Re: Regex to match ascending sequence

This works for me

 
my $regex = qr# (\d) (??{ my $c //= $1 ; ++$c })+ #x;

"2345654321" =~ $regex;

print $&;
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language and ☆☆☆☆ :)

Je suis Charlie!}

Comment on Re: Regex to match ascending sequence Download Code

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Re^2: Regex to match ascending sequence by ExReg (Priest) on Oct 15, 2015 at 17:27 UTC
Unfortunately, when I try this on my Perl 5.8, I get a panic: top_env message. I know that it doesn't have the //= operator.	[reply]
Re^3: Regex to match ascending sequence by Laurent_R (Canon) on Oct 15, 2015 at 22:31 UTC
`$c //= $d;` [download] is just syntactic sugar for various constructs such as: `$c = defined $c ? $c : $d;` [download] or `$c = $d unless defined $c;` [download] Update: I've just quickly tried on an old VMS platform with Perl 5.8.6 with this regex definition: `$regex = qr# (\d) (??{ my $c = $1 unless defined $c; ++$c })+ #x;` [download] it still does not seem to work.	[reply] [d/l] [select]
Re^3: Regex to match ascending sequence by LanX (Saint) on Oct 15, 2015 at 18:14 UTC
The Defined-Or operator is best emulated with `defined` and `or` No idea about scopes in 5.8 , I remember 5.10 (or 5.12 ?) having an issue in this case. Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!}	[reply]
Re^3: Regex to match ascending sequence by Anonymous Monk on Oct 15, 2015 at 17:30 UTC
Try `local our $c;` Also, 5.8 is too old for experimental regex features	[reply] [d/l]
Re^4: Regex to match ascending sequence by ExReg (Priest) on Oct 15, 2015 at 17:38 UTC
The local our did not help. You are right about it being too old. Wish it was newer.	[reply]