From eternaleye@gmail.com

This code causes Parrot to fail in a rather spectacular manner​:

role TreeNode[​::T] does Positional {
  has TreeNode[T] @​!children handles 'postcircumfix​:<[ ]>';
  has T $.data is rw;
};
my $tree = TreeNode[Int].new;
$tree.data = 3;
$tree[0] = TreeNode[Int].new;
$tree[1] = TreeNode[Int].new;
$tree[0].data = 1;
$tree[1].data = 4;
.say for $tree.data, $tree[0,1]>>.data;

From @moritz

Current output​:

In "has" declaration, typename TreeNode must be predeclared (or marked
as declarative with :​: prefix) at line 2, near "[T] @​!chil"
current instr.​: 'perl6;HLL;Grammar;panic' pc 500 (ext

Which is also wrong, but less scary.

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

From @coke

On Sun Aug 02 13​:58​:12 2009, eternaleye@​gmail.com wrote​:

This code causes Parrot to fail in a rather spectacular manner​:

role TreeNode[​::T] does Positional {
has TreeNode[T] @​!children handles 'postcircumfix​:<[ ]>';
has T $.data is rw;
};
my $tree = TreeNode[Int].new;
$tree.data = 3;
$tree[0] = TreeNode[Int].new;
$tree[1] = TreeNode[Int].new;
$tree[0].data = 1;
$tree[1].data = 4;
.say for $tree.data, $tree[0,1]>>.data;

This now outputs​:
3
1
4

Needs tests.

--
Will "Coke" Coleda

From @moritz

Tested in t/spec/S14-roles/parameterized-type.t.

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