Conditionally display reference output

Fixes #2

genericTester.scm

@@ -11,6 +11,7 @@
   ; test-assertion should be a lambda we can pass student-out and reference-out
   ; to. Ex: "(lambda (student reference) (< (abs (- student reference)) 0.0001))
   (define test-assertion (read (current-input-port)))
+  (define show-reference-output (read (current-input-port)))
 
   (if (eq? test-output-transform "")
       (set! test-output-transform (lambda (x) x))
@@ -40,9 +41,10 @@
      (apply (eval test-function (interaction-environment))
            (eval test-arguments (interaction-environment)))))
 
-  ; (display "The solution was: " (current-error-port))
-  ; (display reference-out (current-error-port))
-  ; (newline (current-error-port))
+  (if (eval show-reference-output (interaction-environment))
+      (begin (display "The solution was: " (current-error-port))
+             (display reference-out (current-error-port))
+             (newline (current-error-port))))
 
   ; Ensure only #t or #f is the last line. This may not be the case if there
   ; were calls to the display function in the student code.

genericTester.sh

@@ -5,12 +5,14 @@ PLEDGE="I confirm that my submitted solutions are the result of my own intellect
 
 # Default arguments
 CHECK_PLEDGE=false
+SHOW_REFERENCE_OUTPUT="#f"
 testOutputTransform=${testOutputTransform:-(lambda (x) x)}
 
 # Parse command line flags
 while true; do
   case "$1" in
     --check-pledge ) CHECK_PLEDGE=true; shift ;;
+    --show-reference-output ) SHOW_REFERENCE_OUTPUT="#t"; shift ;;
     * ) break ;;
   esac
 done
@@ -22,7 +24,8 @@ stdinToGenericTester="
   $testFunction\n
   (list $testArguments)\n
   $testOutputTransform\n
-  (lambda (student reference) $testAssertion)\n"
+  (lambda (student reference) $testAssertion)\n
+  $SHOW_REFERENCE_OUTPUT\n"
 RESULT=`echo -e $stdinToGenericTester | plt-r5rs genericTester.scm 2>> DEBUG`
 # Treat the last line of the output as a fake exit status
 EXITSTATUS=`echo "$RESULT" | tail -n 1`