Re: Regex to match ascending sequence

What did you expect $c++ to do, knowing that the first time the code is run the value of $c is the current regular expression ?

Anyway, here is something that should do what you want:

'234565432' =~ / 
  (\d) (?{ $c = $1}) # Match the first number and initialize $c
  (?:
    (??{ ++$c })     # Same as the previous char + 1
  )*/x;

print $&;
[download]

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 17:19 UTC
Saints be praised! OK, maybe Curates be praised! It works. And it makes sense. Can't beat that. I can feel scales of ignorance falling off my eyes as I type.	[reply]
Re^2: Regex to match ascending sequence by Anonymous Monk on Oct 15, 2015 at 17:24 UTC
Try 148012 :)	[reply]
Re^3: Regex to match ascending sequence by LanX (Saint) on Oct 15, 2015 at 22:45 UTC
> Try 148012 :) This should do `my $regex = qr/ \d (??{ substr($&, -1) + 1 }) + /x; "148012" =~ $regex; print ">$&<" __END__ >012<` [download] The minimal length of the sequence can be set by `{x,}` instead of the `+` quantifier. š Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!} š) with x = min-1	[reply] [d/l] [select]
Re^4: Regex to match ascending sequence by ExReg (Priest) on Oct 16, 2015 at 14:41 UTC
Beautiful. I substituted the {x,} in for the + as you suggested and it worked on longer sequences. These will go a long way to help me understand how to construct dynamic regexes.	[reply]
Re^5: Regex to match ascending sequence by LanX (Saint) on Oct 16, 2015 at 18:19 UTC
Re^3: Regex to match ascending sequence by ExReg (Priest) on Oct 15, 2015 at 17:35 UTC
I think that it is to be expected with left-most, longest. It would find the 1, not find a 2 after it and quit, without seeing that there is a 012 later.	[reply]