You can keep track of it's state by storing its return value. If the last return value was false or =~/E/, it will look for the first regex on the next iteration; otherwise it will look for the second.

A quick test: 

$ perl -we'sub makeit { my $i; sub { ++$i; ($i%6==1)..($i%6==3) } }
$z = makeit(); $y = makeit(); print grep {&$y; &$z} "a".."r"'
abcghimno

[download]
shows that multiple closures made from the same anonymous sub have different states. The &$y call has no effect on &$z's return value.

It is likely to be possible to save (and with 5.8.1, restore) a flipflop's state using the B module.

In reply to Re: State information for flipflop .. operator. by ysth
in thread State information for flipflop .. operator. by rinceWind

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