Re: Hamming minigolf post mortem

On Sat, Apr 19, 2003 at 08:51:45PM +0300, Juho Snellman wrote:
> On Sat, Apr 19, 2003 at 05:29:23PM +0200, Peter Makholm wrote:
> > Daniel Tuijnman <[email protected]> writes: 
> > > I was quite surprised to see such a clean and elegant algorithm as your
> > > 67 post-mortem reach so high. No Perl trickery at all going on here!
> > 
> > I'm surprised to see that we were only two trying to delete exchange
> > <=> for a simple > in the sorting. By the documentation is isn't
> > guaranteed to work but that doesn't usually stop golfers.
> 
> Attempting != succeeding. The > doesn't work reliably when you're
> interested in any elements except the smallest one. I tried >, found
> out that it didn't work, and moved on. Probably others did too.

sort { $a > $b } @list doesn't even work reliably when you're only
interested in the smallest element.  Consider sorting a list containing two
elements, 1 and 3.  The outcome will depend on which value is used as $a
and which as $b.  3 > 1 will return 1, and the result will be (1, 3).  1 >
3, however, will return 0, and the result could be either (1, 3) or (3, 1)!

Any solution which depends on a specific result from such a construct will
almost certainly fail on other implementations of sort.

Ronald