code: function lispify(node) {
    if (!('value' in node) && !node.nodes) {
      return '(' + node.type + ')';
    }
    if ('value' in node) {
      return '(' + node.type + ' ' + JSON.stringify(node.value) + ')';
    }
    var buffer = ['(' + node.type];
    node.nodes.forEach(function (childNode, i) {
      buffer.push(' ' + lispify(childNode));
    });
    buffer.push(')');
    return buffer.join('');
  }
docs: /*
  Convert a node to a lisp-like string, useful for debugging rules.
  @param {AstNode|Object} node AST node to lispify.