syntax-rules question...

[Rob Browning]

While working on a srfi-11 implementation for guile, I ran in to a
problem which I asked about on guile-devel, but then realized might be
more appropriate here.

I had presumed that you could use letrec-syntax to define local
transformers that you could then use as helpers in the body of a
define-syntax transformer, but that doesn't seem to work.  I wanted to
see if this was a bug or my misunderstanding.  For example:

  (use-modules (ice-9 syncase))
  (define-syntax foo
    (letrec-syntax ((xxx (syntax-rules () ((xxx bar) bar)))
                    (yyy (syntax-rules () ((yyy bar) (xxx bar)))))
      (syntax-rules ()
        ((foo a b)
         (+ (xxx a)
            (yyy b))))))

  guile> (foo 1 2)
  ERROR: reference to identifier outside its scope xxx
  ABORT: (misc-error)
  guile>

Thanks

-- 
Rob Browning <address@hidden> PGP=E80E0D04F521A094 532B97F5D64E3930