[r6rs-discuss] [Formal] Version reference syntax is overly complex.

From: Thomas Lord <lord>
Date: Thu, 21 Jun 2007 13:26:52 -0700

Shiro Kawai wrote:


> Even in the above scenario, you can still declare
> that you won't support anything before foo-2.3.


Yes, you can say that, but it is a crazy thing to say.

It may be that, at the time you write your program, it
relies on features only found in foo-2.3 but no prior
version. Yet, backporting is a common occurance.
A year from now, someone may release 1.45 which
contains both desirable features that were dropped
in foo-2, plus a backport of the features your program
needs from foo-2.3. Why should it be necessary to
modify the source of your program just to run it with
library version 1.45?

Linkage, because it is a procedure whose domain
includes all *future* programs, is naturally a
late-bound operation that can pair up any two modules
so long as their import/export contracts conform
to one another. In addition to being late-bound,
linkage should be extensible because we know that managing
execution environments with respect to which library
revisions are present and which should be used when
is an open problem (unlikely, for deep reasons, to
ever have a complete solution). In addition to being
late bound and extensible, linkage should be kept
separate from the source files to which it applies
in support of the separate compilability of modules.

-t
Received on Thu Jun 21 2007 - 16:26:52 UTC