[perl #125580] [BUG] bag/set related issues

[Aleks-Daniel Jakimenko-Aleksejev via RT]

Bisected. First issue was resolved in
https://github.com/rakudo/rakudo/commit/11f27a30bdf380c53697330ec62e982dde68e0b0

On 2017-10-01 23:59:39, alex.jakime...@gmail.com wrote:
> 1. I think it is properly guarded now. (error message: Cannot coerce a
> lazy
> list onto a Bag)
> 2. That's OK. A lot of things require whitespace in 6lang (another
> example
> here:
>
https://docs.6lang.org/language/traps#Less_than_vs._Word_quoting/Associative_indexing
> ). If you insist on no whitespace you're free to use ⊎.
> 3. Here's the current error message: “Only identical operators may be
> list
> associative; since '(+)' and '(-)' differ, they are non-associative
> and you
> need to clarify with parentheses”. I'm not sure if (+) and (-) should
> work
> without parens.
>
> I think we need a test for the first issue, second issue can be
> rejected and
> 3rd has to be separated into a separate RFC ticket.
>
> Therefore TESTNEEDED. Whoever writes a test can decide whether 3rd
> issue should
> be rejected or separated into another ticket :)
>
> On 2015-07-09 02:27:18, liu...@360.cn wrote:
> > 15:20 < kanl> my $a = bag( -Inf .. Inf ); my $b = bag( 1 .. 3 ); my
> > $c
> > = bag();
> > say $a(+)$b(+)$c; ## this won't work
> > 15:21 < kanl> 1. Inf is not properly guarded
> > 15:21 < kanl> 2. the (whatever) operator requires leading
> > whitespaces.
> > 15:21 < kanl> 3. can't mix the operators without grouping ()
> > 15:23 < kanl> m: my $a = bag( 1 .. 4 ); my $b = bag( 1 .. 3 ); say
> > $a(+)$b;
> > 15:23 < kanl> m: my $a = bag( 1 .. 4 ); my $b = bag( 1 .. 3 ); my $c
> > =
> > bag();
> > say $a (+) $b (-) $c;
> > 15:23 <+camelia> rakudo-moar 377672: OUTPUT«===SORRY!=== Error while
> > compiling
> > /tmp/hlD7eRLLzW␤Prefix + requires an argument, but no
> > valid
> > term found␤at /tmp/hlD7eRLLzW:1␤------> .. 4 ); my
> > $b = bag(
> > 1 .. 3 ); say $a(+⏏)$b;␤ expecting any of:␤
> > prefix␤»
> > 15:24 <+camelia> rakudo-moar 377672: OUTPUT«===SORRY!=== Error while
> > compiling
> > /tmp/YpB9DyyE64␤Operators '(+)' and '(-)' are non-
> > associative
> > and require parentheses␤at /tmp/YpB9DyyE64:1␤------>
> > ( 1 .. 3
> > ); my $c = bag(); say $a (+) $b⏏ (-) $c;␤
> > expecting any
> > of:␤ i…»
> >