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Re: my $@ - a proposal

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Hi Yuval, hi p5p,
Yuval Kogman wrote:
> It would be interesting to find a way for 'use 5.012' code to
> automatically create a lexical $@, similarly to how $1, $2 etc are
> treated
If one created a pragma to enable this behaviour lexically, one could
use the same logic for loading it by default with use 5.012 as I
proposed with my use-strict-by-default patch. Unfortunately, the
implications with respect to what happens in -E weren't clear since
those essentially do a "use 5.0CURRENT" but probably shouldn't add any
new behaviour. Eventhough that change in behaviour was mostly liked, the
patch hasn't made it in for this very reason. Rafael said he's still
thinking about it.
For checking whether to create a lexical or not, you could then use a
hint. So the plan would be:
- Make it possible to declare $@ as a lexical at all: "Can't use global
$@ in "my" at -e line 1, near "my $@""
- patch the core eval BLOCK implementation to create a lexical if the
hint is set
- create a simple pragma to set/unset the hint
- apply aforementioned strict-by-default patch with
s/strict/lexicalExceptions/g
One potential gotcha might be that if using a hints *hash* entry, the
hash lookup on each eval {} could be considered large. I'm not sure, though.
Cheers,
Steffen

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• my $@ - a proposal by Yuval Kogman
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Mark Mielke
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Graham Barr
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Ben Morrow
• Re: my $@ - a proposal by Graham Barr
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Johan Vromans
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Rafael Garcia-Suarez
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Ben Morrow
• Re: my $@ - a proposal by Elliot Shank
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Juerd Waalboer
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Sean O'Rourke
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Steffen Mueller
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by David Cantrell
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Nicholas Clark
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Reini Urban
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Sam Vilain