Per Bothner scripsit:

> Technically, it's well-defined R6RS lexical syntax, but it would be
> horrible style.

Oh, I don't deny it.  But I understood that SRFI 10[789] were meant
to never redefine any construct that has meaning in R6RS.  Therefore,
it can only involve things in braces, or else hitherto unheard-of
#-lexical-macros.  This differentiates them from sweet-expressions, which
are not yet a SRFI, and which *redefine* rather than just extending the
lexical syntax of Scheme.

> (The reader does return a form, just like it does for [e1 e2 ... en],
> but it doesn't seem useful except in expression context.)

Well, you never know.  The proliferation of ",foo" REPL commands
in different REPLs is obviously made more likely because Scheme is
guaranteed to return "(unquote foo)" for it, but surely that was no part
of the intention of the R3RS authors.  In Common Lisp, backquote lexical
syntax returns arbitrary CL code whose value you can't count on.

--
That you can cover for the plentiful            John Cowan
and often gaping errors, misconstruals,         http://www.ccil.org/~cowan
and disinformation in your posts                xxxxxx@ccil.org
through sheer volume -- that is another misconception.  --Mike to Peter