[r6rs-discuss] Interpreters need not apply?

[Aubrey Jaffer]

 | Date: Wed, 7 Mar 2007 14:31:27 -0500 (EST)
 | From: AndrevanTonder <andre at het.brown.edu>
 | 
 | ... let's consider a toplevel LETREC expression.  I claim (and this
 | is now a modified claim) that various r5rs interpreters will expand
 | such an expression fully before attempting to evaluate it.

(letrec ((a (macro-a)) (b (macro-b)))
  (if a b (macro-c)))

SCM will expand macro-a; then evaluate it; then expand macro-b; then
evaluate it; and expand macro-c only if `a' is bound to #f.