From @masak

<amoc> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"two\"]"»
<amoc> it is a bug, right?
<masak> amoc​: [*-1]
<amoc> rakudo​: my @​a = <one two>; @​a[*-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"zero\"]"»
<masak> S09.
<jnthn> I think -1 is meant to be a syntax error these days.
<masak> jnthn​: why?
<masak> it's just out of bounds.
<jnthn> std​: @​foo[-1]
<p6eval> std 25906​: OUTPUT«##### PARSE FAILED #####␤Obsolete use of
[-1] subscript to access final element; in Perl 6 please use [*-1]
instead [...]
<amoc> from http://perlcabal.org/syn/S09.html#Negative_and_differential_subscripts
<masak> oh.
<amoc> it says​: "Using a standard index less than zero prepends the
corresponding number of elements to the start of the array and then
maps the negative index back to zero"?
<jnthn> masak​: Because STD.pm says so. But yes, you can declare an
array with different indexes too...
<jnthn> So I'm not sure what'd happen there.
<masak> shall I report this as a rakudobug?
<jnthn> You can. We're inconsistent with STD.pm there, so it's
probably worthy of a ticket.
<masak> someone put together an example for STD with a
different-indexes array, and see what it says! :)
* masak submits

From @coke

On Thu Mar 19 06​:28​:19 2009, masak wrote​:

<amoc> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"two\"]"»
<amoc> it is a bug, right?
<masak> amoc​: [*-1]
<amoc> rakudo​: my @​a = <one two>; @​a[*-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"zero\"]"»
<masak> S09.
<jnthn> I think -1 is meant to be a syntax error these days.
<masak> jnthn​: why?
<masak> it's just out of bounds.
<jnthn> std​: @​foo[-1]
<p6eval> std 25906​: OUTPUT«##### PARSE FAILED #####␤Obsolete use of
[-1] subscript to access final element; in Perl 6 please use [*-1]
instead [...]
<amoc> from
http://perlcabal.org/syn/S09.html#Negative_and_differential_subscripts
<masak> oh.
<amoc> it says​: "Using a standard index less than zero prepends the
corresponding number of elements to the start of the array and then
maps the negative index back to zero"?
<jnthn> masak​: Because STD.pm says so. But yes, you can declare an
array with different indexes too...
<jnthn> So I'm not sure what'd happen there.
<masak> shall I report this as a rakudobug?
<jnthn> You can. We're inconsistent with STD.pm there, so it's
probably worthy of a ticket.
<masak> someone put together an example for STD with a
different-indexes array, and see what it says! :)
* masak submits

This currently fails, but not in the same manner as STD​:

17​:26 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
17​:26 <+p6eval> rakudo ac8a2a​: OUTPUT«Cannot modify readonly value␤ in
  '&infix​:<=>' at line 1␤ in main program body at line
  22​:/tmp/Udd9hXZOxN␤»

--
Will "Coke" Coleda

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

From @coke

On Tue Jul 27 14​:27​:33 2010, coke wrote​:

On Thu Mar 19 06​:28​:19 2009, masak wrote​:

<amoc> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"two\"]"»
<amoc> it is a bug, right?
<masak> amoc​: [*-1]
<amoc> rakudo​: my @​a = <one two>; @​a[*-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"zero\"]"»
<masak> S09.
<jnthn> I think -1 is meant to be a syntax error these days.
<masak> jnthn​: why?
<masak> it's just out of bounds.
<jnthn> std​: @​foo[-1]
<p6eval> std 25906​: OUTPUT«##### PARSE FAILED #####␤Obsolete use of
[-1] subscript to access final element; in Perl 6 please use [*-1]
instead [...]
<amoc> from
http://perlcabal.org/syn/S09.html#Negative_and_differential_subscripts
<masak> oh.
<amoc> it says​: "Using a standard index less than zero prepends the
corresponding number of elements to the start of the array and then
maps the negative index back to zero"?
<jnthn> masak​: Because STD.pm says so. But yes, you can declare an
array with different indexes too...
<jnthn> So I'm not sure what'd happen there.
<masak> shall I report this as a rakudobug?
<jnthn> You can. We're inconsistent with STD.pm there, so it's
probably worthy of a ticket.
<masak> someone put together an example for STD with a
different-indexes array, and see what it says! :)
* masak submits

This currently fails, but not in the same manner as STD​:

17​:26 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
17​:26 <+p6eval> rakudo ac8a2a​: OUTPUT«Cannot modify readonly value␤ in
'&infix​:<=>' at line 1␤ in main program body at line
22​:/tmp/Udd9hXZOxN␤»

Another slight change​:

20​:08 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
20​:08 <+p6eval> rakudo 38165a​: OUTPUT«Cannot assign to a non-container␤ in
  block <anon> at /tmp/55lCbf7U7p​:1␤ in <anon> at
  /tmp/55lCbf7U7p​:1␤»

--
Will "Coke" Coleda

From @diakopter

On Tue Jan 10 17​:09​:46 2012, coke wrote​:

On Tue Jul 27 14​:27​:33 2010, coke wrote​:

On Thu Mar 19 06​:28​:19 2009, masak wrote​:

<amoc> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"two\"]"»
<amoc> it is a bug, right?
<masak> amoc​: [*-1]
<amoc> rakudo​: my @​a = <one two>; @​a[*-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"zero\"]"»
<masak> S09.
<jnthn> I think -1 is meant to be a syntax error these days.
<masak> jnthn​: why?
<masak> it's just out of bounds.
<jnthn> std​: @​foo[-1]
<p6eval> std 25906​: OUTPUT«##### PARSE FAILED #####␤Obsolete use
of
[-1] subscript to access final element; in Perl 6 please use [*-1]
instead [...]
<amoc> from

http://perlcabal.org/syn/S09.html#Negative_and_differential_subscripts

<masak> oh.
<amoc> it says​: "Using a standard index less than zero prepends
the
corresponding number of elements to the start of the array and
then
maps the negative index back to zero"?
<jnthn> masak​: Because STD.pm says so. But yes, you can declare an
array with different indexes too...
<jnthn> So I'm not sure what'd happen there.
<masak> shall I report this as a rakudobug?
<jnthn> You can. We're inconsistent with STD.pm there, so it's
probably worthy of a ticket.
<masak> someone put together an example for STD with a
different-indexes array, and see what it says! :)
* masak submits

This currently fails, but not in the same manner as STD​:

17​:26 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
17​:26 <+p6eval> rakudo ac8a2a​: OUTPUT«Cannot modify readonly value␤
in
'&infix​:<=>' at line 1␤ in main program body at
line
22​:/tmp/Udd9hXZOxN␤»

Another slight change​:

20​:08 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
20​:08 <+p6eval> rakudo 38165a​: OUTPUT«Cannot assign to a non-
container␤ in
block <anon> at /tmp/55lCbf7U7p​:1␤ in <anon> at
/tmp/55lCbf7U7p​:1␤»

This is now fixed. marking testneeded.

From @diakopter

On Tue May 29 15​:09​:25 2012, diakopter wrote​:

On Tue Jan 10 17​:09​:46 2012, coke wrote​:

On Tue Jul 27 14​:27​:33 2010, coke wrote​:

On Thu Mar 19 06​:28​:19 2009, masak wrote​:

<amoc> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"two\"]"»
<amoc> it is a bug, right?
<masak> amoc​: [*-1]
<amoc> rakudo​: my @​a = <one two>; @​a[*-1] = 'zero'; @​a.perl
<p6eval> rakudo f8b6ae​: RESULT«"[\"one\", \"zero\"]"»
<masak> S09.
<jnthn> I think -1 is meant to be a syntax error these days.
<masak> jnthn​: why?
<masak> it's just out of bounds.
<jnthn> std​: @​foo[-1]
<p6eval> std 25906​: OUTPUT«##### PARSE FAILED #####␤Obsolete
use
of
[-1] subscript to access final element; in Perl 6 please use
[*-1]
instead [...]
<amoc> from

http://perlcabal.org/syn/S09.html#Negative_and_differential_subscripts

<masak> oh.
<amoc> it says​: "Using a standard index less than zero prepends
the
corresponding number of elements to the start of the array and
then
maps the negative index back to zero"?
<jnthn> masak​: Because STD.pm says so. But yes, you can declare
an
array with different indexes too...
<jnthn> So I'm not sure what'd happen there.
<masak> shall I report this as a rakudobug?
<jnthn> You can. We're inconsistent with STD.pm there, so it's
probably worthy of a ticket.
<masak> someone put together an example for STD with a
different-indexes array, and see what it says! :)
* masak submits

This currently fails, but not in the same manner as STD​:

17​:26 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero';
@​a.perl
17​:26 <+p6eval> rakudo ac8a2a​: OUTPUT«Cannot modify readonly
value␤
in
'&infix​:<=>' at line 1␤ in main program body at
line
22​:/tmp/Udd9hXZOxN␤»

Another slight change​:

20​:08 < [Coke]> rakudo​: my @​a = <one two>; @​a[-1] = 'zero'; @​a.perl
20​:08 <+p6eval> rakudo 38165a​: OUTPUT«Cannot assign to a non-
container␤ in
block <anon> at /tmp/55lCbf7U7p​:1␤ in <anon> at
/tmp/55lCbf7U7p​:1␤»

This is now fixed. marking testneeded.

added test in a9a75b0; resolving.

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