/**
 * 给一组指定的关键词添加span标签，高亮突出显示关键词
 * Example use: $spanned = codeWords($string_containing_keywords);
 * Using colour==blue,but different arrays of words and different 
 * colours can be added.
 * @param 
 * @author 网： www.512Pic.com
 **/

function onlyWholeWords(&$value,$key) {
	// Ignores words after // comment delimiters.
	//$value = "/\b(" . $value . ")\b/";    // doesn't handle comments
	//$value = "/^(?:(?!\/\/).)*\K\b(" . $value . ")\b/"; 
	// \K lookbehind alternative is not supported in PHP < 5.2.4,so use:
	$value = "/^((?:(?!\/\/).)*)\b" . $value . "\b/";
}
function addSpan(&$value,$key,$color='blue') {
	$value = "$1<span style='color:$color'>" . $value . "</span>";
}
function codeWords($code) {
	$keywords = array('as','break','case','class','continue','default','do','elif','else','elseif','for','foreach','function','if','new','null','return','self','switch','this','to','typeof','until','var','void','while','with');
	$keywords2 = $keywords;
	array_walk($keywords,'onlyWholeWords');
	array_walk($keywords2,'addSpan','blue');
	$code = preg_replace($keywords,$keywords2,$code);
	return $code;
}


/***   来自编程之家 jb51.cc（jb51.cc）   ***/