Thanks! I guess I'm kind of lucky for this bug, otherwise I might have
taken a lot longer to figure out what to do. :)
On Wed, May 7, 2014 at 4:44 AM, Larry Wall <la...@wall.org> wrote:
> On Sun, May 04, 2014 at 10:40:16AM +0100, Philip Hazelden wrote:
> : Hi,
> :
> : I'm trying to create a one-element array containing a hash. I eventually
> : managed to do this from the REPL, but when I create a script containing
> the
> : same commands, it doesn't work.
> :
> : $ cat test.p6
> : my %h = (y => 1, x => 1);
> : say [item %h].elems;
> : say [item %h][0].WHAT;
> : $ perl6 test.p6
> : 2
> : (Pair)
> : $ cat test.p6 | perl6
> : > my %h = (y => 1, x => 1);
> : ("x" => 1, "y" => 1).hash
> : > say [item %h].elems;
> : 1
> : > say [item %h][0].WHAT;
> : (Hash)
> : >
> : $ perl6 -v
> : This is perl6 version 2014.04 built on parrot 6.1.0 revision 0
> :
> : `cat test.p6 | perl6` does what I expect it to, but `perl6 test.p6` seems
> : to be flattening the hash into the array despite the 'item'.
>
> item as a list operator is going to put %h into a list context and
> flatten it into two pairs before the function ever sees it, so the
> 2/(Pair) is actually correct behavior. What's really going on in
> the other case is that the REPL is somehow losing the contents of
> %h between the prompts. You can show this is what is happening by
> putting all three lines on a single line, in which case the REPL
> version behaves like the run-from-file version.
>
> : Is this a bug, or am I missing something? (I don't claim much
> understanding
> : of how this *should* work, but getting two different behaviours feels
> : wrong.)
>
> Yes, but the bug is facing the other direction. :-)
>
> : On a whim, I tried to replace 'item %h' with '%h.item', and both methods
> of
> : execution now give the results I was expecting, i.e. "1" and "(Hash)".
>
> That avoids the list flattening before itemizing. You can also just
> write $(%h) or even $%h there to have the same effect.
>
> Larry
>
