docs: function parseVariable(str, line) {
      var tokens = lexer.read(utils.strip(str)),
        parser,
        out;
  
      parser = new TokenParser(tokens, filters, escape, line, opts.filename);
      out = parser.parse().join('');
  
      if (parser.state.length) {
        utils.throwError('Unable to parse "' + str + '"', line, opts.filename);
      }
  
      /**
       * A parsed variable token.
       * @typedef {object} VarToken
       * @property {function} compile Method for compiling this token.
       */
      return {
        compile: function () {
          return '_output += ' + out + ';\n';
        }
      };
    }