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Message-ID: <4B7223AA.5020000@frisch.fr>
Date: Wed, 10 Feb 2010 04:10:34 +0100
From: Alain Frisch <alain@frisch.fr>
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To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] The need to specify 'rec' in a recursive function
 defintion
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X-Spam: no; 0.00; frisch:01 frisch:01 recursive:01 defintion:01 guillaume:01 recursion:01 'let:01 rec':01 ocaml:01 polymorphic:01 wrote:01 rec:01 caml-list:01 int:01 int:01 

On 2/10/2010 1:07 AM, Guillaume Yziquel wrote:
> Is it possible to have polymorphic recursion with vanilla 'let rec'
> invocations?

This is something that Jacques recently merged in the current 
development branch. The code below should work with OCaml 3.12.

let length v =
   let rec f : 'a. int -> 'a vec -> int = fun n l -> match l with
      Nil -> n
    | Zero ps -> f (2 * n) ps
    | One (_, ps) -> f (1 + 2 * n) ps
  in
  f 0 v


-- Alain