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From: Shark8 <onewingedshark@gmail.com>
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Subject: Re: Discriminants of tagged types
Date: Sun, 31 Oct 2010 11:36:37 -0700 (PDT)
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Date: 2010-10-31T11:36:37-07:00
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On Oct 31, 10:20=C2=A0am, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> On 30 Pa=C5=BA, 22:21, "Vinzent Hoefler" <nntp-2010...@t-domaingrabbing.d=
e>
> wrote:
>
> > IMO polymorphism and copy semantics are distinct
> > concepts.
>
> As already said, I've yet to see a convincing example of a type that
> is both justifiably polymorphic and copyable at the same time.
>
> --
> Maciej Sobczak *http://www.inspirel.com

I got one for you; I was using tagged types to implement the typing-
system for a PostScript interpreter. Virtually all PostScript objects
(that is, the things you push onto its stacks) are copyable... and all
the objects have attributes for being 'executable' (though the
execution thereof may be defined as [returning] the value thereof).