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Postings from August 2013
* Father Chrysostomos <sprout@cpan.org> [2013-08-14T12:03:29]
> Ricardo Signes wrote:
> > « $x->@* acts exactly like @$x » is the rule. "Except in interpolation" would
> > be the exception.
>
> So we allow "$x->@*" and "$$x->@*" and "$x->$*->@*".
>
> What about the brace forms? How far does the equivalance of "@{...}"
> and "...->@*" hold?
>
> "@{$foo}" --> "$foo->@*" # 1
> "@{$foo[0]}" --> "$foo[0]->@*" # 2
> "@{*$foo}" ??? # 3
> "@{$foo->**}" --> "$foo->**->@*" # 4
> "@{$foo->()}" --> "$foo->()->@*" # 5
> "@{$foo++}" --> "$foo++->@*" # 6
> "@{$foo ? bar() : []}" => "$foo ? bar() : []->@*" # 7
We allow ->@* at the end of an expression that we would've allowed up to that
point. Of your examples above, which I've taken the liberty of numbering, #1
and #2 qualify. Of the rest, none do.
So far, I don't feel like I've seen a real argument that this is complicating
the language. From my thready knowledge of the guts here, I also think the
changes to the internals are pretty minor, but I'm happy to be proved wrong.
That said, I have softened just a little because I got to thinking that what
we'd really benefit from is a generic "interpolate this expression" syntax,
which is in Ruby as "foo #{ expr } bar" or the same in Perl 6 without the
octothorpe.
In Perl 5, of course, we have this in a sense: "foo @{[ expr ]} bar" and "foo
${\ expr } bar". Possibly that's as good as it gets, since such a syntax would
need to either force one context or have two forms. And either way, it's
circumfix.
So: "@{ $foo->[0] }" isn't so bad; generic interpolation form
We lose more simplicity with:
"@{ $foo }[0,2]"
vs.
"$foo->@[0,2]"
...because the idea that "@{...}" is "generic interpolation" no longer holds
together.
--
rjbs
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