On Sun, Oct 20, 2019 at 5:15 AM Marc Nieper-Wißkirchen <xxxxxx@nieper-wisskirchen.de> wrote:

 
What I wanted to express is that later
additions to the R7RS-large might make possibly better
abstractions/syntax possible. At least for R7RS-large it does not seem
to make sense to me to restrict ourselves to syntax that can be
portably implemented with `syntax-rules' until we haven't decided on
the macro system of R7RS-large.

I see your point.  But that will be a hard fight.  How would things be better with syntax-case?  (I am asking for instruction, not rhetorically.)
 
> Unfortunately, the Chibi syntax-case layer depends on syntactic closures, 
whereas Chicken and Gauche only provide explicit renaming.  (Syntactic closure support is rare:  MIT, Chibi, Picrin.)

What do you mean by "unfortunately"?

By "unfortunately" I mean that if an implementation of syntax-case could be provided on top of explicit renaming, then the barrier to adopting syntax-case as a standard part of the large language is greatly reduced.
 
 while `syntax-case'
cannot be implemented on top of explicit renaming or syntactic
closures, it can after slight modifications.

Do you mean modifications to syntax-case itself, or to the substrate?  And what would those modifications consist of?  We could standardize slightly different versions of either.




John Cowan          http://vrici.lojban.org/~cowan        xxxxxx@ccil.org
The known is finite, the unknown infinite; intellectually we stand
on an islet in the midst of an illimitable ocean of inexplicability.
Our business in every generation is to reclaim a little more land,
to add something to the extent and the solidity of our possessions.
        --Thomas Henry Huxley