utils: Type hash->list/ordered.

scribblings/utils.scrbl

@@ -360,6 +360,19 @@ Converts the values of a hash table from lists to sets.
 (ht-values/list->set #hash((a . (1 1))))
 ]}
 
+@defproc[(hash->list/ordered [ht (HashTable a b)])
+			     (Listof (Pairof a b))]{
+
+
+Returns the key-value pairs of a given hash table in the order in which the
+hash table orders them for @racket[hash-map].
+
+@bold{TODO:} Remove after Racket 8.4, in which @racket[hash->list] gets a new
+optional argument @racket[try-order?].
+
+@examples[#:eval utils-evaluator
+(hash->list/ordered #hash((b . 1) (a . 1)))
+]}
 
 @section{Functions and procedures}
 

utils.rkt

@@ -23,7 +23,7 @@
    read-org-variable-mapping unorgv read-symbol-list drop-first-last
    list-sets->list-strings pretty-print-set pretty-print-set-sets
    update-vertices/unweighted update-graph dotit collect-by-key
-   collect-by-key/sets ht-values/list->set)
+   collect-by-key/sets ht-values/list->set hash->list/ordered)
 
   (define-type Variable Symbol)
   (define-type (VariableMapping A) (Immutable-HashTable Variable A))
@@ -419,6 +419,16 @@
     (test-case "ht-values/list->set"
       (check-equal? (ht-values/list->set #hash((a . (1 1))))
                     (hash 'a (set 1)))))
+
+  ;; TODO: Remove after Racket 8.4.
+  (: hash->list/ordered (All (a b) (-> (HashTable a b) (Listof (Pairof a b)))))
+  (define (hash->list/ordered ht)
+    ((inst hash-map a b (Pairof a b)) ht cons #t))
+
+  (module+ test
+    (test-case "hash->list/ordered"
+      (check-equal? (hash->list/ordered #hash((b . 1) (a . 1)))
+                    '((a . 1) (b . 1)))))
   )
 
 (require 'typed)
@@ -428,14 +438,13 @@
          read-org-variable-mapping unorgv read-symbol-list drop-first-last
          list-sets->list-strings pretty-print-set pretty-print-set-sets
          update-vertices/unweighted update-graph dotit collect-by-key
-         collect-by-key/sets ht-values/list->set)
+         collect-by-key/sets ht-values/list->set hash->list/ordered)
 
 ;;; Untyped section.
 
 (provide
  ;; Functions
- (contract-out [hash->list/ordered (-> hash? (listof (cons/c any/c any/c)))]
+ (contract-out [multi-split-at (-> (listof (listof any/c)) number?
-               [multi-split-at (-> (listof (listof any/c)) number?
                                    (values (listof (listof any/c)) (listof (listof any/c))))]
                [lists-transpose (-> (listof (listof any/c)) (listof (listof any/c)))]
                [procedure-fixed-arity? (-> procedure? boolean?)]
@@ -472,16 +481,6 @@
 ;;; Additional list and hash map utilities
 ;;; ======================================
 
-
-;;; Returns the key-value pairs of a given hash table in the order in
-;;; which the hash table orders them for hash-map and hash-for-each.
-(define (hash->list/ordered ht) (hash-map ht cons #t))
-
-(module+ test
-  (test-case "hash->list/ordered"
-    (check-equal? (hash->list/ordered #hash((b . 1) (a . 1)))
-                  '((a . 1) (b . 1)))))
-
 ;;; Given a list of lists, splits every single list at the given
 ;;; position, and then returns two lists: one consisting of the first
 ;;; halves, and the one consisting of the second halves.