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Postings from July 2013
On 27 June 2013 03:59, Ricardo Signes <perl.p5p@rjbs.manxome.org> wrote:
>
> We can add postfix syntax for dereferencing to work in *all* places that we
> might dereference, creating a construct that is clearly syntactically an array
> (or hash, etc.) when needed.
>
> push $x->{foo}->[0]->m->@*, $y;
>
> push @y, $x->{foo}->[0]->m->@*;
>
> subroutine( $x->{foo}->[0]->m->@* )
>
> print $delivery->{email}->body_string_ref->$*;
Also $href->%* I suppose.
Can we talk about failure modes a bit?
A common idiom is to write @{ $foo || [] } in case $foo might be undefined.
Do you remember the conditional-dereference operator that was
bikeshedded to oblivion? ($foo?->bar() was one of the proposed
syntaxes). Can we have this, plus ->@*, plus ?->@* that would expand
to an empty list if its argument is undef?
>
> If we want the two forms to be really of equivalent value, we'll also need to
> be concerned with:
>
> print "Things: $aref_of_things->@*"
>
> ...which gets into less clearly-introduceable behavior.
$foo and @foo are interpolated in strings, but not %foo. I suppose
->%* would not either? or maybe just exclude those constructs from
interpolation whatsoever?
>
> Finally, do we need to enable postfix slices? I think that if we can, we
> should. I think the syntax is free.
>
> say for $href->{aref}->@[ 0, 2, 4 ];
>
> say for $aref->[ $h_idx ]->@{ qw(foo bar baz) };
>
> I think we have a few options for the specific tokens to put after that last
> arrow. I think $* and @* and so on work well. Replacing the splat with a
> colon has been suggested as well. The point here is to provide the feature.
> It's not about reducing total punctuation. This is Perl, and we must embrace
> our punctuation! It's about simplifying the reading of code by allowing it to
> be read and written linearly.
>
> --
> rjbs
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