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

[Paul Moore]

Mike Coleman <mkc at mathdogs.com> writes:

> 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.

Fairy nuff. I was assuming (on no particular basis - you've obviously
looked into this in a lot more detail than me) that you could
implement it using re.match - but on reflection, I can see that this
would probably not be true.

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

That's reasonable. As I said before, I have a tendency to avoid the re
module too much (a perfect recent example was some code I wrote
splitting a string on a ":" character, then laboriously trimming each
part - I really should have done re.split on \s*:\s*). On that basis,
your examples give me a mixed reaction - the results impress me with
the ability to get exactly the right information out in a single
parse, but the regular expressions needed look utterly unmaintainable.

I suppose I'm saying that if I liked re's, I'd love this feature. As
it is, it leaves me looking for the same feature but with a better
pattern syntax.

But your examples reinforce for me that "parse" is a reasonable name
for the method.

Paul.
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