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Postings from February 2018
On Wed, Feb 21, 2018 at 06:56:26PM +0000, Zefram wrote:
> Dave Mitchell wrote:
> >The more I think about this, the more I think that attributes should
> >be allowed in *either* position, with a warning or croak for specific
> >attributes found in the "wrong" location:
>
> That would be a bad idea.
[snip]
Ok, I'm convinced (mostly).
I plan to do the following two things shortly (assuming they prove
feasible):
1) change the parser so that subs under 'use feature signatures' use
a different grammar rule than subs not under it - possibly by making the
toker return two different sub tokens, e.g. 'SUB' and a new 'SIGSUB'
token say, depending on whether the feature is in scope.
This will then help reduce confusing errors, e.g. this code with a syntax
error (attrs before prototype):
no feature 'signatures';
sub f :lvalue ($$@) { $x = 1 }
currently gives:
Illegal character following sigil in a subroutine signature at
..., near "($"
It's parsing the ($$@) as a sub signature even though signatures aren't in
scope, so the error message is confusing.
2) For the signature sub grammar rule, allow it to spot attributes
following a signature and croak with a meaningful error. Which is what the
OP requested.
--
But Pity stayed his hand. "It's a pity I've run out of bullets",
he thought. -- "Bored of the Rings"
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