docs: function compile_fancy(block, scope) {
      var fns= block.toString().replace(css_matcher, function(src, tag_name, classes, hash, empty){
        var result= src.replace(classes, ''), tag_start,
            class_names= (classes || "").split(' ').join('').split('.').splice(1).join(' ');
        if(!tagset[tag_name]) {
          result= src;
        } else if(class_names !== "") {
          tag_start= tag_name +'({"class":"'+ class_names +'"';
          if(hash) {
            result= tag_start +', '+ result.substring((result.indexOf('{') + 1));
          } else if(empty) {
            result= tag_start +'})';
          } else {
            result= tag_start +'},'+ result.substring((result.indexOf('(') + 1));
          }
        } 
        return result;
      });
      return compile_scope(fns, scope);
    }