test-a.ss
#lang scheme

(require "views.ss")

(provide make-var make-lam make-app var-view lam-view app-view)

(define-struct term ())
(define-struct (var term) (v))
(define-struct (lam term) (arg body))
(define-struct (app term) (op arg))

(define-view var-view var? (var-v))
(define-view lam-view lam? (lam-arg lam-body))
(define-view app-view app? (app-op app-arg))