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Re: a simple counter-proposal



campbell@xxxxxxxxxxxxxxxxxxxxxxxxxxx wrote:
On Mon, 30 Aug 2004, felix wrote:


campbell@xxxxxxxxxxxxxxxxxxxxxxxxxxx wrote:

   (program (requires srfi-1))
   (display (iota 5))

which retains all existing functionality of SRFI 7 -- the feature
conditionalization -- and all brevity of SRFI 55's REQUIRE-EXTENSION --
it's only a single character longer, in fact --; furthermore, it is
still compatible with module systems such as that of Scheme48, because
the module data -- the configuration language -- is _still_ entirely
disjoint from Scheme, unlike the present SRFI 55's REQUIRE-EXTENSION;
the configuration language is very clearly separated from Scheme in
that the PROGRAM form is the first in the file, and every following S-
expression is Scheme.  I propose that SRFI 55 be revised to define this
amendment/extension to SRFI 7, which I expect will satisfy the demands
in brevity of Felix as well as retain the functionality of SRFIs 0 & 7,
and moreover still be as extremely portable as SRFI 7.

Just one question: what makes

(program (required srfi-1))
(display (iota 5))

more portable (in the sense of being compatible with S48's module system),
than

(require-extension (srfi 1))
(display (iota 55))

???

(provided SRFI-55 is changed in such a way that it's recommended
use is as the first expression in a file)


Felix, I spent a significant portion of my last paragraph there in
answering that question before you even asked it.  The PROGRAM form is
_not_ in Scheme; it's in an _entirely_disjoint_ configuration language.
REQUIRE-EXTENSION as you propose would become a part of the _Scheme_
language; it would essentially extend the <command or definition>
nonterminal in R5RS with a new option.

Yes, so what prevents `require-extension' to be such a disjoint config-language
form? If I understand correctly merely requiring that `require-extension' should
be the first form in the program text (directly, not as an expansion of another
macro) would make it compatible with Scheme48, right?


cheers,
felix