Abstract Syntax

(define (make-binop op left right)
  (list left op right))
(define (binop? expression) (pair? expression))
(define (binop.left binop) (first binop))
(define (binop.op binop) (second binop))
(define (binop.right binop) (third binop))

(make-binop '+ 5 10) ==> ?????

Jim Miller