[perl #123060] [BUG] `$++` statements in routines sometimes give the anonymous variable `my` scoping, sometimes `state` scoping in Rakudo

[Carl Mäsak]

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<masak> is there a recent spec commit for `$` in non-signature use? I
can't seem to find it by skimming the spec log.
<masak> ISTR it being this year, so I shouldn't even have to look that far back.
<masak> ah, found this:
https://github.com/rakudo/rakudo/commit/ce263122bc0ae6e2fee51c166c06abd9d00ba771
<masak> that one only *speculates* that the semantics be `state $`, though.
<masak> I haven't found a spec or decision about it.
<masak> right now the semantics seems to be `my`...
<masak> m: sub foo { ($ = "A")++ }; say foo for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«A␤A␤A␤A␤A␤»
<lizmat> m: sub a { $++ }; say a; say a    # I think that's state by default
<camelia> rakudo-moar 315ec6: OUTPUT«0␤1␤»
<masak> waitwait
<masak> lizmat: how is yours qualitatively different from mine?
<lizmat> not by much
<masak> the only difference I see is the assignment.
<masak> and yet they have different behaviors. o.O
<lizmat> I'd say, yours is NYI
* masak submits rakudobug
<masak> something is *very* fishy there.
<lizmat> m: sub foo { ($ = 0)++ }; say foo for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«0␤0␤0␤0␤0␤»
<vendethiel> masak: it's my $; not state $
<vendethiel> (bare $ is, I mean)
<masak> vendethiel: what makes you say that?
<masak> vendethiel: see lizmat++'s first eval.
<vendethiel> seeing the commit that added it to rakudo :-)
<vendethiel> and telling TimToady: NOT TO MAKE IT STATE :P
<masak> huh.
<masak> why not?
<lizmat> m: sub a { $++ }; say a for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«0␤1␤2␤3␤4␤»
<masak> seems it is in some cases...
<vendethiel> masak: ETOOMUCHMAGIC.
<vendethiel> ETOOIMPLICIT
<lizmat> fwiw, I'm fine with state, as my wouldn't make much sense
<masak> I'm fine with state, too.
<masak> I can see where vendethiel is coming from, but I don't mind much.
<vendethiel> newcomers will mind...
<masak> if I can write `$++` instead of `(state $)++` 500 times before
I die, that will be worth it :)
<vendethiel> ++state is cool too :p
<vendethiel> or er, state++
<masak> m: sub foo { ++$ }; say foo for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«1␤2␤3␤4␤5␤»
<vendethiel> m: sub a { state++ }; say a for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«===SORRY!=== Error while
compiling /tmp/7a8JxXYEd3␤Malformed state [...]
<vendethiel> m: sub a { (state)++ }; say a for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«===SORRY!=== Error while
compiling /tmp/8nHJRjW3si␤Malformed state [...]
<vendethiel> meh.
<masak> declarators don't work that way.
<masak> they want a declaratee.
<vendethiel> and when do they want it
<masak> vendethiel: I mean, I can't think of a single case where you
write a declarator (`my`, `our`, `state`, `has`, etc) and then nothing
afterwards. it feels "wrong", parsing-wise.
<vendethiel> well, semantics-wise for me
<lizmat> m: sub a { (state $ = "A")++ }; say a for ^5
<camelia> rakudo-moar 315ec6: OUTPUT«A␤B␤C␤D␤E␤»
<lizmat> m: sub a { ($ = "A")++ }; say a for ^5   # should just be the same
<camelia> rakudo-moar 315ec6: OUTPUT«A␤A␤A␤A␤A␤»