Re: New pattern-matching library (was: str.split with multiple individual split characters)

On Mon, 28 Feb 2011, Guido van Rossum wrote:
> On Mon, Feb 28, 2011 at 8:04 AM, Mike Meyer <mwm-tkOQc4lHIczYtjvyW6yDsg@public.gmane.org> wrote:
>> Possibly we should investigate adding one of those to the standard
>> library, along with a cross-reference from the regexp documentation?
>
> It's been tried before without much success. I think it may have been
> a decade ago that Ka-Ping Yee created a pattern matching library that
> used function calls (and operator overloading? I can't recall) to
> generate patterns -- compiling to re patterns underneath. It didn't
> get much use.

Yes, there was operator overloading.  The expressions looked like this:

     letter + 3*digits + anyspace + either(some(digits), some(letters))

If anyone is curious, the module is available here:

    http://zesty.ca/python/rxb.py

You're welcome to experiment with it, modify it, use it as a starting
point for your own pattern matcher if you like.


--Ping