HaloO,
I wrote:
Yes, but I was conjecturing that the additions to A&B are pushed
down to A and B such that their intension sets remain strict supersets
of A&B.
Think of the Complex example that might read
role Complex does Num & !Comparable
{
method im { return 0; }
method re { return self as Num } # a no-op for Num
}
class Complex does Complex
{
has $.re; # accessor overwrites role method
has $.im; # accessor overwrites role method
}
Apart from the fact that the role and the class compete for the
same name slot this looks like what you need to make Num applicable
wherever a Complex is expected:
module A
{
use Complex;
Num $a;
say $a.im; # statically type correct, prints 0
}
module B
{
Num $b;
say $b.im; # syntactically admissible, but produces runtime error
}
Actually the 'self as Num' should return the self type ::?CLASS to
preserve as much type information as possible. Hmm, could we get
the keyword Self for that?
Have a nice weekend, TSa.
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