open Printf

let _ =
  let values = [1; 2; 3; 4; 5; 6; 7] in

  let vals2 = 
    map values with
      | 1 | 3 | 7 -> 10
      | v when v mod 2 == 0 -> v + 1 
      | v -> v - 1
  in

  let valfmtd = String.concat ", " (map vals2 with v -> sprintf "<%d>" v) in

  let suml, sumsquares, nelem = 
    foldl values from 0.0, 0.0, 0 with 
	(suml0, sumsq0, n), value -> 
	  let fv = float value in 
	  (suml0 +. fv, sumsq0 +. fv *. fv, n + 1) 
  in
  let mean = suml /. float nelem in
  let sdev = sqrt ((sumsquares -. float nelem *. mean *. mean) 
		   /. (float nelem -. 1.0)) in

  let sumr = 
    foldr values from 0.0 with 
	value, sum0 -> (
	  printf "found value = %d, sum0 = %5.2f\n" value sum0;
	  sum0 +. float value
	) 
  in

  printf "%s\n" valfmtd;
  printf "mean: %g, sdev: %g\n" mean sdev;
  printf "sumr: %g\n" sumr;

  iterate values with
    | 1 -> printf "one\n"
    | v when v mod 2 == 0 -> printf "%d is even\n" v
    | v -> printf "%d is odd\n" v