utils: Reimplement and type in-random.

info.rkt

@@ -6,7 +6,8 @@
                "rackunit-typed"
                "typed-graph"
                "typed-racket-lib"
-               "typed-compose"))
+               "typed-compose"
+               "typed-racket-stream"))
 (define build-deps '("racket-doc"
                      "typed-racket-doc"
                      "sandbox-lib"

scribblings/utils.scrbl

@@ -400,6 +400,33 @@ a couple conversions.
 (lists-transpose '((a b) (1 2 3) (#t)))
 ]}
 
+@defproc*[([(in-random) (Sequenceof Flonum)]
+	   [(in-random [k Integer]) (Sequenceof Nonnegative-Fixnum)]
+	   [(in-random [min Integer] [max Integer]) (Sequenceof Nonnegative-Fixnum)])]{
+
+Generates a stream of (inexact) random numbers.  The meaning of the arguments
+is the same as for the function @racket[random]:
+
+@itemlist[
+
+@item{@racket[(in-random)] — a stream of random inexact numbers between
+0 and 1,}
+
+@item{@racket[(in-random k)] — a stream of random exact integers in the range
+@racket[0] to @racket[k]-1.}
+
+@item{@racket[(in-random min max)] — a stream of random exact integers the
+range @racket[min] to @racket[max]-1.}
+
+]
+
+@examples[#:eval utils-evaluator
+(require typed/racket/stream)
+(stream->list (stream-take (in-random) 5))
+(stream->list (stream-take (in-random 10) 5))
+(stream->list (stream-take (in-random 5 10) 5))
+]}
+
 @section{Functions and procedures}
 
 @section{Randomness}

utils.rkt

@@ -11,7 +11,7 @@
 ;;; Typed section.
 
 (module typed typed/racket
-  (require typed/graph typed/rackunit typed-compose
+  (require typed/graph typed/rackunit typed-compose typed/racket/stream
            (for-syntax syntax/parse racket/list))
 
   (provide
@@ -24,7 +24,7 @@
    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 hash->list/ordered
-   multi-split-at lists-transpose)
+   multi-split-at lists-transpose in-random)
 
   (define-type Variable Symbol)
   (define-type (VariableMapping A) (Immutable-HashTable Variable A))
@@ -454,6 +454,35 @@
   (module+ test
   (test-case "lists-transpose"
     (check-equal? (lists-transpose '((1 2) (a b))) '((1 a) (2 b)))))
+
+  (: in-random (case->
+              (-> (Sequenceof Flonum))
+              (-> Integer (Sequenceof Nonnegative-Fixnum))
+              (-> Integer Integer (Sequenceof Nonnegative-Fixnum))))
+  (define in-random
+    (case-lambda
+      [() (stream-cons (random) (in-random))]
+      [(k) (stream-cons (random k) (in-random k))]
+      [(min max) (stream-cons (random min max) (in-random min max))]))
+
+  (module+ test
+    (test-case "in-random"
+      (random-seed 1)
+      (check-equal? (stream->list (stream-take (in-random 100) 10))
+                    '(50 84 10 99 94 88 43 41 63 50))
+      (check-equal? (stream->list (stream-take (in-random 50 100) 10))
+                    '(57 98 82 83 61 53 73 82 50 80))
+      (check-equal? (stream->list (stream-take (in-random) 10))
+                    '(0.2718099186980313
+                      0.7319496826374751
+                      0.17365244033739616
+                      0.5593031443038616
+                      0.3345256691289459
+                      0.9845704615094365
+                      0.05753824253751768
+                      0.22552976312818723
+                      0.21646500425988832
+                      0.15188352823997242))))
   )
 
 (require 'typed)
@@ -464,17 +493,13 @@
          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 hash->list/ordered
-         multi-split-at lists-transpose)
+         multi-split-at lists-transpose in-random)
 
 ;;; Untyped section.
 
 (provide
  ;; Functions
- (contract-out [in-random (case-> (-> (stream/c (and/c real? inexact? (>/c 0) (</c 1))))
+ (contract-out [cartesian-product/stream (->* () #:rest (listof stream?) stream?)]
-                                  (-> (integer-in 1 4294967087) (stream/c exact-nonnegative-integer?))
-                                  (-> exact-integer? (integer-in 1 4294967087)
-                                      (stream/c exact-nonnegative-integer?)))]
-               [cartesian-product/stream (->* () #:rest (listof stream?) stream?)]
                [boolean-power (-> number? (listof (listof boolean?)))]
                [boolean-power/stream (-> number? (stream/c (listof boolean?)))]
                [any->01 (-> any/c (or/c 0 1))]
@@ -499,47 +524,6 @@
         (cons/c key-contract val-contract)))
 
 
-;;; ==========
-;;; Randomness
-;;; ==========
-
-;;; Generates a stream of inexact random numbers.  The meaning of the
-;;; arguments is the same as for the function random:
-;;;
-;;; (in-randoms k) — a sequence of random exact integers in the range
-;;; 0 to k-1.
-;;;
-;;; (in-randoms min max) — a sequence of random exact integers the
-;;; range min to max-1.
-;;;
-;;; (in-randoms) — a sequence of random inexact numbers between
-;;; 0 and 1.
-(define in-random
-  (case-lambda
-    [() (for/stream ([i (in-naturals)]) (random))]
-    [(k) (for/stream ([i (in-naturals)]) (random k))]
-    [(min max) (for/stream ([i (in-naturals)]) (random min max))]))
-
-(module+ test
-  (test-case "in-random"
-    (random-seed 0)
-    (check-equal? (stream->list (stream-take (in-random 100) 10))
-                  '(85 65 20 40 89 45 54 38 26 62))
-    (check-equal? (stream->list (stream-take (in-random 50 100) 10))
-                  '(75 59 82 85 61 85 59 64 75 53))
-    (check-equal? (stream->list (stream-take (in-random) 10))
-                  '(0.1656109603231493
-                    0.9680391127132195
-                    0.051518813640790355
-                    0.755901955353936
-                    0.5923534604277275
-                    0.5513340634474264
-                    0.7022057040731392
-                    0.48375400938578744
-                    0.7538961707172924
-                    0.01828428516237329))))
-
-
 ;;; ===========================
 ;;; Additional stream utilities
 ;;; ===========================