From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <john.r.harrison@intel.com>
X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr
X-Spam-Level: 
X-Spam-Status: No, score=0.0 required=5.0 tests=AWL autolearn=disabled 
	version=3.1.3
Received: from discorde.inria.fr (discorde.inria.fr [192.93.2.38])
	by yquem.inria.fr (Postfix) with ESMTP id 63B41BC6C
	for <caml-list@yquem.inria.fr>; Sat, 25 Aug 2007 01:32:48 +0200 (CEST)
Received: from mga03.intel.com (mga03.intel.com [143.182.124.21])
	by discorde.inria.fr (8.13.6/8.13.6) with ESMTP id l7ONWjL7006015
	for <caml-list@yquem.inria.fr>; Sat, 25 Aug 2007 01:32:47 +0200
Received: from azsmga001.ch.intel.com ([10.2.17.19])
  by azsmga101.ch.intel.com with ESMTP; 24 Aug 2007 16:32:44 -0700
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="4.19,305,1183359600"; 
   d="scan'208";a="267746666"
Received: from orsmsx334.jf.intel.com ([10.22.226.45])
  by azsmga001.ch.intel.com with ESMTP; 24 Aug 2007 16:32:44 -0700
Received: from orsmsx419.amr.corp.intel.com ([10.22.226.88]) by orsmsx334.jf.intel.com with Microsoft SMTPSVC(6.0.3790.1830);
	 Fri, 24 Aug 2007 16:32:43 -0700
X-MimeOLE: Produced By Microsoft Exchange V6.5
Content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
Subject: RE: [Caml-list] Question on polymorphic typing for curried functions
Date: Fri, 24 Aug 2007 16:32:42 -0700
Message-ID: <509223F0BF55E74FA1247D17207E7A0C01CE4E65@orsmsx419.amr.corp.intel.com>
In-Reply-To: <46CF34DE.301@cs.umn.edu>
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Thread-Topic: [Caml-list] Question on polymorphic typing for curried functions
Thread-Index: Acfmh9ynVlNdFAANRDear/S8kp9jGgAHfO8g
References: <46CF34DE.301@cs.umn.edu>
From: "Harrison, John R" <john.r.harrison@intel.com>
To: "Christopher Kauffman" <kauffman@cs.umn.edu>
Cc: "OCaml" <caml-list@yquem.inria.fr>
X-OriginalArrivalTime: 24 Aug 2007 23:32:43.0852 (UTC) FILETIME=[11F4A0C0:01C7E6A7]
X-Miltered: at discorde with ID 46CF6A9D.002 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)!
X-Spam: no; 0.00; curried:01 curried:01 polymorphism:01 ocaml:01 polymorphism:01 polymorphic:01 polymorphic:01 typing:01 caml-list:01 functions:01 functions:01 imperative:01 variant:02 garrigue:03 garrigue:03 

Hi Chris,

| I am looking for a bit of information on the behavior of
| curried functions wrt polymorphic arguments. For instance, in
| the following example, using a curried function seems to lose
| the nice polymorphism that I desire.

OCaml uses a variant of the so-called "value restriction" to ensure
soundness in the way polymorphism and imperative features interact.
You can find more information in this paper by Jacques Garrigue:

  http://www.math.nagoya-u.ac.jp/~garrigue/papers/morepoly-long.pdf

It can sometimes be annoying and unintuitive (for me anyway) to lose
polymorphism by eta contraction. But this approach is at least
relatively simple and well-understood.

John.