Which is exactly why I offered it as a golfed version only - but I probably should have mentioned that lest someone use the golfed version in production code. Hopefully you've saved someone a world of trouble.

Being an old C programmer, I was taught never to trust the order of evaluation of parameters (right to left, left to right or something in between). But it does seem to work consistently on my version of Perl (5.8.8) - raising the question: does Perl have a defined order of evaluation for parameters or is it like "other languages" and leaves order to the optimizer and compiler implementation? I looked for a citation either way this AM and had no luck.

Best, beth

In golf you still have to get the ball in the hole generate the correct result. Bugs in golfed Perl are still bugs. ;)

In the second paragraph of the Auto increment and Auto decrement section of perlop it says:

Note that just as in C, Perl doesn't define when the variable is incremented or decremented. You just know it will be done sometime before or after the value is returned. This also means that modifying a variable twice in the same statement will lead to undefined behaviour.

---

True laziness is hard work

Thanks!

Best, beth

Yes, thank you very much! I did actually use ELISHEVAS golf code as a basis for my own, now I'll review. As mentioned elsewhere in this thread, I don't like the C style loops, which was one of the reasons I picked it. My version was something like this:

    my %out;
    my @in = @{ $in };
    my $i = 0;
    while ( $i < $#in ) {
        push( @{ $out{ $in[ $i++ ] } }, $in[ $i++ ] ) ;
    }
    return \%out;
[download]

Which was basically ELISHIVAS, with dereferencing and no postfix while.


- Boldra