Parentheses generation benchmark: GHCi vs. OCaml vs. Poly/ML

ghci

lolcathost% ghci
GHCi, version 7.10.1: http://www.haskell.org/ghc/  :? for help
> type F a = (a, a)
> type G a = F (F a)
> type H a = G (G a)
> type I a = H (H a)
> type J a = I (I a)
> type K a = J (J a)
> let f :: a -> F a ; f x = (x, x)
> let g :: a -> G a ; g x = f (f x)
> let h :: a -> H a ; h x = g (g x)
> let i :: a -> I a ; i x = h (h x)
> let j :: a -> J a ; j x = i (i x)
> let k :: a -> K a ; k x = j (j x)
  C-c C-c^CInterrupted.

ocaml

lolcathost% eval `opam config env`
lolcathost% ocaml
        OCaml version 4.02.3

# type 'a f = 'a * 'a
  type 'a g = 'a f f
  type 'a h = 'a g g
  type 'a i = 'a h h
  type 'a j = 'a i i
  type 'a k = 'a j j
  let f x : 'a f = x, x
  let g x : 'a g = f (f x)
  let h x : 'a h = g (g x)
  let i x : 'a i = h (h x)
  let j x : 'a j = i (i x)
  let k x : 'a k = j (j x);;
type 'a f = 'a * 'a
type 'a g = 'a f f
type 'a h = 'a g g
type 'a i = 'a h h
type 'a j = 'a i i
type 'a k = 'a j j
val f : 'a -> 'a f = <fun>
val g : 'a -> 'a g = <fun>
val h : 'a -> 'a h = <fun>
val i : 'a -> 'a i = <fun>
val j : 'a -> 'a j = <fun>
val k : 'a -> 'a k = <fun>
# k ();;
- : unit k =
(((((((((((((((((((((((((((((((((), ()), ((), ())), (((), ()), ((), ()))),
                             ((((), ()), ((), ())), (((), ()), ((), ())))),
                            (((((), ()), ((), ())), (((), ()), ((), ()))),
                             ((((), ()), ((), ())), (((), ()), ((), ()))))),
                           ((((((), ()), ((), ())), (((), ()), ((), ()))),
                             ((((), ()), ((), ())), (((), ()), ((), ())))),
                            (((((), ()), ((), ())), (((), ()), ((), ()))),
                             ((((), ()), ((), ())), (((), ()), ((), ())))))),
                          ((...), ...)),
                         ...),
                        ...),
                       ...),
                      ...),
                     ...),
                    ...),
                   ...),
                  ...),
                 ...),
                ...),
               ...),
              ...),
             ...),
            ...),
           ...),
          ...),
         ...),
        ...),
       ...),
      ...),
     ...),
    ...),
   ...),
  ...),
 ...)
#

poly

lolcathost% poly
Poly/ML 5.5.2 Release
> type 'a f = 'a * 'a
# type 'a g = 'a f f
# type 'a h = 'a g g
# type 'a i = 'a h h
# type 'a j = 'a i i
# type 'a k = 'a j j
# fun f x : 'a f = (x, x)
# fun g x : 'a g = f (f x)
# fun h x : 'a h = g (g x)
# fun i x : 'a i = h (h x)
# fun j x : 'a j = i (i x)
# fun k x : 'a k = j (j x);
  C-c C-c^CCompilation interrupted