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Re: [Scheme-reports] ANN: first draft of R7RS small language available

An hour ago, Andre van Tonder wrote:
> On Fri, 29 Apr 2011, John Cowan wrote:
> >> WG2 will have explicit renaming only.
> >
> > If you're curious: explicit renaming was voted up 4-0; syntactic
> > closures voted down 1-3; and syntax-case tied with 3-3 (with one
> > vote for sending it to a future WG), which means it failed.  There
> > were 11 WG members at the time, of which 2 did not vote at all.
> I hope the committee took into account that for systems like Racket
> and Chez that are based on a native psyntax-type macro
> implementation, providing ER macros would adversely affect the
> complexity class of such macros, because in these systems an extra
> code walk is necessary to fully unwrap each input to the ER
> transformer.

It's more than that for Racket, since all expressions are wrapped, and
an implementation of a macro transformer that deals with just plain
lists means that function application (`#%app', an important Racket
feature) becomes unhygienic.

(Obviously there's the question of "how can anyone sane suggest a
system with several different function applications".  Racket has
several answers to that in the form of features that would be
otherwise impossible.)

          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                    http://barzilay.org/                   Maze is Life!

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