From @masak

<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a »,« @​b) »,« @​a ->
$a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT«Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a >>,<< @​b) >>,<< @​a
-> $a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT«Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> <TimToady> that looks like a bug
* masak submits rakudobug
* moritz_ doesn't understand why
<moritz_> @​a »,« @​b return a list that's twice as long as @​a
<moritz_> so the error message is fine
<masak> there's no trickery with Parcels going on, then?
<moritz_> without the parens, one could argue about list associativity
<masak> if there's list associativity, the parens shouldn't matter...
<TimToady> there's no list context for @​a »,« @​b, so it should produce
a structure of parcels of the same length
<TimToady> hyperops aren't listy like zips

From @masak

On Thu Sep 09 00​:07​:14 2010, masak wrote​:

<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a �,� @​b) �,� @​a
->
$a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT�Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a >>,<< @​b) >>,<< @​a
-> $a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT�Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> <TimToady> that looks like a bug
* masak submits rakudobug
* moritz_ doesn't understand why
<moritz_> @​a �,� @​b return a list that's twice as long as @​a
<moritz_> so the error message is fine
<masak> there's no trickery with Parcels going on, then?
<moritz_> without the parens, one could argue about list associativity
<masak> if there's list associativity, the parens shouldn't matter...
<TimToady> there's no list context for @​a �,� @​b, so it should
produce
a structure of parcels of the same length
<TimToady> hyperops aren't listy like zips

<phenny> masak​: 19​:36Z <[Coke]> tell masak I can't read
https://rt-archive.perl.org/perl6/Ticket/Display.html?id=77746
* masak looks
<masak> that is an odd bug. how did it end up like that? :/
<masak> anyway, I think I can read it.
<masak> [Coke]​: �,� should be »,«
<[Coke]> masak​: can you mark that on the ticket? Thanks.
<masak> [Coke]​: will do.

@masak - Status changed from 'new' to 'open'

From @coke

On Thu Oct 20 12​:48​:05 2011, masak wrote​:

On Thu Sep 09 00​:07​:14 2010, masak wrote​:

<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a �,� @​b) �,� @​a
->
$a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT�Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a >>,<< @​b) >>,<< @​a
-> $a, $b, $c {say "$a $b $c"}
<p6eval> rakudo 859f2d​: OUTPUT�Sorry, sides are of uneven length and
not dwimmy. [...]
<masak> <TimToady> that looks like a bug
* masak submits rakudobug
* moritz_ doesn't understand why
<moritz_> @​a �,� @​b return a list that's twice as long as @​a
<moritz_> so the error message is fine
<masak> there's no trickery with Parcels going on, then?
<moritz_> without the parens, one could argue about list associativity
<masak> if there's list associativity, the parens shouldn't matter...
<TimToady> there's no list context for @​a �,� @​b, so it should
produce
a structure of parcels of the same length
<TimToady> hyperops aren't listy like zips

<phenny> masak​: 19​:36Z <[Coke]> tell masak I can't read
https://rt-archive.perl.org/perl6/Ticket/Display.html?id=77746
* masak looks
<masak> that is an odd bug. how did it end up like that? :/
<masak> anyway, I think I can read it.
<masak> [Coke]​: �,� should be »,«
<[Coke]> masak​: can you mark that on the ticket? Thanks.
<masak> [Coke]​: will do.

Behavior changed​:

00​:47 <[Coke]> r​: rakudo​: my @​a=<a a a>;my @​b=<b b b>;for (@​a »,« @​b) »,« @​a ->
  $a, $b, $c {say "$a $b $c"}
00​:47 <camelia> rakudo 45ae2d​: OUTPUT«===SORRY!===â�¤Two terms in a rowâ�¤at
  /tmp/SrZN6trE4C​:1â�¤------> rakudoâ��​: my @​a=<a a a>;my @​b=<b b
  b>;for (@​a »,â�¤ expecting any of​:â�¤ argument listâ�¤
  postfixâ�¤ infix stopperâ�¤ infix or meta-infixâ�¤
  sâ�¦

--
Will "Coke" Coleda

From @masak

coke (>)​:

Behavior changed​:

[...]

Behavior did change, but that eval contained a thinko. The new behavior
is this​:

<masak> r​: my @​a=<a a a>;my @​b=<b b b>;for (@​a »,« @​b) »,« @​a -> $a, $b,
$c {say "$a $b $c"}
<camelia> rakudo 0e206e​: OUTPUT«Lists on both side of non-dwimmy hyperop
of infix​:<,> are not of the same lengthâ�¤left​: 6 elements, right​: 3
elements� in sub hyper [...]

Which, according to TimToady's original assessment -- previously in this
RT thread -- is wrong​:

<TimToady> there's no list context for @​a »,« @​b, so it should produce
a structure of parcels of the same length
<TimToady> hyperops aren't listy like zips

From @coke

On Sun May 26 00​:30​:48 2013, masak wrote​:

coke (>)​:

Behavior changed​:

[...]

Behavior did change, but that eval contained a thinko. The new behavior
is this​:

<masak> r​: my @​a=<a a a>;my @​b=<b b b>;for (@​a »,« @​b) »,« @​a -> $a, $b,
$c {say "$a $b $c"}
<camelia> rakudo 0e206e​: OUTPUT«Lists on both side of non-dwimmy hyperop
of infix​:<,> are not of the same lengthâ�¤left​: 6 elements, right​: 3
elements� in sub hyper [...]

Which, according to TimToady's original assessment -- previously in this
RT thread -- is wrong​:

<TimToady> there's no list context for @​a »,« @​b, so it should produce
a structure of parcels of the same length
<TimToady> hyperops aren't listy like zips

Behavior is changed again in the GLR branch​:

08​:58 < GLRelia> ..rakudo-moar 2ccea7​: OUTPUT«Lists on either side of non-dwimmy hyperop of infix​:<,> are not of the same
  lengthâ�¤left​: 2 elements, right​: 1 elementsâ�¤ in block <unit> at /tmp/tmpfile​:1â�¤â�¤Â»
--
Will "Coke" Coleda

From @niner

The current behavior is actually correct. HYPER is recursive. So it ends up calling HYPER(infix​:<,>, ("a", "b"), "a") which then fails.
Added a hint to that effect in Rakudo commit 99ee82c5af7179641b5f13543baac23b0baaf66c

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