@@ -329,9+329,7 @@ any type `α`, as long as your function is of type `α -> α` and you have a bas
-- Or this:
let sysf_true = (\y n -> y) :: Sysf_bool a
-- Or this:
let sysf_true = (\y n -> y) :: Sysf_bool a
- Note that in both OCaml and the Haskell code, the generalization `∀'a` on the free type variable `'a` is implicit. If you really want to, you can supply it explicitly in Haskell by saying:
-
- :set -XExplicitForAll
+ :set -XExplicitForAll
let { sysf_true :: forall a. Sysf_bool a; ... }
-- or
let { sysf_true :: forall a. a -> a -> a; ... }
let { sysf_true :: forall a. Sysf_bool a; ... }
-- or
let { sysf_true :: forall a. a -> a -> a; ... }
@@ -408,7+406,7 @@ Be sure to test your proposals with simple lists. (You'll have to `sysf_cons` up
# k 1 true ;;
- : int = 1
# k 1 true ;;
- : int = 1
- If you can't understand how one term can have several types, recall our discussion in this week's notes of "principal types". (WHERE?)
+ If you can't understand how one term can have several types, recall our discussion in this week's notes of "principal types".