Type system questions.

With the recent discussion on type sigils, and the fact that Pugs
is moving toward the OO core, I'd like to inquire how the following
statements evaluate (or not):

    # Compile time type arithmetic?
    ::Dual ::= ::Str | ::Num;
    $*Dual ::= ::Str | ::Num;

    # Run time type arithmetic?
    my ::dual := ::Str | ::Num;

    # Type Instantiation?
    sub apply (&fun<::a> returns ::b, ::a $arg) returns ::b {
	&fun($arg);
    }

    # Does Role live in the same namespace as Types/Classes/Modules/Packages?
    my ::role = role { ... };

    # Can class take type parameters like Roles cna?
    class Pet[Type $petfood] {
	method feed (::($petfood) $food) {...}
    }

    # Single colon as tuple composer?
    my $Triple		::= :(Bool, Int, Str);
    my $TripleTuple	::= :($Triple, $Triple);
    my &pair_with_int	::= -> Type ::t { :(::t, Int) };

Thanks,
/Autrijus/

• Type system questions. by Autrijus Tang
• Re: Type system questions. by Larry Wall
• Re: Type system questions. by Autrijus Tang
• Re: Type system questions. by Larry Wall
• Re: Type system questions. by Thomas Sandlaß