Hi all,
While trying to convert Haskell statements like this to Perl 6:
data Cxt = CxtVoid -- ^ Context that isn't expecting any values
| CxtItem !Type -- ^ Context expecting a value of the specified type
| CxtSlurpy !Type -- ^ Context expecting multiple values of the
-- specified type
deriving (Eq, Show, Ord)I'd like to be able to write it something like this:
type Cxt is CxtVoid
| CxtItem of Type
| CxtSlurpy of Type
does (Eq, Show, Ord);To be a shorthand for:
type CxtVoid;
type CxtItem of Type;
type CxtSlurpy of Type;
type Perl::Cxt is CxtVoid | CxtItem | CxtSlurpy
does Eq does Show does Ord;Is this overloading the 'of' operator too far?
For many there will be a lot of new concepts there. For a start, I'm assuming that "of" is being used as a higher order type definition, much like "Array of Wotsits" would declare. Also, there is a type there - CxtVoid - which is nothing but a Type! No representation. Of course, if you have a variable of type Cxt, and it is a CxtVoid, then that will need to be represented in some way. But you generally wouldn't care how.
An alternative might be to try to shoe-horn the concepts into Roles etc. Who knows, perhaps they'll even fit! :-)
Sam.
