[r6rs-discuss] [Formal] Trivial Enhancement of macros in v5.91: capture-syntax

From: Lynn Winebarger <owinebar>
Date: Tue Nov 28 14:35:49 2006

Quoting David Van Horn <dvanhorn_at_cs.brandeis.edu>:

> AndrevanTonder wrote:
>> Lynn Winebarger wrote:
>>
>>> I agree, those are cool macros. However, they did not do what I want,
>>> which is to deprivilege core forms at the top level.
>>
>> While r5.91rs does not say anything about the toplevel, core forms
>> do not currently have any special privilege. You can replace them
>> at will at the library or script level by using something like
>>
>> (import (except r6rs lambda)
>> (rename trace-library (trace-lambda lambda)))

   Thanks for showing this, Andre.

>
> I think the term "core form" is used incorrectly here. A core form
> is an implementation dependent form that results from the expansion
> process. I believe "syntactic keyword" is the correct term, and the
> point is correct, no syntactic keyword enjoys special privilege.
>
     I used the term "core form" correctly, in that they may only
be accessed through syntactic keywords (and which keywords those
may be is implementation-dependent). One of the problems I'm
having is the fact that there apparently are no REPL semantics.
I'm not sure if I should just wait for the formal comment to
which Will Clinger referred regarding program semantics.
     Making REPL semantics completely implementation-dependent
seems like a bad idea to me. Or must we only program in strongly
regulated namespaces from now on? Or am I off base?

Lynn
Received on Tue Nov 28 2006 - 14:35:21 UTC