Re: Parameterized sorts for LSL!?
To: firstname.lastname@example.org (Gary Leavens)
Subject: Re: Parameterized sorts for LSL!?
Date: Wed, 17 Nov 93 09:48:07 -0800
Delivery-Date: Wed, 17 Nov 93 09:48:10 -0800
In-Reply-To: Message of Wed, 17 Nov 93 10:09:15 CST
Yes, LSL needs parameterized sorts. No, I don't know of anyone who has
committed time to design them. A year or so I designed a "poor man's
version," in which names could have components separated by $, and
components could be substituted separately. The Achilles Heel of this
proposal is non-confluence (the same sequence of components could come from
two very different sequences of substitutions). So I concluded that, at a
minimum, there has to be some sort of bracketing, Set[T], rather than
Set$T. But that's as far as it went at that time, I think.
I didn't understand your remark about parameterized function names: Since
they already contain a full signature (which can often be elided), they are
parameterized by all the types in the signature. Or were you simply
suggesting that parameterized types be allowed in signatures? I agree that
the latter would be essential to any useful design for parameterized sorts.