[Python-Dev] Re: pre-PEP: Complete, Structured Regular Expression Group Matching (original) (raw)

Mike Coleman mkc at mathdogs.com
Sat Aug 7 19:46:10 CEST 2004

Paul Moore <pf_moore at yahoo.co.uk> writes:

I was interested in your message as a break from @decorators, but I couldn't muster the energy to think about the proposal because I've been reading too many @decorator messages. I guess you won one way and lost the other :-)

@:-)

Maybe a better name would be re.parse? The function has a "feel" of parsing a string according to a pattern.

This is a nice suggestion. The main objection I can think of is that we might be stealing that name from some future idea that would more deserve it.

The only other comment I have is that the semantics seem pretty complex - I think that in practice, they do more or less what you want them to, but the description is pretty obscure.

Yeah, probably the doc will need to be carefully written, with good examples, to make this go down easily. I hope that for practical cases it'll be relatively straightforward.

And although I can see that the error return has some value, I suspect that it might actually complicate real use.

Someone else suggested throwing an exception instead, which I'm now leaning in favor of, too.

A suggestion - would it be possible to implement re.structmatch as a pure Python prototype, to thrash out some of the usability questions? If the function appears valuable in such a form, arguing for incorporation into the re module would be a lot easier.

I suspect that in this case a pure Python implementation might actually be a lot harder than implementing it as a C patch. This is because so much of the work is already done in the current re module; the C patch would probably not be that big. In order to do it in Python I'd end up reimplementing re.match in Python, which I wouldn't look forward to.

It's because of this that I'm trying to get as much preliminary comment as I can.

Cheers, Mike

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