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Postings from June 2019
On Tue, 12 Feb 2019 15:03:01 -0800, tonyc wrote:
> On Tue, 12 Feb 2019 01:40:32 -0800, hv wrote:
> > On Mon, 11 Feb 2019 21:32:43 -0800, tonyc wrote:
> > > On Fri, 20 Jan 2017 06:43:12 -0800, hv wrote:
> > > > The scopestack imbalance here occurs because we call
> > > > sublex_start()
> > > > but never a corresponding sublex_done().
> > [...]
> > > The closing ) is confusing the parser.
> > >
> > > Patch which *might* fix it (passes all tests in a DEBUGGING build)
> > > attached.
> >
> > It looks credible to me, and a good solution. What are your concerns
> > about it?
>
> Mostly I was confused by the parser doing this:
>
> $ ./perl -Ilib -MO=Deparse -e 'qq/@{s{0}}/'
> join $", @s{'0'};
> -e syntax OK
>
> while I expected the s{0} to be treated as the beginning of a s///.
>
> > I know very little about the grammar, but I'm curious why "FUNC
> > SUBLEXSTART optexpr SUBLEXEND" is in 'term' rather than next to "FUNC
> > '(' optexpr ')'" in 'listop' - I'm assuming the cases hitting the
> > former with the patch would previously have hit the latter.
>
> This is from the history of the patch. Originally I had an extra
> production called sublexexpr that I'd added to term, since first rule
> I converted to use the new tokens was the '(' expr ')' case for term.
>
> But that rule isn't used - subparses always generate something like
> the FUNC() call (where FUNC might be op_stringify for "..."), and I
> ended up adding the FUNC rule to sublexexpr too.
>
> Testing found that the {expr} sublex token rule wasn't being used so I
> removed it, and finally added the remaining rule to term. Which is
> probably the wrong place.
>
> > Is it possible to construct an additional croak/toke test for the \U
> > case, or does the means of construction imply it cannot trigger
> > failure the same way?
>
> I think it can, though I couldn't reproduce it with an unpatched
> blead.
>
> I've attached an updated patch that moves the rule, and some attempts
> at making qq() reproduce the problem, though I couldn't make them
> crash.
>
> Tony
Applied as 69afcc21edd23e38a4aff806a14e666d77f2bd0c.
Tony
---
via perlbug: queue: perl5 status: open
https://rt.perl.org/Ticket/Display.html?id=130585