#lang racket

(provide (struct-out const) (struct-out binop) rpn->arith)

;; -------------------------------
;; Wyrazenia w odwr. not. polskiej
;; -------------------------------

(define (rpn-expr? e)
  (and (list? e)
       (pair? e)
       (andmap (lambda (x) (or (number? x) (member x '(+ - * /))))
               e)))

;; ----------------------
;; Wyrazenia arytmetyczne
;; ----------------------

(struct const (val)    #:transparent)
(struct binop (op l r) #:transparent)

(define (arith-expr? e)
  (match e
    [(const n) (number? n)]
    [(binop op l r)
     (and (symbol? op) (arith-expr? l) (arith-expr? r))]
    [_ false]))

;; ----------
;; Kompilacja
;; ----------

(define (rpn->arith e)
  (error "TODO: Uzupelnij tutaj"))

; Mozesz tez dodac jakies procedury pomocnicze i testy