Regex Selector for jQuery - James Padolsey

jquery.regex-selector.js

jQuery.expr[':'].regex = function(elem, index, match) {
    var matchParams = match[3].split(','),
        validLabels = /^(data|css):/,
        attr = {
            method: matchParams[0].match(validLabels) ? 
                        matchParams[0].split(':')[0] : 'attr',
            property: matchParams.shift().replace(validLabels,'')
        },
        regexFlags = 'ig',
        regex = new RegExp(matchParams.join('').replace(/^\s+|\s+$/g,''), regexFlags);
    return regex.test(jQuery(elem)[attr.method](attr.property));
}

I don't understand.
What is the large code snippet at the top? Do I put that into my js so that these lines from the Usage will work? I tried this, and I got

SyntaxError: syntax error
method: matchParams[].match(validLabels) ?

Help appreciated. Thanks

@KevinDrew

http://james.padolsey.com/javascript/regex-selector-for-jquery/

jQuery.expr[':'].regex = function(elem, index, match) {
    var matchParams = match[3].split(','),
        validLabels = /^(data|css):/,
        attr = {
            method: matchParams[0].match(validLabels) ? 
                        matchParams[0].split(':')[0] : 'attr',
            property: matchParams.shift().replace(validLabels,'')
        },
        regexFlags = 'ig',
        regex = new RegExp(matchParams.join('').replace(/^\s+|\s+$/g,''), regexFlags);
    return regex.test(jQuery(elem)[attr.method](attr.property));
}

You have error at this line:

regex = new RegExp(matchParams.join('').replace(/^s+|s+$/g,''), regexFlags);

Do not forget backslash before 's'