Remove old assigment from previous years

A1/infix-ae.rkt

@@ -1,70 +0,0 @@
-#lang plait
-
-(define minutes-spent 60)
-
-#| BNF for the AE language:
-   ae: NUMBER
-       | { ae + ae }
-       | { ae - ae }
-       | { ae * ae }
-       | { ae / ae }
-|#
-
-;; AE abstract syntax trees
-(define-type AE
-  [Num (val : Number)]
-  [Add (l : AE) (r : AE)]
-  [Sub (l : AE) (r : AE)]
-  [Mul (l : AE) (r : AE)]
-  [Div (l : AE) (r : AE)])
-
-;; to convert s-expressions into AEs
-(define (parse-sx sx)
-  (let ([rec (lambda (fn sx)
-               (parse-sx (fn (s-exp->list sx))))])
-    (cond
-      [(s-exp-match? `NUMBER sx)
-       (Num (s-exp->number sx))]
-      [(s-exp-match? `(ANY + ANY) sx)
-       (Add (rec first sx) (rec third sx))]
-      [(s-exp-match? `(ANY - ANY) sx)
-       (Sub (rec first sx) (rec third sx))]
-      [(s-exp-match? `(ANY * ANY) sx)
-       (Mul (rec first sx) (rec third sx))]
-      [(s-exp-match? `(ANY / ANY) sx)
-       (Div (rec first sx) (rec third sx))]
-      [else (error 'parse-sx (to-string sx))])))
-
-;; consumes an AE and computes the corresponding number
-(define (eval expr)
-  (type-case AE expr
-    [(Num n)   n]
-    [(Add l r) (+ (eval l) (eval r))]
-    [(Sub l r) (- (eval l) (eval r))]
-    [(Mul l r) (* (eval l) (eval r))]
-    [(Div l r) (if (equal? 0 (eval r))
-                  (cond
-                    [(< 0 (eval l)) +inf.0]
-                    [(> 0 (eval l)) -inf.0]
-                    [else +nan.0])
-                  (/ (eval l) (eval r)))]))
-
-;; evaluate an AE program contained in an s-expr
-(define (run sx)
-  (eval (parse-sx sx)))
-
-;; Basic Parser tests
-(test (run `3)  3) ; Evalutate number by itself
-(test (run `{3 + 4})  7) ; Evaluate two positive integers addition
-(test (run `{{3 - 4} + 7})  6) ; Evaluate subtraction and addition
-(test (run `{8 * 9})  72) ; Evaluate multiplication
-(test (run `{8 / 2})  4) ; Evaluate division
-
-;; Divide by zero tests
-(test (run `{-8 / 0})  -inf.0) ; Negative divide by zero
-(test (run `{8 / {5 - 5}})  +inf.0) ; Positive divide by zero
-(test (run `{1 / {1 / 0}}) 0.0) ; Divide by positive infinity
-(test (run `{0 / 0}) +nan.0) ; Special 0/0 case
-
-;; Parser Errors
-(test/exn (run `{+ 1 1}) "parse") ; Parse error