Re: [FWP] Golf (7, er 16 strokes is par!)

[Ronald J Kimball <rjk@linguist.dartmouth.edu>]

On Tue, May 02, 2000 at 06:17:10PM +0300, Ariel Scolnicov wrote:
> Bennett Todd <bet@rahul.net> writes:
> 
> > Well, if you have
> > 
> > 	print "$_ is a power of two\n" unless $_&$_-1;
> > 
> > and you want to toggle the value if $_==0, how about
> > 
> > 	print "$_ is a power of two\n" if !$_^!($_&$_-1);
> 
> At the cost of making the code clearer, you could ignore the value
> when $_ == 0, just say:
> 
>      print "$_ is a power of two\n" if $_&&($_&$_-1);
> 
> and save another character.

That's equivalent to the original 7-character code, and your logic is
backwards.


> > which comes to 14 if I count right. Sure is a shame that there isn't
> > a ^^ operator, which like && and || would treat its args as booleans
> > rather than bitstrings. They could have done that when they
> > introduced xor, but as best I can tell they didn't.
> 
> Short-circuit XOR operator?  Is that like the "electricity powder" we'd 
> send people to get from the technical stores in the Army, so we could
> fix flat batteries?

Note that he never said 'short-circuit'.  He said 'boolean'.  C<and> and
C<or> short-circuit, but C<xor> doesn't (of course).  C<^^> could be the
same.


Ronald

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