Re: [perl #81286] Subsequent assertions with \G and gc modifiersdont work as expected

On Sat, Dec 25, 2010 at 02:26:59PM -0800, Jacob Gelbman wrote:
> # New Ticket Created by  Jacob Gelbman 
> # Please include the string:  [perl #81286]
> # in the subject line of all future correspondence about this issue. 
> # <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=81286 >
> 
> 
> Under Perl 5.12.1, the following test does not succeed.
> 
> use Test::More;
> $_ = "abc";
> ok /\G^/gc;
> ok /\G^/gc; # not ok
> 
> Since you can't be on the "other side" of an assertion, I would expect  
> subsequent regexes to work as the one before them.
> 
> Also, if between the regexes, I put the following, things work as  
> expected:
> 
> pos($_) = pos($_);


I think this comes from not allowing two succesful, zero-length matches
(note you don't need the /c for the behaviour):

    use Test::More;
    $_ = "abc";

    use re 'debug';

    ok /\G^/g;
    ok /\G^/g; # not ok

    done_testing;

    __END__
   Compiling REx "\G^"
   Final program:
      1: GPOS (2)
      2: BOL (3)
      3: END (0)
   stclass END anchored(BOL)(GPOS) GPOS:0 minlen 0 
   Compiling REx "\G^"
   Final program:
      1: GPOS (2)
      2: BOL (3)
      3: END (0)
   stclass END anchored(BOL)(GPOS) GPOS:0 minlen 0 
   Matching REx "\G^" against "abc"
      0 <> <abc>                |  1:GPOS(2)
      0 <> <abc>                |  2:BOL(3)
      0 <> <abc>                |  3:END(0)
   Match successful!
   ok 1
   Matching REx "\G^" against "abc"
      0 <> <abc>                |  1:GPOS(2)
      0 <> <abc>                |  2:BOL(3)
      0 <> <abc>                |  3:END(0)
   Match possible, but length=0 is smaller than requested=1, failing!
   Match failed
   not ok 2
   #   Failed test at /tmp/ss line 15.
   1..2
   # Looks like you failed 1 test of 2.
   Freeing REx: "\G^"
   Freeing REx: "\G^"


I think it's working as intended.


Abigail

• [perl #81286] Subsequent assertions with \G and gc modifiers dont work as expected by Father Chrysostomos via RT
• [perl #81286] Subsequent assertions with \G and gc modifiers dont work as expected by Jacob Gelbman
• Re: [perl #81286] Subsequent assertions with \G and gc modifiersdont work as expected by Abigail