Re: validate variable-length lines in one regex?

You could do something like this:

$s = 'a1 1 2 1.0 1.1 1.2 1.3';;
print grep defined, $s =~ m[([a-z]\d)\s+(\d)\s+(\d)(?:\s+(\d\.\d))?(?:
+\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\
+d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?];;
a1 1 2 1.0 1.1 1.2 1.3

$s = 'a1 1 2 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7';;
print grep defined, $s =~ m[([a-z]\d)\s+(\d)\s+(\d)(?:\s+(\d\.\d))?(?:
+\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\
+d\.\d))?(?:\s+(\d\.\d))?(?:\s+(\d\.\d))?];;
a1 1 2 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7
[download]

Not elegant, but it works.

You'd probably want to generate the regex:

$re = '([a-z]\d)\s+(\d)\s+(\d)' . join '', '(?:\s+(\d\.\d))?' x 10;;
$re = qr"$re";;

$s = 'a1 1 2 1.0 1.1 1.2 1.3';;
print grep defined, $s =~ $re;;
a1 1 2 1.0 1.1 1.2 1.3

$s = 'a1 1 2 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7';;
print grep defined, $s =~ $re;;
a1 1 2 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7
[download]

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

I'm with torvalds on this Agile (and TDD) debunked I told'em LLVM was the way to go. But did they listen!

Comment on Re: validate variable-length lines in one regex? Select or Download Code

Replies are listed 'Best First'.
Re^2: validate variable-length lines in one regex? by uhClem (Scribe) on Jul 06, 2015 at 18:59 UTC
Fun, but hairy. I think for this project I'd just get myself in trouble trying to follow that route.	[reply]
Re^3: validate variable-length lines in one regex? by BrowserUk (Patriarch) on Jul 06, 2015 at 19:20 UTC
I'd just get myself in trouble trying to follow that route. Hm. As you will.	[reply]


Perl: the Markov chain saw
	PerlMonks