ocamllex regex语法错误

问题描述

我有一些基本的ocamllex代码，由我的教授编写，似乎还不错:

I have some basic ocamllex code, which was written by my professor, and seems to be fine:

{ 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会产生File "wordcount.mll", line 4, character 3: syntax error.

这表示此处第四行的正则表达式的第一个[处有错误.发生了什么事?

This indicates that there is an error at the first [ in the regex in the fourth line here. What is going on?

推荐答案

您的文本中似乎带有卷曲的引号(也称为智能引号"-ugh).您需要常规的旧单引号.

You seem to have curly quotes (also called "smart quotes" -- ugh) in your text. You need regular old single quotes.

curly quote: ’
old fashioned single quote: '

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