guile-examples/macros/control-flow/or.scm

;; We need to use letrec-syntax here, because inside the
;; definition we use the defined binding already.
(letrec-syntax ([my-or
                 (syntax-rules ()
                   ((my-or)
                    #t)
                   ((my-or exp)
                    exp)
                   ((my-or exp rest ...)
                    (let ((t exp))
                      (if t
                          t
                          (my-or rest ...)))))])
  (my-or #f "rockaway beach"))