in reply to Re^4: [bugs?] perldoc perlre, \G and pos()
in thread [bugs?] perldoc perlre, \G and pos()

1st Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
2nd Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
3rd Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
...

  • Comment on Re^5: [bugs?] perldoc perlre, \G and pos()

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Re^6: [bugs?] perldoc perlre, \G and pos()
by LanX (Saint) on Sep 29, 2009 at 15:35 UTC
    while() puts scalar context, so just _one_ try to match, and no match results in false!

    ...no repeated matches like in list context.

    Cheers Rolf

[reply]

      You clearly see that it does match, so why do you keep saying it doesn't match in response to my explanation?

      1st Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
      2nd Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
      3rd Pass: It thinks it hasn't matched yet because pos == 0, so it matches, setting pos = 0.
      ...

      ...no repeated matches like in list context.

      The while isn't there for decoration. It's the one doing the repeating.

[reply]
[d/l]
        you still haven't looked at the code I posted. With pos==0 it doesn't match, but there are two different kind of undefined pos (one after the variable is initialized, and one after the first match) which is evidently a bug!

          DB<168> $str="abcd"
 
  DB<169> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<170> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
0::
  DB<171> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<172> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<173> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<174> pos($str)=0
 
  DB<175> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
0::
  DB<176> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<177> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<178> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<179> pos($str)=undef
 
  DB<180> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<181> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:
  DB<182> print pos($str),":",scalar ($str=~/(.)\G/g),":",$1
:1:

        [download]

        Cheers Rolf

[reply]
[d/l]

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