This doesn't work, because of the (documented in perlop) magic comparison with $. when the conditions are constants:

Fix: 

perl -lwe'$true=1; print for grep $true../D/, qw(A B C D E F)'

[download]

Note that it will flip for "E" (like your last version). What you probably intended is: 

perl -lwe'my @a=qw(A B C D E F); print for grep ($_==1) .. ($a[$_]=~/D
+/), 0..$#a'

[download]

Or without a flip-flop: 

perl -lwe'for (qw( A B C D E F )) { print; last if /D/ }'

[download]

In reply to Re: Flip-flop won't DWIM by ikegami
in thread Flip-flop won't DWIM by wu-lee

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