[plt-scheme] "raw" strings

From: Todd O'Bryan (toddobryan at gmail.com)
Date: Fri Sep 18 20:51:21 EDT 2009

Oh, cool. Thanks!

On Fri, Sep 18, 2009 at 7:51 PM, Sam TH <samth at ccs.neu.edu> wrote:
> On Fri, Sep 18, 2009 at 7:21 PM, Todd O'Bryan <toddobryan at gmail.com> wrote:
>> I hate to ask this, given how much I've been burned by mentioning
>> experience with Python before, but...
>>
>> One of my favorite features of Python is the fact that you can delimit
>> strings with either " or '. That way, you can enclose strings that
>> have double-quotes in apostrophes and strings that have apostrophes in
>> double-quotes.
>>
>> Clearly, this won't work with Scheme because of symbols, but another
>> really nice feature of Python is the "raw" string, which is especially
>> useful in things like regular expressions. Basically, a raw string
>> (with the letter 'r' prepended to the front of the first quote)
>> doesn't treat a backslash as a meta-character.
>>
>> So, if I want to match strings like 455 \ 22, 127 \ 31, or 3 \
>> 5--corresponding to the regex \d+\s\\\s\d+, instead of typing
>>
>> "\\d+\\s\\\\\\s\\d+"
>>
>> I'd type
>>
>> r"\d+\s\\\s\d+"
>>
>> which is ever so much more readable.
>>
>> Since PLT already has #rx"patt" and #px"patt" patterns, how hard would
>> it be to create a version that lets you avoid the insane amounts of
>> backslash escaping?
>
> How about
>
> #lang at-exp scheme
> (define r @regexp{\d+\s\\\s\d+})
>
> --
> sam th
> samth at ccs.neu.edu
>


Posted on the users mailing list.