper, '$' ) ) . ')',
			$rsMiscUpper . '+' . '(?=' . implode( '|', array( $rsBreak, $rsUpper . $rsMiscLower, '$' ) ) . ')',
			$rsUpper . '?' . $rsMiscLower . '+',
			$rsUpper . '+',
			$rsOrdUpper,
			$rsOrdLower,
			$rsDigits,
		)
	) . '/u';

	preg_match_all( $regexp, str_replace( "'", '', $string ), $matches );
	return strtolower( implode( '-', $matches[0] ) );
	//phpcs:enable WordPress.NamingConventions.ValidVariableName.VariableNotSnakeCase
}