Beefy Boxes and Bandwidth Generously Provided by pair Networks
laziness, impatience, and hubris
 
PerlMonks  

Re^4: how to split the string into two or three numbers based on certain value.

by AnomalousMonk (Monsignor)
on Feb 12, 2013 at 15:41 UTC ( #1018397=note: print w/ replies, xml ) Need Help??


in reply to Re^3: how to split the string into two or three numbers based on certain value.
in thread how to split the string into two or three numbers based on certain value.

Can you explain me the regulsr expression ...

I can begin to explain it and then pass you off to some explanations in the docs that do a better job than I could.

  •  \G   Begin a 'global' search (i.e., a search controlled by the  /g regex modifier) at the exact position where the previous search left off, or at the start of the string (same as \A) if there was no previous search.
  •  (\d{2,3}?)   Capture two or three decimal digits. Because the  ? 'lazy' match modifier controls matching, try first to capture two digits (normal matching would be 'greedy' and try to grab three).
  •  (?(?{ $^N < 32 }) (*FAIL))   If the two digits captured by the immediately previous capture group (see  $^N   in perlvar) are numerically less than 32, fail that match and go back and try for three digits. Here's where I bail out. See Extended Patterns in perlre and search for the "(?(condition)yes-pattern)" discussion; also check the Conditional expressions section in perlretut. Check Special Backtracking Control Verbs in perlre for info on (*FAIL); see also the Backtracking control verbs discussion in perlretut. (Note that  (*FAIL) can be replaced by  (?!) if you're scared by the "WARNING: These patterns are experimental and subject to change..." language prefacing documentation of these verbs.)
HTH.


Comment on Re^4: how to split the string into two or three numbers based on certain value.
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1018397]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (18)
As of 2014-08-27 14:59 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The best computer themed movie is:











    Results (242 votes), past polls