Re: Zero-width assertions fail with split

De Morgan is kicking your hiney.

It's working as I would expect. You are asking to split on commas that have neither dashes before NOR dashes afterwards, as in "the delimiter is NOT dashes ahead AND a comma AND NOT dashes afterwards". That's the only time the split regex would match. Dashes on either side would prevent the comma from being considered. Your experimental results are borne out.

And simply splitting on commas would give you the list you want, so you'll have to show an example where simply splitting on commas doesn't do it.

-- Randal L. Schwartz, Perl hacker
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Comment on Re: Zero-width assertions fail with split

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Re^2: Zero-width assertions fail with split by Ovid (Cardinal) on Sep 19, 2005 at 05:06 UTC
That makes sense and, as noted, the results aren't entirely suprising, though I confess I struggled with it. Is there some simple way of getting the split behavior to do what I want? Cheers, Ovid New address of my CGI Course.	[reply]
Re^3: Zero-width assertions fail with split by hv (Prior) on Sep 19, 2005 at 12:00 UTC
You want "not both preceded and followed by TOKEN", which is equivalent to "either not preceded by TOKEN, or not followed by TOKEN", and that we can do: `my $split = qr/ (?<!$token) , \| , (?!$token) /x;` [download] Hugo	[reply] [d/l]
Re^3: Zero-width assertions fail with split by gargle (Chaplain) on Sep 19, 2005 at 06:16 UTC
Hi, It may be silly, but, doesn't this do what you want? `perl -e '$a = "1,2,---0---,3,4";@f=split ",",$a;map { print $_."\n"} @f'` [download] -- if ( 1 ) { $postman->ring() for (1..2); }	[reply] [d/l]