--- Revision 386562363634
+++ Revision 376330313937
@@ -1,12 +1,12 @@
 def my_awesome_application(environ):
     # do stuff
-    return b'200 OK', [], ["Hello, World!"]
+    yield b'200 OK', [], ["Hello, World!"]
 
 def my_middelware(app):
     def wrapper(environ):
         # maybe edit environ
         try:
-            status, headers, body = app(environ)
+            status, headers, body = yield app(environ)
             # maybe edit response:
             # body = (piglatin(data) for data in body)
             return status, headers, body
@@ -17,10 +17,13 @@
 
 def my_server(app, httpreq):
     environ = wsgi.make_environ(httpreq)
-    try:
-        status, headers, body = app(environ)
+
+    def process_response(result):
+        status, headers, body = result
         write_headers(httpreq, status, headers)
-        for data in body:
-            write_data(httpreq, data)
-     except:
-         respond_with_500()
+        Coroutine(body, body_trampoline, finish_response)
+
+    def finish_response(result):
+        # cleanup, if any
+
+    Coroutine(app(environ), app_trampoline, process_response)