Exponentiation operator: Difference between revisions

It is possible to create a generic exponential. For this, one must know the

multiplication function, and the unit value. Here, the usual fast algorithm is

used.

<lang ocaml>let pow one mul a n = let rec g p x = function 0 -> x | i ->

g (mul p p) (if i mod 2 = 1 then mul p x else x) (i/2) in g a one n;;

pow 1 ( * ) 2 16;; (* 65536 *)

pow 1.0 ( *. ) 2.0 16;; (* 65536. *)

(* pow is not limited to exponentiation *)

pow 0 ( + ) 2 16;; (* 32 *)

pow "" ( ^ ) "abc " 10;; (* "abc abc abc abc abc abc abc abc abc abc " *)

</lang>