Re: An alternative to possreps
From: Bob Badour <bob_at_badour.net>
Date: Sat, 11 Jun 2011 22:39:24 -0700
Message-ID: <Gd-dnZj8K5ySzGnQnZ2dnUVZ5vudnZ2d_at_giganews.com>
>
> In TTM, a type is just a set of values. Nothing more. No operators
> involved (in the type being what it is, namely just a set of values,
> that is).
Date: Sat, 11 Jun 2011 22:39:24 -0700
Message-ID: <Gd-dnZj8K5ySzGnQnZ2dnUVZ5vudnZ2d_at_giganews.com>
Erwin wrote:
> On 9 jun, 08:28, David BL <davi..._at_iinet.net.au> wrote:
>
>>I agree that update operators are an important consideration.
>>
>>Nevertheless I don't think type systems per se should have anything to
>>do with specifying what update operators are available on variables.
>
> Note that TTM doesn't do any such thing. D&D are quite explicit in
> stating that in fact there is only one update operator : assignment.
>
>
>>I consider a type to be a set of values plus operators on *values* (or >>what Date calls read-only operators).
>
> In TTM, a type is just a set of values. Nothing more. No operators
> involved (in the type being what it is, namely just a set of values,
> that is).
If that is the case, how is it that a subtype has a subset of values and a superset of operations? (An operator is just a symbol representing an operation. It's really "operation" that's important.) Received on Sun Jun 12 2011 - 07:39:24 CEST