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Postings from February 2003
On Fri, Feb 21, 2003 at 08:25:56AM +0200, Jarkko Hietaniemi wrote:
> > > > Bleadperl or 5.8.0:
> > > >
> > > > $ ./perl -e 'local ${"FOO"}=1'
> > > > Can't localize through a reference at -e line 1.
> > > > $
> > > >
> > > > What reference where?
>
> > > Ronald J Kimball <rjk@linguist.Thayer.dartmouth.edu>:
> > > That's a symbolic reference, isn't it?
>
> Syntactically yes, but semantically it isn't, all that needs to be
> known about the variable name is known in compiletime. In other
> words, I would have expected the above to be equivalent to ${FOO}
> or $FOO.
>
> > Mark-Jason Dominus:
> > Perhaps the best way to address this would be to extend the peephole
> > optimizer to optimize ${"COMPILE_TIME_CONSTANT"} to
> > $COMPILE_TIME_CONSTANT.
>
> Yup, something like that.
This cannot go without making lexical variables accessible through
symbolic references.
I don't think it would be acceptable that '$a="b"; $$a' and '${"b"}'
work differently ( since ${"b"} would be optimized to $b, it will
access the lexical in the first place, unlike $$a ).
IMO, it's preferable to keep the old behavior.
Regards
Adi
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