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From: Jon Harrop <jonathandeanharrop@googlemail.com>
To: "'ben kuin'" <benkuin@gmail.com>, <caml-list@inria.fr>
Subject: RE: [Caml-list] from if...else to pattern matching
Date: Sat, 2 Oct 2010 18:54:57 +0100	[thread overview]
Message-ID: <002501cb625a$ee2c4b10$ca84e130$@com> (raw)
In-Reply-To: <AANLkTinpu++qk2A3UYJ-t+==bbmb-CWikmPMTATjasKi@mail.gmail.com>

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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      parent reply	other threads:[~2010-10-02 17:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-02 14:04 ben kuin
2010-10-02 14:22 ` [Caml-list] " Philip
2010-10-02 14:47   ` ben kuin
2010-10-02 16:09     ` Hezekiah M. Carty
2010-10-02 17:54 ` Jon Harrop [this message]

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