SICP 問題 5.09

;; 演算はレジスタと定数にだけ使えるという条件を強要する．
(define (make-operation-exp exp machine labels operations)
  (let ((op (lookup-prim (operation-exp-op exp) operations))
        (aprocs
         (map (lambda (e)
                (if (label-exp? e)
                    (error "Operation can be used only with registers and constants -- ASSEMBLE" e)
                    (make-primitive-exp e machine labels)))
              (operation-exp-operands exp))))
    (lambda ()
      (apply op (map (lambda (p) (p)) aprocs)))))