On 10/20/2011 01:27 PM, Jay McCarthy wrote:
On Thu, Oct 20, 2011 at 12:52 PM, Eric Tanter<etan...@dcc.uchile.cl> wrote:
Thanks Sam,
Actually, that's not what we're after.
In untyped Racket, we have a struct monad:
(struct monad
(;; A -> M A
return
;; A -> (A -> M B) -> M B
bind))
Then we have several instantiations (exception, state, what-have-you):
(define my-fancy-monad (monad (lambda ...) (lambda ...)))
How do you protect against combing the Maybe monad's bind with the
State monad's bind? Monads are more like objects where the methods
have to take the same kind of thing, not just some higher level monad
class.
I expect that's what the M type constructor is for.
It looks like Eric's monad struct is just a reification of the Haskell
type class dictionary for a monad instance (type).
Eric, is your question whether Typed Racket can parameterize a typed
structure of a type constructor rather than a type?
Ryan
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