On Fri, 20 May 2016 15:32:02 -0700, sml...@gmail.com wrote:
> The .gist call in the following code hangs indefinitely:
>
> my @a = 1..Inf; foo @a; sub foo(*@_) { say @_.gist };
>
> It shouldn't hang, because checking the argument for laziness returns
> True, and indexing it does not hang either:
>
> my @a = 1..Inf; foo @a; sub foo(*@_) { say @_.is-lazy }; # True
> my @a = 1..Inf; foo @a; sub foo(*@_) { say @_[42] }; # 43
>
> And now, this is where it gets really weird: When calling `.is-lazy`
> or `.[]` on the parameter *first*, then a *subsequent* .gist on it no
> longer hangs:
>
> my @a = 1..Inf; foo @a; sub foo(*@_) { say @_.is-lazy; say @_.gist
> }; # True[...]
> my @a = 1..Inf; foo @a; sub foo(*@_) { say @_[1]; say @_.gist
> }; # 1[...]
>
> For comparison, here are some variations which also do not hang:
>
> my @a = 1..Inf; say @a.gist; # [...]
>
> my @a = 1..Inf; foo @a; sub foo(@_) { say @_.gist }; # [...]
>
> my @a = 1..Inf; foo @a; sub foo(*@_ is raw) { say @_.gist }; # (1 2
> 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
> 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
> 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74
> 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
> 98 99 100 ...)
>
>
> ---
> This is Rakudo version 2016.04-210-gc59e4dc built on MoarVM version
> 2016.05
> implementing Perl 6.c.
Thank you for the report. This is now fixed.
Fix: https://github.com/rakudo/rakudo/commit/5e6b38789a
Test: https://github.com/perl6/roast/commit/5653ebb91b
