Re:^2 Regex to match 20 chars of some digits followed by some spaces

in reply to Re: Regex to match 20 chars of some digits followed by some spaces
in thread Regex to match 20 chars of some digits followed by some spaces

Excellent. Piqued my interest in this approach, which led to a few observations:

you probably want to anchor your match
you could have used dot-star instead of .{0,18}, or you could have specified the chars for the dot (TIMTOWTDI) -- probably the most efficient thing would be to specify (?!\d* +\d), which made me realize...
it can be done with a positive lookahead like so: /^\d(?=\d* *$)[\d ]{19}$/ ("leading digit, followed by digits, then spaces, then end of string, etc.")

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Re: Re:^2 Regex to match 20 chars of some digits followed by some spaces by ysth (Canon) on Dec 21, 2003 at 01:40 UTC
I actually have never used Parse::RecDescent but was assuming it was working on an input buffer using the supplied regex as something like `/\G$regex/gc` so I didn't supply a beginning anchor and an ending anchor is not usable. I haven't got around to checking my assumption yet...and you know what they say when you assUme.	[reply] [d/l]
Re: Re: Re:^2 Regex to match 20 chars of some digits followed by some spaces by ysth (Canon) on Dec 22, 2003 at 09:51 UTC
Well, I've read through Parse::RecDescent and it does work as I had guessed. So solutions to this problem should not have `^` and may not depend on `$`.	[reply] [d/l] [select]

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