jQuery alterClass plugin: Remove element classes with wildcard matching. Optionally add classes.

jquery.alterclass.js

/**
 * jQuery alterClass plugin
 *
 * Remove element classes with wildcard matching. Optionally add classes:
 *   $( '#foo' ).alterClass( 'foo-* bar-*', 'foobar' )
 *
 * Copyright (c) 2011 Pete Boere (the-echoplex.net)
 * Updated 2013 by Mike Pouncy (scrupl.es) - Condensed code, removed unneeded vars.
 * Free under terms of the MIT license: http://www.opensource.org/licenses/mit-license.php
 *
 */
;(function ( $ ) {

    $.fn.alterClass = function jQueryAlterClass( removals, additions ) {

        if ( removals.indexOf( '*' ) === -1 ) {
            // Use native jQuery methods if there is no wild-card matching
            this.removeClass( removals );
        } else {
            var pattern = new RegExp( '\\s'
                + removals
                    .replace( /\*/g, '[A-Za-z0-9-_]+' )
                    .split( ' ' )
                    .join( '\\s|\\s' )
                + '\\s', 'g' );

            this.each( function forEachAlteredClass( i, it ) {
                for ( var cn = ' ' + it.className + ' '; pattern.test( cn ); ) {
                    cn = cn.replace( pattern, ' ' );
                }
                it.className = $.trim( cn );
            });
        }

        return( additions ? this.addClass( additions ) : this );
    };

})( jQuery );

Condensed code, removed unneeded vars.