arc.arc.t.old

(mac foo (x) `(let y@ (+ ,x 1) (+ y@ ,x)))
(mac foo-bad (x) `(let y (+ ,x 1) (+ y ,x)))
(test-iso "mac gensyms don't capture variables"
  7
  (let y@ 3 (foo y@)))
(test-iso "mac without gensyms does capture variables"
  8  ; probably not what you want
  (let y 3 (foo-bad y)))