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[Caml-list] Resource acquisition is initialization
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Date: -- (:)
From: Xavier Leroy <xavier.leroy@i...>
Subject: Re: [Caml-list] Resource acquisition is initialization
> Maybe I don't understand something but IMHO it's not very usable because
> with_file_in type is fixed after the first use. So e.g. input_line and
> input_char operation cannot be mixed. You cannot write something like
> 
> let process filename =
>   let f = with_file_in filename in
>      begin
>        print_string (f input_line);
>        print_char   (f input_char); (* syntax error! *)
>      end

Even without the typing problem, this would open and close the file
twice, which isn't what you want.  The correct usage is:

let process filename =
  with_file_in filename
    (fun ic ->
       print_string (input_line ic);
       print_char (input_char ic))

- Xavier Leroy
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