1118課題 - wwes @ ウィキ

fun flatten L = foldr (fn (x,xs) => x @ xs) [] L;

• flatten1,2],[1,2,3,4;

val it = [1,2,1,2,3,4] : int list

fun forall f L = foldr (fn(x,xs)=>f x andalso xs) false L;

• forall (fn x => x mod 2 = 0)[2,4,6,8];

val it = true : bool

• forall (fn x => x mod 2 = 0)[1,2,3,4];

val it = false : bool

• forall (fn x => x mod 2 = 0)[];

val it = true : bool