[Grace-core] Fwd: INCOMPLETE: gradual typing + structural typing + typecase

[James Noble]

On 2/07/2013, at 17:17 PM, Kim Bruce <kim at cs.pomona.edu> wrote:

> We couldn't understand your example.  Can you explain it?

I tried recoding in Grace - this always returns 1 for me. 



type A = {
  a(_ : A) -> Done
}

type B = {
 b(_ : B) -> Done
}

def x = object { 
  var f is readable, writable, public := object {
     method a(x) {x}
     method b(y) {y}
     }
  method get {f}
  method set(g) { f := g }
}

// then x has type { get : {} -> A, set : A -> {} }

match (x.f) 
  case { b : B -> print "1" }
  case { _ -> print "2" }