Re: regexp hell

["B. T. Raven" <btraven@nihilo.net>]

> On 28/12/2012 10:57, B. T. Raven wrote:
> 
>> I am trying to byte-compile my .emacs for the first time and I see the
>> complaint "replace-string is to be used interactively..." or something.
>> I am using the form:
>>
>>   (replace-string "\\" "\\\\" nil (point-min) (point-max))
>>
>> in a function and it seems to work but I can't make any equivalent re's
>> work in re-search-forward (the suggested equivalent  to be used in a
>> lisp programm). I can't get past the "trailing backslash" error. Is
>> there something kosher for the above replace-string form?
>>
>> Thanks,
>>
>> Ed
>>
> 
> You can use `search-forward' (which searches for string, not for regexp),
> as it is suggested in documentation for `replace-string':
> 
>   (while (search-forward FROM-STRING nil t)
>     (replace-match TO-STRING nil t))
> 
> Then with the above strings it should replace one backslash with two.

Thanks, Filipp. That's what I needed. Now the .emacs byte-compiles
without issuing a warning.


> 
> But if you still need to write a regexp, it seems that you need to
> double the amount of backslashes. To include a backslash in a regexp you
> need to prefix it with another backslash and each backslash should be
> prefixed with another one when written in a lisp program (so, 4
> backslashes in a program for a single one in regexp).
>