docs: function() {
      var captures;
      if (captures = /^(?:block +)?prepend +([^\n]+)/.exec(this.input)) {
        var name = captures[1].trim();
        var comment = '';
        if (name.indexOf('//') !== -1) {
          comment = '//' + name.split('//').slice(1).join('//');
          name = name.split('//')[0].trim();
        }
        if (!name) return;
        this.consume(captures[0].length - comment.length);
        var tok = this.tok('block', name);
        tok.mode = 'prepend';
        this.tokens.push(tok);
        return true;
      }
    }