Note that you are using physical equality (==) and not structural equality
(=).

Also, you can always rewrite:

  if <pred> then true else false

more simply as:

  <pred>

> -----Original Message-----
> From: caml-list-bounces@yquem.inria.fr [mailto:caml-list-
> bounces@yquem.inria.fr] On Behalf Of ben kuin
> Sent: 02 October 2010 15:05
> To: caml-list@inria.fr
> Subject: [Caml-list] from if...else to pattern matching
> 
> hi
> I try to transform an if-else clause into pattern matching, I think
> I've tried a lot of approaches, but apperently I'm doing something
> fundemently wrong.
> 
> 
> ~~~~~~~~~
> (** Define behaviors against a constang   'x =< c' with if...else and
> pattern matching.
> I want to see how to match a value against funtion **)
> 
> (* defining a  '=<' operator *)
> let (=<) a b = if a < b then true else if a == b then true else false;;
> 
> let if_test c  =
> if ( 4 =< c )then
>   true
> else
>   false
> ;;
> 
> (* and now use the operator in pattern matching * )
> let match_test c =
>   match  ( _ =< c ) (* pseudocode *)
>     | 4 -> true
>     | _ -> false
> ;;
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> 
> thanks in advance
> ben
> 
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