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Date: Mon, 31 May 2010 11:43:43 -0400
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Subject: Re: [Caml-list] Why is this allowed?
From: Till Varoquaux <till@pps.jussieu.fr>
To: Jacques Carette <carette@mcmaster.ca>
Cc: caml-list@inria.fr
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X-Spam: no; 0.00; afaik:01 foo:01 struct:01 foo:01 struct:01 metaocaml:01 beginner's:01 ocaml:01 bug:01 beginners:01 wrote:01 pps:01 caml-list:01 caml-list:01 jussieu:01 

AFAIK you are allowed to shadow just about anything in
implementations. If you wanted to keep the exact same interface but
retain the ability to avvoid the shadowing issue on the labels you
could do:

module Foo =3D struct
  type t =3D Foo
end
type foo =3D Foo.t =3D Foo

module Foo2 =3D struct
  type t =3D Foo | Bar
end

type foo2 =3D Foo2.t =3D Foo | Bar

HTH,
Till

On Mon, May 31, 2010 at 10:46 AM, Jacques Carette <carette@mcmaster.ca> wro=
te:
> type foo =3D Foo
> let x =3D Foo
>
> type foo2 =3D Foo | Bar
> let y =3D Foo
> let z =3D (x,y) ;;
>
> I thought that re-using of algebraic labels was not allowed - but apparen=
tly
> it is? =C2=A0Note that this means that it is impossible to "text" print s=
uch
> structures and hope to recover them uniquely. =C2=A0This also causes very=
 subtle
> issues when Marshal'ing, and grave issues for code generation [think
> metaocaml].
>
> Jacques
>
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