Add types for with-output-to-string, open-output-nowhere

Fix time.ss test not to print

svn: r16790

collects/tests/typed-scheme/succeed/time.ss

@@ -1,17 +1,18 @@
 #lang typed-scheme
+(require scheme/port)
 
+(: foo : Number Number -> Number)
+(define (foo x y)
+  (* x y))
 
-
- (: foo : Number Number -> Number)
- (define (foo x y)
-   (* x y))
-
- (: bar : Number -> Number)
- (define (bar c)
-   (: loop : Number Number -> Number)
-   (define (loop n acc)
-     (if (< 0 n)
-         (loop (- n 1) (+ (foo c n) acc))
-         acc))
-   (loop 10000000 0))
- (time (bar 0))
+(: bar : Number -> Number)
+(define (bar c)
+  (: loop : Number Number -> Number)
+  (define (loop n acc)
+    (if (< 0 n)
+	(loop (- n 1) (+ (foo c n) acc))
+	acc))
+  (loop 10000000 0))
+(parameterize ([current-output-port (open-output-nowhere)])
+  (time (bar 0)))
+  

collects/typed-scheme/private/base-env.ss

@@ -733,6 +733,9 @@
 ;; scheme/port
 [port->lines (cl->* (-Input-Port . -> . (-lst -String))
                     (->  (-lst -String)))]
+[with-output-to-string
+  (-> (-> Univ) -String)]
+[open-output-nowhere (-> -Output-Port)]
 
 ;; scheme/path