Re: Flip-flop won't DWIM

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Re^2: Flip-flop won't DWIM by Roy Johnson (Monsignor) on May 21, 2009 at 20:30 UTC
So use the match-once operator (no need for an actual pattern; the empty pattern works fine): `print join ' ', grep scalar(??../D/), ('A'..'F');` [download] Caution: Contents may have been coded under pressure.	[reply] [d/l]
Re^3: Flip-flop won't DWIM by wu-lee (Beadle) on May 22, 2009 at 10:54 UTC
Aha! Finally, a use for the match-once operator! And it seems to be tailor made for this problem. Bravo!	[reply]
Re^2: Flip-flop won't DWIM by akho (Hermit) on May 21, 2009 at 15:57 UTC
Also: List::MoreUtils is your friend.	[reply]
Re^3: Flip-flop won't DWIM by wu-lee (Beadle) on May 21, 2009 at 16:03 UTC
Yes. However, List::MoreUtils is not in core, so it's not something I want to rely on in the current circumstance.	[reply]
Re^2: Flip-flop won't DWIM by wu-lee (Beadle) on May 21, 2009 at 15:58 UTC
Right. Of course, silly me. Ok, so this does what I want: `perl -lwe '$x = 1; print join " ", grep { scalar($x++../D/) } qw(A B C + D E F)' # prints: # A B C D` [download] Although this is not particularly neat. Is there a better way?	[reply] [d/l]
Re^3: Flip-flop won't DWIM by akho (Hermit) on May 21, 2009 at 16:15 UTC
Your code prints "A B C D E F" for me, and I cannot see why it would print anything else. This seems to work if you insist on using flip-flop: `$x = 1; print join " ", grep { $x..(($x=0) or /D/) } qw(A B C D E F);` [download] However, you could copy stuff from List::MoreUtils.	[reply] [d/l]
Re^3: Flip-flop won't DWIM by wu-lee (Beadle) on May 21, 2009 at 16:13 UTC
Actually, that doesn't, but this does: `perl -lwe '$x = 0; print join " ", grep { scalar(!$x++../D/) } qw(A B + C D E F)' # prints: # A B C D` [download]	[reply] [d/l]
Re^3: Flip-flop won't DWIM by ikegami (Patriarch) on May 21, 2009 at 16:57 UTC
The "++" does nothing.	[reply]