From matt.oates@congenica.com

The following has an empty result when using race or hyper in perl6 version 2015.10-233-gac750a9 built on MoarVM version 2015.10-61-g624d504

$ perl6

(1..10).grep(* > 3)
(4 5 6 7 8 9 10)
(1..10).race().grep(* > 3)
()
(1..10).hyper().grep(* > 3)
()

Looks specifically like the methods after the hyper/race never get called​:

(1..10).hyper().grep(* > 3).map({$_.say; $_})
()
(1..10).map({$_.say; $_}).hyper().grep(* > 3)
1
2
3
4
5
6
7
8
9
10
()

From @Mouq

On Mon Nov 09 06​:36​:49 2015, matt.oates@​congenica.com wrote​:

The following has an empty result when using race or hyper in perl6
version 2015.10-233-gac750a9 built on MoarVM version 2015.10-61-
g624d504

$ perl6

(1..10).grep(* > 3)
(4 5 6 7 8 9 10)
(1..10).race().grep(* > 3)
()
(1..10).hyper().grep(* > 3)
()

Looks specifically like the methods after the hyper/race never get
called​:

(1..10).hyper().grep(* > 3).map({$_.say; $_})
()
(1..10).map({$_.say; $_}).hyper().grep(* > 3)
1
2
3
4
5
6
7
8
9
10
()

Another, probably related case is that maps on hyper work with with normal subroutines, but not multis​:

18​:47 < Quom_> Did anyone else notice this issue​:
18​:47 < Quom_> m​: sub f($a) {$a**2}; say [+] (^100).hyper.map(&f)
18​:47 <+camelia> rakudo-moar 51d695​: OUTPUT«328350␤»
18​:47 < Quom_> m​: multi f($a) {$a**2}; say [+] (^100).hyper.map(&f)
18​:47 <+camelia> rakudo-moar 51d695​: OUTPUT«0␤»
18​:47 < Quom_> m​: multi f($a) {$a**2}; say [+] (^100).map(&f)
18​:47 <+camelia> rakudo-moar 51d695​: OUTPUT«328350␤»
18​:48 < TimToady> I think we noticed something like it the other day, dunno if anybody rakudobugged it

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

From @AlexDaniel

Regular grep​:

<AlexDaniel> m​: say ^10 .grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT«(2 3 5 7)␤»

With hyper​:

<AlexDaniel> m​: say ^10 .hyper.grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤()␤»

With race​:

<AlexDaniel> m​: say ^10 .race.grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤()␤»

More​:

<AlexDaniel> m​: my @​a = ^1000 .hyper.grep(* > 5); say @​a
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤ it has 0
  elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
  elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
  elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
  elem…»

What is this “it has 0 elements.” thing? Why do I see it? Why it returns an
empty list?

From @coke

On Wed Jan 06 06​:35​:15 2016, alex.jakimenko@​gmail.com wrote​:

Regular grep​:

<AlexDaniel> m​: say ^10 .grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT«(2 3 5 7)␤»

With hyper​:

<AlexDaniel> m​: say ^10 .hyper.grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤()␤»

With race​:

<AlexDaniel> m​: say ^10 .race.grep​: *.is-prime
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤()␤»

More​:

<AlexDaniel> m​: my @​a = ^1000 .hyper.grep(* > 5); say @​a
<camelia> rakudo-moar fec061​: OUTPUT« it has 0 elements.␤ it has 0
elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
elements.␤ it has 0 elements.␤ it has 0
elements.␤ it has 0
elem…»

What is this “it has 0 elements.” thing? Why do I see it? Why it returns an
empty list?

This was added by timo after Christmas; This debug output is the only thing in the conditional block it appears in.

$ git show 20c796cd
commit 20c796cd31e5148e2f8fd35aab4c7eca073696ca
Author​: Timo Paulssen <timonator@​perpetuum-immobile.de>
Date​: Thu Dec 31 03​:39​:49 2015 +0100

  hyper now cares about sequence numbers of work

  this code wants to get a bit cleaned up. i'm sure
  the control flow could be a bit less convoluted.

--
Will "Coke" Coleda

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

From @timo

I just kicked out the debug output, but sadly hyper + grep remains
broken. sadly, hyper + grep has been broken for a longer time :(

From alex.hartmaier@gmail.com

I've stumbled over this bug today too when using @​array.combinations(3).race.grep(&is-match).say.
Same when race is replaced by hyper.

From @smls

As another data-point, the problem only occurs when .grep is called directly on the HyperSeq returned by .hyper/.race, and not when a .map is interposed​:

  say (1..10).hyper().grep(* > 3); # ()
  say (1..10).hyper().map({$_}).grep(* > 3); # (4 5 6 7 8 9 10)

From @jnthn

On Mon, 09 Nov 2015 06​:36​:49 -0800, matt.oates@​congenica.com wrote​:

The following has an empty result when using race or hyper in perl6
version 2015.10-233-gac750a9 built on MoarVM version 2015.10-61-
g624d504

$ perl6

(1..10).grep(* > 3)
(4 5 6 7 8 9 10)
(1..10).race().grep(* > 3)
()
(1..10).hyper().grep(* > 3)
()

Looks specifically like the methods after the hyper/race never get
called​:

(1..10).hyper().grep(* > 3).map({$_.say; $_})
()
(1..10).map({$_.say; $_}).hyper().grep(* > 3)
1
2
3
4
5
6
7
8
9
10
()

Fixed in new hyper/race implementation; tests in S07-hyperrace/hyper.t and S07-hyperrace/race.t.

@jnthn - Status changed from 'open' to 'resolved'