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[Caml-list] Python's yield, Lisp's call-cc or C's setjmp/longjmp in OCaml
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Date: -- (:)
From: Falk Hueffner <falk.hueffner@s...>
Subject: Re: [Caml-list] Python's yield, Lisp's call-cc or C's setjmp/longjmp in OCaml
ijtrotts@ucdavis.edu writes:

> Why not do this:
> 
> # let rec number() =
>    let i=ref(-1) in fun() ->
>     incr i; 
>     !i, if !i mod 2 = 0 then "Even" else "Odd";;
> val number : unit -> unit -> int * string = <fun>
> # let n=number();;
> val n : unit -> int * string = <fun>
> # Array.init 10 (fun _ -> n());;
> - : (int * string) array =
> [|(0, "Even"); (1, "Odd"); (2, "Even"); (3, "Odd"); (4, "Even"); (5, "Odd");
>   (6, "Even"); (7, "Odd"); (8, "Even"); (9, "Odd")|]

This only works for simple examples. Try for example writing a
function which successively yields all possible moves for a chess
board. The "yield" operator really helps there.

-- 
	Falk

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