Re^4: Zero-width look-ahead regexp question

"it is surprising how a glass of Italian Chardonnay can do good to the brain cells"

But it is far from surprising that providing a clear specification of what you seek will enhance the liklihood that the Monks will provide useful advice.

I mention this because your original post. The first bit of code, [/^(BAR|BAZ)$/, requires that /BA[RZ]/ NOT be the last element of your string, while the second, the negative lookahead, (?!(BAR|BAZ)).*$/, allows anything NOT /BA[RZ]/ followed by (your dot_deathstar, .* any number of any characters INCLUDING /BA[RZ]/.

Judging by other replies, I wasn't the only one confounded thereby. yet very shortly after your clarifying example (in this node's parent) you got a reasonably general answer from Anonymonk (and re that answer, I'm not sure I buy the advice to "avoid as the plague the use of capturing groups in the decomposed regexes..." but the thought process outlined in that node deserves a ++ ((and got same from me)).

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Re^5: Zero-width look-ahead regexp question by rovf (Priest) on Jul 02, 2008 at 07:02 UTC
while the second `[...]` allows anything NOT /BARZ/ followed by (your dot_deathstar, . any number of any characters INCLUDING /BARZ/* That's why I had added but of course this is not quite right, since it would also reject FOOBARX, but you are right that I should have been much more clear in my OP. I had included the (wrong) approach so that you don't believe I would just ask for help without at least trying to solve it on my own, but in the way I did it, it just caused a lot of confusion.... -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]

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Re^5: Zero-width look-ahead regexp question
by rovf (Priest) on Jul 02, 2008 at 07:02 UTC

while the second [...] allows anything NOT /BARZ/ followed by (your dot_deathstar, .* any number of any characters INCLUDING /BARZ/

That's why I had added but of course this is not quite right, since it would also reject FOOBARX, but you are right that I should have been much more clear in my OP. I had included the (wrong) approach so that you don't believe I would just ask for help without at least trying to solve it on my own, but in the way I did it, it just caused a lot of confusion....

--
Ronald Fischer <ynnor@mm.st>

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