Re: reference initialization

[Daniel de Rauglaudre <daniel.de_rauglaudre@inria.fr>]

On Thu, May 11, 2000 at 02:59:16PM -0400, Hongwei Xi wrote:

> I want to combine two arrays into one. Here is the code in OCaml.
>  ...

Simple (library) solution:
=======================
let combine_arrays a b =
  let alen = Array.length a in
  let blen = Array.length b in
  Array.init (alen + blen)
    (fun i -> if i < alen then a.(i) else b.(i - alen))
=======================

Simple (custom) solution:
=======================
let combine_arrays a b =
  let alen = Array.length a in
  let blen = Array.length b in
  if alen = 0 && blen = 0 then [| |]
  else
    let c = Array.make (alen + blen) (if alen = 0 then b.(0) else a.(0)) in
    in begin
      for i = 0 to alen - 1 do
	c.(i) <- a.(i)
      done;
      for i = 0 to blen -1 do
	c.(alen + i) <- b.(i)
      done
    end
=======================

Dirty solution (don't tell them I told you):
=======================
let combine_arrays a b =
  let alen = Array.length a in
  let blen = Array.length b in
  let c = Array.make (alen + blen) (Obj.magic 0)
  in begin
    for i = 0 to alen - 1 do
      c.(i) <- a.(i)
    done;
    for i = 0 to blen -1 do
      c.(alen + i) <- b.(i)
    done
  end
=======================

-- 
Daniel de RAUGLAUDRE
daniel.de_rauglaudre@inria.fr
http://cristal.inria.fr/~ddr/