ocamllex regex语法错误

Question

我有一些由我的教授编写的基本ocamllex代码，似乎很好：

{ type token = EOF | Word of string }
  rule token = parse
| eof { EOF }
| [’a’-’z’ ’A’-’Z’]+ as word { Word(word) }
| _ { token lexbuf }
    {
     (*module StringMap = BatMap.Make(String) in *)
     let lexbuf = Lexing.from_channel stdin in
     let wordlist =
       let rec next l = match token lexbuf with
         EOF -> l
       | Word(s) -> next (s :: l)
       in next []
     in
     List.iter print_endline wordlist
   }

但是，运行ocamllex wordcount.mll会生成File "wordcount.mll", line 4, character 3: syntax error.

这表明这里第四行正则表达式中的第一个[出现了错误。怎么一回事？

Answer 1

你的文本中似乎有卷曲引号(也叫“智能引号”)。你需要常规的老单引号。

curly quote: ’
old fashioned single quote: '