Added Jython solution

Added abstract interface specification.
(Motivation is in the abstract)

pep-0217.txt

@@ -20,6 +20,17 @@ Abstract
     Python, so users will have control over the output from the
     interactive interpreter.
 
+Interface
+
+    The current Python solution has worked for many users, and this
+    should not break it. Therefore, in the default configuration,
+    nothing will change in the REPL loop. To change the way the
+    interpreter prints interactively entered expressions, users
+    will have to rebind sys.displayhook to a callable object.
+    The result of calling this object with the result of the
+    interactively entered expression should be print-able,
+    and this is what will be printed on sys.stdout.
+
 Solution
 
     The bytecode PRINT_EXPR will call sys.displayhook(POP())
@@ -30,16 +41,13 @@ Solution
     def displayhook(o):
         if o is None:
             return
+        __builtin__._ = None
+        print `o`
         __builtin__._ = o
-        print o
 
 Jython Issues
 
-    The author knows too little about Jython, but it is very important
-    to be compatible with it. displayhook will have to be added to sys,
-    but since Jython works with Java bytecodes, the compiler would have
-    to be changed too, or maybe not.
-    Barry?
+    The method Py.printResult will be similarily changed.
 
 
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