xx-repeated expression enclosed in parens can't access the topic $_ of a statement modifier

[p6rt]

Migrated from rt.perl.org#126569 (status was 'resolved')

Searchable as RT126569$

[p6rt]

From @smls

This works​:

  ➜ .pick xx 10 given 1..6
  (6 3 1 1 5 1 6 3 4 2)

But putting parens around the xx operation, breaks it​:

  ➜ (.pick xx 10) given 1..6
  ((Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any))

The problem only seem to occur when $_ was set by a statement modifier - not when it was assigned to manually or set by the block form of 'given'.

An example of a useful idiom which relies on putting parens around an xx operation, is
  (EXPRESSION xx *).first(CONSTRAINT)
for "keep retrying EXPRESSION until the result matches CONSTRAINT".

[p6rt]

From @smls

Likely related to RT #​128054.

[p6rt]

From @smls

Still present in

  This is Rakudo version 2017.05-134-g0c5fe56cc built on MoarVM version 2017.05-25-g62bc54e9
  implementing Perl 6.c.

[p6rt]

From @zoffixznet

On Thu, 05 Nov 2015 01​:58​:17 -0800, smls75@​gmail.com wrote​:

This works​:

➜ .pick xx 10 given 1..6
(6 3 1 1 5 1 6 3 4 2)

But putting parens around the xx operation, breaks it​:

➜ (.pick xx 10) given 1..6
((Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any) (Any))

The problem only seem to occur when $_ was set by a statement modifier
- not when it was assigned to manually or set by the block form of
'given'.

An example of a useful idiom which relies on putting parens around an
xx operation, is
(EXPRESSION xx *).first(CONSTRAINT)
for "keep retrying EXPRESSION until the result matches CONSTRAINT".

Thank you for the report. This is now fixed.

Fix​: rakudo/rakudo@1ee89b54074e80c
Test​: Raku/roast@2f2998733a2d8132c

[p6rt]

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

[p6rt]

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