[r6rs-discuss] macroexpand

[Sam TH]

On Fri, 2006-09-22 at 23:06 +0300, Dan Muresan wrote:

> You do realize, of course, that I'm already doing things with define-macro
> /macroexpand that cannot be done without them? And you're saying the
> language should protect me from myself and the things I have accomplished?
> Thanks, but no thanks.

I spend lots of time using `local-expand' in PLT Scheme, which is an
invaluable tool for some macros.  Further, it works correctly for
hygenic macros, which `expand' does not.  So I understand why someone
would want this feature.  

However, it's a complicated extension to the macro system, which would
require careful specification (it's not just exposing the expander).
Therefore, it's appropriate not to specify it right now - there's only
so much that can be done in one revision.

Similarly, an FFI is very important for a programming language, but R6RS
isn't going to specify one.  That isn't a sign the R6RS process is
failing, or that we should adopt a half-baked solution so that we can
specify something now.    

sam th