Some core Routines do not do Callable role

[p6rt]

Migrated from rt.perl.org#128905 (status was 'open')

Searchable as RT128905$

[p6rt]

From @zoffixznet

To me this looks like a bug, or at least an inconsistency. The failure to do a Callable means it can't be accepted into (&thing) in routines, which is how I discovered this​:

m​: say Any.^can("push")[0] ~~ Callable;
rakudo-moar c587b9​: OUTPUT«False␤»

m​: say Any.^can("push")[0].^mro
rakudo-moar c587b9​: OUTPUT«((Method+{<anon|42801984>}) (Method) (Routine) (Block) (Code) (Any) (Mu))␤»

m​: say Any.^can("say")[0].^mro
rakudo-moar c587b9​: OUTPUT«((Method) (Routine) (Block) (Code) (Any) (Mu))␤»

m​: sub (&thing) {}( Any.^can("push")[0] )
rakudo-moar c587b9​: OUTPUT«Type check failed in binding to &thing; expected Callable but got Method+{<anon|42801984>} (Method+{<anon|4280198...)␤ in sub at <tmp> line 1␤ in block <unit> at <tmp> line 1␤␤»

m​: sub (&thing) {}( Any.^can("say")[0] )
rakudo-moar c587b9​: ( no output )

[p6rt]

From @lizmat

The only difference between “push” and “say” I can find, is that “push” is marked “is nodal”

However, trying to replicate this outside of the setting, does work as expected​:

$ 6 'class A { proto method a() is nodal { } }; say A.^can("a")[0] ~~ Callable
True

Looks like it is even deeper, at the nqp level​:

$ 6 'use nqp; say nqp​::istype(Any.^can("push")[0],Callable)’
0

Not sure where to go from here yet

On 12 Aug 2016, at 05​:32, Zoffix Znet (via RT) <perl6-bugs-followup@​perl.org> wrote​:

# New Ticket Created by Zoffix Znet
# Please include the string​: [perl #​128905]
# in the subject line of all future correspondence about this issue.
# <URL​: https://rt-archive.perl.org/perl6/Ticket/Display.html?id=128905 >

To me this looks like a bug, or at least an inconsistency. The failure to do a Callable means it can't be accepted into (&thing) in routines, which is how I discovered this​:

m​: say Any.^can("push")[0] ~~ Callable;
rakudo-moar c587b9​: OUTPUT«False␤»

m​: say Any.^can("push")[0].^mro
rakudo-moar c587b9​: OUTPUT«((Method+{<anon|42801984>}) (Method) (Routine) (Block) (Code) (Any) (Mu))␤»

m​: say Any.^can("say")[0].^mro
rakudo-moar c587b9​: OUTPUT«((Method) (Routine) (Block) (Code) (Any) (Mu))␤»

m​: sub (&thing) {}( Any.^can("push")[0] )
rakudo-moar c587b9​: OUTPUT«Type check failed in binding to &thing; expected Callable but got Method+{<anon|42801984>} (Method+{<anon|4280198...)␤ in sub at <tmp> line 1␤ in block <unit> at <tmp> line 1␤␤»

m​: sub (&thing) {}( Any.^can("say")[0] )
rakudo-moar c587b9​: ( no output )

[p6rt]

The RT System itself - Status changed from 'new' to 'open'

[p6rt]

From @zoffixznet

Looks like this bug affects subroutines too​:

m​: say &defined ~~ Callable
rakudo-moar 3e1382​: OUTPUT​: «False␤»

m​: say [0,1,2,Any].grep(&defined)
rakudo-moar 3e1382​: OUTPUT​: «Cannot resolve caller ACCEPTS(Sub+{<anon|56691824>}​: Int); <redacted>

[p6rt]

From @zoffixznet

Also affects some methods​:

<Zoffix__> m​: my %h; say %h.AT-KEY​: 1|2
<camelia> rakudo-moar eaf609edb​: OUTPUT​: «Type check failed in binding to parameter '&call'; expected Callable but got Method+{is-nodal} (Method+{is-nodal}.new)␤ in block <unit> at <tmp> line 1␤␤»

[p6rt]

From @zoffixznet

On Wed, 13 Dec 2017 19​:23​:38 -0800, cpan@​zoffix.com wrote​:

Also affects some methods​:

<Zoffix__> m​: my %h; say %h.AT-KEY​: 1|2
<camelia> rakudo-moar eaf609edb​: OUTPUT​: «Type check failed in binding
to parameter '&call'; expected Callable but got Method+{is-nodal}
(Method+{is-nodal}.new)␤ in block <unit> at <tmp> line 1␤␤»

This bug is blocking a potential fix for RT#​125614[^1]. If you fix this ticket, please take a look if the fix for that other one can be merged.

[1] https://rt-archive.perl.org/perl6/Ticket/Display.html?id=125614