kunishi

datatype ('label) tree = 
  Node of 'label * 'label tree list;

fun sum(Node(a, nil)) = a
  | sum(Node(a, t::ts)) = sum(t) + sum(Node(a, ts));

kunishi

fun swap nil = nil
 |  swap [x] = [x]
 |  swap (x::y::zs) = y::x::(swap zs);

kunishi

fun swapNeighbor(nil) = nil
|   swapNeighbor(x::nil) = x::nil
|   swapNeighbor(x::y::zs) = y::x::swapNeighbor(zs);

kunishi

fun testZero(0) = print("zero\n")
|   testZero(_) = print("not zero\n");

kunishi

fun trap(a, b, n, F) = 
    if n <= 0 orelse b-a <= 0.0 then 0.0
    else
	let
	    val delta = (b-a)/real(n)
	in
	    delta * (F(a) + F(a+delta))/2.0 +
		     trap(a+delta, b, n-1, F)
	end;

kunishi

fun square(x:real) = x*x;
fun plus(x:real, y) = x+y;
fun length(nil) = 0.0
  | length(x::xs) = 1.0 + length(xs);
fun variance(L) =
    let
	val n = length(L)
    in
	reduce(plus, map(square, L))/n -
	square(reduce(plus, L)/n)

kunishi

val sqrt = Math.sqrt;

fun vec_length(nil) = nil
 |  vec_length((x, y)::zs) = sqrt(x * x + y * y)::vec_length(zs);

kunishi

val sqrt = Math.sqrt;

fun simpleMap(f, nil) = nil
 |  simpleMap(f, x::xs) = f(x) :: simpleMap(f, xs);

fun vec_length(L) = simpleMap(fn (x, y) => sqrt(x * x + y * y), L);

kunishi

(define factorial
  (lambda (n)
    (if (= n 0)
	1
	(* n (factorial (- n 1))))))

kunishi

fun remove_a_stone vec i =
    let
	open VectorSlice
	val size = Vector.length vec - 1
	val newvec = 
	    if i = 0 then vector (slice (vec, 1, SOME size))
	    else if i = size then vector (slice (vec, 0, SOME size))
	    else concat [slice (vec, 0, SOME i),
			 slice (vec, i+1, SOME (size-i))]
    in