Ah, got it, thanks.
It's mildly vexing, but the kind of side-effecty coding I described isn't a
great idea in general. I only stumbled across the phenomenon while code
golfing.
As a side note, code like this:
sub f { 1 ... * ~~ /9/; $/ }
...produces an untrue warning "Useless use of ... in sink context". Not
sure if it's worth filing a bug report...
On Wed, Dec 28, 2022 at 12:49 PM Elizabeth Mattijsen <l...@dijkmat.nl> wrote:
> That's because it at one time was decided that smart-match would set $/ in
> the caller's scope. Which is a pain for implementation and optimizations.
> I would be very much in favour of getting rid of that "feature", fwiw.
>
> > On 28 Dec 2022, at 18:45, Sean McAfee <eef...@gmail.com> wrote:
> >
> > But if a sequence has its own $/, why does * ~~ /9/ set $/?
> >
> > Actually it's not just sequences, as a little more experimentation
> showed:
> >
> > [0] > first /9/, ^Inf
> > 9
> > [1] > $/
> > Nil
> > [2] > grep /9/, ^10
> > (9)
> > [3] > $/
> > Nil
> >
> > The * ~~ "trick" sets $/ in these cases too.
> >
> >
> > On Wed, Dec 28, 2022 at 12:01 PM Elizabeth Mattijsen <l...@dijkmat.nl>
> wrote:
> > This isn't specific to the REPL:
> >
> > $ raku -e 'say 1 ... /9/; say $/'
> > (1 2 3 4 5 6 7 8 9)
> > Nil
> >
> > I can only assume that the sequence has its own scope for $/, and thus
> isn't visible outside of it.
> >
> >
> > Liz
> >
> > > On 28 Dec 2022, at 16:47, Sean McAfee <eef...@gmail.com> wrote:
> > >
> > > In a fresh 2022.12 Raku REPL, when the endpoint of a sequence is a
> Regex, the $/ variable seems not to be set:
> > >
> > > [0] > 1 ... /9/
> > > (1 2 3 4 5 6 7 8 9)
> > > [1] > $/
> > > Nil
> > >
> > > If I match more explicitly using a WhateverCode, it works:
> > >
> > > [2] > 1 ... * ~~ /9/
> > > (1 2 3 4 5 6 7 8 9)
> > > [3] > $/
> > > ｢9｣
> > >
> > > Is this the intended behavior, or a bug?
> > >
> >
>
>
