Re: Questions on possreps
Date: Mon, 6 Jun 2011 06:50:24 -0700 (PDT)
Message-ID: <1574535f-bd30-4c65-9ead-6053f02d99ce_at_z13g2000yqg.googlegroups.com>
> Types and hence values and operators are pure mathematical
??????? Not following you at all.
Operators are themselves functions thus relations, thus values !!!
> abstractions. Nested operator invocations provide an entirely
> sufficient means for (logically) representing values.
RELATION PLUS {{1,1,2} {1,2,3} {2,1,3} ...} In what way do you see a "nested operator invocation" being able to, or being needed to, represent the value "INTEGER 1" ?
> I find it
> superfluous to introduce POSSREPs for this purpose (as though
> operators are inadequate!), as well as all the other confusing and
> redundant vernacular: "atomic", "encapsulated", "scalar", "structure",
> "selector", "dummy type" etc. In fact I'm now thinking of POSSREPS as
> merely a peculiar syntactic sugar for declaring operators.
That might not be so terribly wrong, allthoug I personally think this particular "peculiar syntactic sugar" is quite convenient.
> Operators being pure abstractions must be distinguished from any
I don't see your point.
At the very least, I can assure you that D&D are quite aware that
operators as such are "abstract" things, and that there is therefore a
"model vs. implementation" wall between the operators as abstract
mathematical objects (see "operators are relations"), and the
> implementation as executable routines on computers. In fact operators
> are the basis for data representation and not just the basis for
> defining calculations to be executed. It seems as though this former
> perspective was missed when the redundant idea of POSSREPS was
> introduced, and yet strangely was made apparent when each POSSREP
> implicitly declared a kind of operator called a selector.
> Let STRING be a type. POINT and STRING are distinct types. I see no
> need to complicate things by trying to formalise some notion of a
> "possible representation" of POINT involving STRING. All that's
> required are /explicit/ unary operators that map POINT to STRING and
> vice versa.
> It seems awkward to need to specify one subtype relationship in two
> places.
Yes. But see my remark in that other thread about my confusing between the peculiarities of **Tutorial** D, and the Manifesto per se. Received on Mon Jun 06 2011 - 15:50:24 CEST