On Tue, 2009-03-24 at 18:53 -0400, John Cowan wrote:
> Thomas Lord scripsit:
>
> > Perhaps if I write a Scheme with a thoroughly customizable
> > top-level environment I can support R6 but the thing
> > I'm so supporting ("R6") is not therefore a good
> > definition of Scheme. And perhaps I can similarly
> > support a Scheme in an R6 library - but even then,
> > R6 must be understood as something other than Scheme.
>
> The term "Scheme" has no meaning. (To be precise, it used to have no
> operational meaning; now it has no denotational meaning.)
Where I come from, Scheme is a set of generally
agreeable axioms about a prospective class of
of programming environments. The axioms constructively
imply a denotational semantics but one that explicitly
includes domains for "unspecified" and such. Thus,
it defines a wide range of potential programming
environments that have some shared meaning, but that
can also diverge in interesting ways (e.g., by adding
additional axioms). Furthermore, the same axioms
are easily interpreted as partial models of a wide
variety of highly practical implementation techniques
for real-world programming environments (actual physical
instances). Furthermore, the basis of "general agreement"
about this set of axioms is its (a) minimalism - it has to
be a good basis set for computation in a very broad sense;
(b) practicality - it must, indeed, suggest in its structure
models for a wide range of great implementation techniques;
ideally the minimalism should correspond to simplicity of
implementation in readily perceived ways; (c) resemblance to
the broader family of "Lisp" languages generally, such
as in willingness to use models such as "cons pairs" and
"lambda" and such, even if diverging in wise ways from
earlier lisp traditions.
And we liked it that way.
> But as a pragmaticist, I affirm that a term means whatever its
> effects on the hearer are.
> \
I don't know what that means.
-t
_______________________________________________
r6rs-discuss mailing list
[email protected]
http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
