crook

Author: dvanhorn

iniquity-plus/interp-io.rkt

@@ -5,8 +5,12 @@
 ;; Interpret p with given string as input,
 ;; return value and collected output as string
 (define (interp/io p input)
-  (parameterize ((current-output-port (open-output-string))
-                 (current-input-port  (open-input-string input)))
-      (cons (interp p)
-            (get-output-string (current-output-port)))))
+  (define result (box #f))
+  (define output
+    (with-input-from-string input
+      (λ ()
+        (with-output-to-string
+          (λ ()
+            (set-box! result (interp p)))))))
+  (cons (unbox result) output))
 

knock-plus/interp-io.rkt

@@ -5,8 +5,12 @@
 ;; Interpret p with given string as input,
 ;; return value and collected output as string
 (define (interp/io p input)
-  (parameterize ((current-output-port (open-output-string))
-                 (current-input-port  (open-input-string input)))
-      (cons (interp p)
-            (get-output-string (current-output-port)))))
+  (define result (box #f))
+  (define output
+    (with-input-from-string input
+      (λ ()
+        (with-output-to-string
+          (λ ()
+            (set-box! result (interp p)))))))
+  (cons (unbox result) output))