Adding hash table functions to ASL

collects/lang/private/advanced-funs.rkt

@@ -106,4 +106,22 @@
     (set-box! (box any -> void)
               "to update a box")
     (box? (any -> boolean)
-          "to determine if a value is a box"))))
+          "to determine if a value is a box"))
+   
+   ("Hash Tables"
+    ((advanced-make-hash make-hash) ((listof (list X Y)) -> (hash X Y))
+               "to construct a hash table from a list of associations")
+    (hash-set! ((hash X Y) X Y -> void)
+               "to update a hash table with a new association")
+    ((advanced-hash-ref hash-ref) ((hash X Y) X -> Y)
+              "to extract the value associated with a key from a hash table")
+    (hash-has-key? ((hash X Y) X -> boolean)
+                  "to determine if a key is associated with a value in a hash table")
+    (hash-remove! ((hash X Y) X -> void)
+                  "to remove an association from a hash table")
+    (hash-map ((hash X Y) (X Y -> A) -> (listof A))
+              "to construct a new list by applying a function to each association of a hash table")
+    (hash-for-each ((hash X Y) (X Y -> any) -> void)
+                   "to apply a function to each association of a hash table for effect only")
+    (hash? (any -> boolean)
+           "to determine if value is a hash table"))))

collects/lang/private/teachprims.rkt

@@ -345,6 +345,14 @@ namespace.
     (check-last/cycle 'append x)
     (apply append x)))
 
+(define-teach advanced hash-ref
+  (lambda (h k)
+    (hash-ref h k)))
+
+(define-teach advanced make-hash
+  (lambda (a)
+    (make-hash (map (lambda (l) (cons (first l) (second l))) a))))
+
 (provide  
  false?
  beginner-not
@@ -375,6 +383,8 @@ namespace.
  advanced-cons
  advanced-list*
  advanced-append
+ advanced-hash-ref
+ advanced-make-hash
  cyclic-list?)
 
 ;; -----------------------------------------------------------------------------

collects/tests/racket/advanced.rktl

@@ -208,6 +208,31 @@
 (htdp-test #t 'equal~? (equal~?  (shared ([x (cons 10 x)]) x) (shared ([x (cons 10.02 x)]) x) 0.1))
 (htdp-test #f 'equal~? (equal~?  (shared ([x (cons 10 x)]) x) (shared ([x (cons 10.2 x)]) x) 0.1))
 
+(htdp-test 42 'hash-for-each 
+           (local [(define x 0)
+                   (define (f k v) (set! x 42))]
+             (begin (hash-for-each (make-hash (list (list 1 2))) f)
+                    x)))
+(htdp-test #t 'hash-has-key? (hash-has-key? (make-hash (list (list 1 2))) 1))
+(htdp-test #f 'hash-has-key? (hash-has-key? (make-hash (list (list 1 2))) 2))
+(htdp-test (list #f #f) 'hash-map
+           (hash-map (make-hash (list (list 1 #t) (list 2 #t)))
+                     (lambda (k v) (not v))))
+(htdp-test 1 'hash-ref (hash-ref (make-hash (list (list 'a 1))) 'a))
+(htdp-test (list #t #f) 'hash-remove! 
+           (local [(define ht (make-hash (list (list 'a 1))))]
+             (list (hash-has-key? ht 'a)
+                   (begin (hash-remove! ht 'a)
+                          (hash-has-key? ht 'a)))))
+(htdp-test 2 'hash-set!
+           (local [(define ht (make-hash (list (list 'a 1))))]
+             (begin (hash-set! ht 'a 2)
+                    (hash-ref ht 'a))))
+(htdp-test #t 'hash?
+           (hash? (make-hash (list (list 'a 1)))))
+(htdp-test #f 'hash?
+           (hash? 1))
+
 ;; Simulate set! in the repl
 (module my-advanced-module (lib "htdp-advanced.rkt" "lang")
   (define x 10)