Re^6: Syntax for casting map to a hash or an array

Wait, what part works, but for not the same reason?

These two work for exactly the same reason.

say Dumper({map { $_ => 'fish' } qw(one two red blue)});
say Dumper([map { $_ => 'fish' } qw(one two red blue)]);
[download]

These two work but NOT for the same reason, because there's an extra layer of ref->hash->ref going on?
That's the difference you're talking about, right?

say Dumper(\@{ {map { $_ => 'fish' } qw(one two red blue)} } );
say Dumper({map { $_ => 'fish' } qw(one two red blue)});
[download]

Thanks,
cbeckley

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Re^7: Syntax for casting map to a hash or an array by shmem (Chancellor) on Apr 05, 2017 at 19:07 UTC
The first two work. In the upper, an anoymous hash is constructed with map's output, in the lower, an anonymous array. In each case, `Dumper` just get's passed the reference and dereferences it. These two work but NOT for the same reason, because there's an extra layer of ref->hash->ref going on? `say Dumper(\@{ {map { $_ => 'fish' } qw(one two red blue)} } );` [download] This one doesn't work, because the code is trying to dereference the anonymous hash as an array (`@{ }`). The next one is just like the upper one from the former code block. perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply] [d/l] [select]
Re^8: Syntax for casting map to a hash or an array by cbeckley (Curate) on Apr 05, 2017 at 19:14 UTC
Ugh, right, that was a typo. I was trying to compare these two lines. `say Dumper(\%{ {map { $_ => 'fish' } qw(one two red blue)} } ); say Dumper({map { $_ => 'fish' } qw(one two red blue)});` [download] Thank you for the correction. Thanks, cbeckley	[reply] [d/l]
Re^9: Syntax for casting map to a hash or an array by shmem (Chancellor) on Apr 05, 2017 at 19:28 UTC
Yes, these two are exactly the same, except for one gratitous reference-dereference round trip. If you dereference a reference and take a reference to the dereferenced reference, this reference will be the same as the original reference. `#!/usr/bin/perl -l $h = {map { $_ => 'fish' } qw(one two red blue)}; print $h; print \%{$h}; print \%{\%{$h}}; print \%{\%{\%{$h}}}; print \%{\%{\%{\%{$h}}}}; print \%{\%{\%{\%{\%{$h}}}}}; print \%{\%{\%{\%{\%{\%{$h}}}}}}; print \%{\%{\%{\%{\%{\%{\%{$h}}}}}}}; print \%{\%{\%{\%{\%{\%{\%{\%{$h}}}}}}}}; __END__ HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548) HASH(0x17ea548)` [download] Sorry for so may ref-deref, couldn't stop... %-) perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'	[reply] [d/l]
Re^10: Syntax for casting map to a hash or an array by stevieb (Canon) on Apr 05, 2017 at 19:30 UTC