正規表現による置換の練習

/**
 * Copyright mezumona ( http://wonderfl.net/user/mezumona )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/2SF0
 */

package {
    import flash.display.Sprite;
    import flash.display.DisplayObjectContainer;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;

    public class FlashTest extends Sprite
    {
        public function FlashTest()
        {
            initializeTrace(this);

            var source:String = "#hoge=10\n"
             + ";comment\n"
             + "    piyo=mogera\t \t#foo\n\n"
             + "bar#\n"
             + "42";
            trace("----");
            trace("source :");
            trace("----");
            trace(source);

            trace("----");
            trace("/^[ \\t]*(([#;].*)?\\n)?|[ \\t]*(#.*$)/mg → '' :");
            trace("----");
            var cutted:String
             = source.replace(/^[ \t]*(([#;].*)?\n)?|[ \t]*(#.*$)/mg, "");
            trace(cutted);
            
        }

        private var tf_:TextField = new TextField();
        public function trace(...rest):void
        {
            tf_.appendText(rest.join(" "));
            tf_.appendText("\n");
        }

        public function initializeTrace(target:DisplayObjectContainer):void
        {
            tf_.autoSize = TextFieldAutoSize.LEFT;
            target.addChild(tf_);
        }

    }
}