From e4d469ea951eba9525f3bd9231429d05b3d6a10d Mon Sep 17 00:00:00 2001
From: Enrico Lumetti <enrico.lumetti@gmail.com>
Date: Wed, 10 Aug 2022 23:33:20 +0200
Subject: [PATCH] Fix rvar subtraction, convert tests to rackunit

---
 rvar.rkt      |  1 +
 test-rvar.rkt | 65 ++++++++++++++++++++++++++++++---------------------
 2 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/rvar.rkt b/rvar.rkt
index 121d85d..f837169 100644
--- a/rvar.rkt
+++ b/rvar.rkt
@@ -23,6 +23,7 @@
            [(Var name) (eval-symbol env name)]
            [(Prim 'read '()) (read-fixnum)]
            [(Prim '- (list e)) (fx- 0 ((interp-exp env) e))]
+           [(Prim '- `(,e1 ,e2)) (fx- ((interp-exp env) e1) ((interp-exp env) e2))]
            [(Prim '+ `(,e1 ,e2)) (fx+ ((interp-exp env) e1) ((interp-exp env) e2))]
            [(Let var rexp body)
             (let ([value ((interp-exp env) rexp)])
diff --git a/test-rvar.rkt b/test-rvar.rkt
index 539ecdd..90a198b 100644
--- a/test-rvar.rkt
+++ b/test-rvar.rkt
@@ -1,39 +1,50 @@
 #lang racket
 
-(require "test-util.rkt")
+(provide test-rvar-tests)
+
+(require rackunit)
 (require "rvar.rkt")
 
 (define (interp-exp env e)
   ((send (new interp-RVar-class) interp-exp env) e))
 
-(test-eq
-  (let ([env `((a . 1) (b . 2))])
-    (interp-exp env (Var 'a)))
-  1)
+(define test-rvar-tests
+    (test-suite 
+     "RVar interpretation testsuite"
 
-(test-eq
-  (let ([env `((a . 1) (b . 2))])
-    (interp-exp env (Prim '+ (list (Var 'a) (Int 3)))))
-  4)
+     (check-equal?
+       (let ([env `((a . 1) (b . 2))])
+         (interp-exp env (Var 'a)))
+       1)
 
-(test-eq
-  (let ([env `((a . 1) (b . 2))])
-    (interp-exp env (Prim '- `(,(Int 3)))))
-  -3)
+     (check-equal?
+       (let ([env `((a . 1) (b . 2))])
+         (interp-exp env (Prim '+ (list (Var 'a) (Int 3)))))
+       4)
 
-(test-eq
-  (let ([env `((a . 1) (b . 2))])
-    (interp-exp env (Prim '+ (list (Var 'a) (Prim `- (list (Var 'b)))))))
-  -1)
+     (check-equal?
+       (let ([env `((a . 1) (b . 2))])
+         (interp-exp env (Prim '- `(,(Int 3)))))
+       -3)
 
-(test-eq
-  (interp-exp `() (Let 'a
-                       (Prim '+ (list (Int 1) (Int 2)))
-                       (Prim '+ (list (Var 'a) (Int 3)))))
-  6)
+     (check-equal?
+       (let ([env `((a . 1))])
+         (interp-exp env (Prim '- (list (Int 3) (Var 'a)))))
+       2)
 
-(test-eq
-  (interp-RVar (Program `() (Let 'a
-                                 (Prim '+ (list (Int 1) (Int 2)))
-                                 (Prim '+ (list (Var 'a) (Int 3))))))
-  6)
+     (check-equal?
+       (let ([env `((a . 1) (b . 2))])
+         (interp-exp env (Prim '+ (list (Var 'a) (Prim `- (list (Var 'b)))))))
+       -1)
+
+     (check-equal?
+       (interp-exp `() (Let 'a
+                            (Prim '+ (list (Int 1) (Int 2)))
+                            (Prim '+ (list (Var 'a) (Int 3)))))
+       6)
+
+     (check-equal?
+       (interp-RVar (Program `() (Let 'a
+                                      (Prim '+ (list (Int 1) (Int 2)))
+                                      (Prim '+ (list (Var 'a) (Int 3))))))
+       6)))