code: function pushTextNode(text) {
          switch (options.trimWhitespace) {
              case 'blank':
                  if (/^\s+$/.test(text)) {
                      text = null;
                  }
                  break;
  
              case 'all':
                  text = text.replace(/(^\s+|\s+$)/g, '');
                  break;
          }
  
          if (text) {
              currentNode.children.push({
                  textExpr: parseText(text, options.delimiters)
              });
          }
      }
docs: 在读取栈中添加文本节点
  
  @inner
  @param {string} text 文本内容