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Constructors are not functions
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Date: -- (:)
From: Jon Harrop <jon@f...>
Subject: Re: [Caml-list] Constructors are not functions
On Tuesday 06 October 2009 13:45:04 David Allsopp wrote:
> >   Is there a reason for constructors not to behave like functions? For
> > instance, one cannot make a partial application from a constructor:
>
> This is how SML handles constructors, Xavier explained the reasons he chose
> to depart from this in:
>
> http://caml.inria.fr/pub/ml-archives/caml-list/2001/08/47db53a4b42529708647
>c9e81183598b.en.html
>
> I think it would be possible to simulate the SML behaviour in OCaml using
> camlp4 (if you assume that for [type foo = Bar of int] that future unbound
> references to [bar] are interpreted as [fun x -> bar x] instead of an
> error)

Only if you turned multi-argument type constructors into single-argument ones 
taking a tuple, i.e. type definitions like:

  type t = Bar of int * int

must become:

  type t = Bar of (int * int)

-- 
Dr Jon Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/?e