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

Paul Moore pf_moore at yahoo.co.uk
Sat Aug 7 21:13:37 CEST 2004

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.

Home computers are being called upon to perform many new functions, including the consumption of homework formerly eaten by the dog -- Doug Larson

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