全部答案

2013-10-09 18:50:25

• lists模块的操作,看到flatten的操作不是很理解,所以查了查,看到一个不错的帖子,学习学习 (转)关键技术点: erlang中string 就是list

  全部
  

  C***

  2013-10-09 18:50:25

  125 69 评论

  分享
  提交评论
2013-10-09 18:49:58

•   erlang中string 就是list，所以没有list_to_string或string_to_list的函数，但是，对于借助erlydtl生成的如下脚本：
  ["/ntotal ","1"," page num is/n/n  colName1colName2/n  ",[["/n  /n  ","22384814347478301","/n  ",['list8888','test8888'],"/n  /n  "],["/n  /n  ","12384814347478301","/n  ",['list9999','test9999'],"/n  /n  "]],"/n/n/n"]
  erlang自带的 inets是无法解析的，我们需要去掉除最外的"[“和 ”]"之外的所有"[" "]"，通过lists:flatten()可以去掉。
    但是，前提是每个ListofList的元素不能是atom，比如：上面的html，如果直接
  lists:flatten(["/ntotal ","1"," page num is/n/n  colName1colName2/n  ",[["/n  /n  ","22384814347478301","/n  ",['list8888','test8888'],"/n  /n  "],["/n  /n  ","12384814347478301","/n  ",['list9999','test9999'],"/n  /n  "]],"/n/n/n"])。
    
  结果是：
  [60,99,101,110,116,101,114,62,10,60,104,50,62,116,111,116,
   97,108,32,49,32,112,97,103,101,32,110,117,109|。。。]
   
  如果将['list8888','test8888']换成 “['list8888','test8888']”或者["list8888","test8888"]就可以了
  eg:
  1）lists:flatten(["/ntotal ","1"," page num is/n/n  colName1colName2/n  ",[["/n  /n  ","22384814347478301","/n  ",["list8888","test8888"],"/n  /n  "],["/n  /n  ","12384814347478301","/n  ",["list9999","test9999"],"/n  /n  "]],"/n/n/n"])。
    
  结果：
  "/ntotal 1 page num is/n/n  colName1colName2/n  /n  /n  22384814347478301/n  list8888test8888/n  /n  /n  /n  12384814347478301/n  list9999test9999/n  /n  /n/n/n"
  2）lists:flatten(["/ntotal ","1"," page num is/n/n  colName1colName2/n  ",[["/n  /n  ","22384814347478301","/n  ","['list8888','test8888']","/n  /n  "],["/n  /n  ","12384814347478301","/n  ","['list9999','test9999']","/n  /n  "]],"/n/n/n"])。
    
  结果：
  "/ntotal 1 page num is/n/n  colName1colName2/n  /n  /n  22384814347478301/n  ['list8888','test8888']/n  /n  /n  /n  12384814347478301/n  ['list9999','test9999']/n  /n  /n/n/n"
   （下面的操作很犀利！）
  所以现在的问题是如何实现在 一个tuple或者一个list的前后加上 双引号(""),方法如下：
  用lists:flatten(io_lib:write或lists:flatten(io_lib:format("~p"。
    。。来实现，
  eg:
  1）List1=[aaa,bbb]。
  lists:flatten(io_lib:write(List1))。
  结果：
  "[aaa,bbb]"
   
  2）lists:flatten(io_lib:format("~p",[List1]))。
    
  结果：
  "[aaa,bbb]"
   
  注意：format的第一个参数用~p可以用多行显示，比~w更能保持变量的原样，第二个参数一定要是List，所以要用"[]"将变量扩起来，（亲，记得点击下方【好评】哦，您的好评是我最大的动力，么么哒~)。
    

  全部
  

  阿***

  2013-10-09 18:49:58

  136 66 评论

  分享
  提交评论