#include "share/atspre_staload.hats"

fn {t1, t2, t3 : t@ype}
compose (f : t2 -<cloref1> t3,
         g : t1 -<cloref1> t2) :<cloref1>
    t1 -<cloref1> t3 =
  lam x => f (g (x))

fn
compose_char2int2double
          (f : int -<cloref1> double,
           g : char -<cloref1> int) :<cloref1>
    char -<cloref1> double =
  compose<char, int, double> (f, g)

implement
main0 () =
  let
    val one_hundred = 100.0
    val char_zero = '0'
    val f = (lam y =<cloref1> add_double_int (one_hundred, y))
    val g = (lam x =<cloref1> char2i x - char2i char_zero)
    val z = compose_char2int2double (f, g) ('5')
    val fg = compose_char2int2double (f, g)
    val w = fg ('7')
  in
    println! (z : double);
    println! (w : double)
  end