Step toward linked tasks

chat.py

@@ -1,7 +1,6 @@
 import sys
 import asyncio
 import random
-import threading
 import syndicate
 from syndicate import patterns as P, actor
 from syndicate.schema import simpleChatProtocol, gatekeeper, sturdy, dataspace
@@ -25,29 +24,35 @@ def print(*items):
     _print(*items)
     sys.stdout.flush()
 
-def on_presence(turn, who):
-    print('%s joined' % (who,))
-    return lambda turn: print('%s left' % (who,))
-
 def main_facet(turn, root_facet, ds):
     print('main_facet', ds)
     f = turn._facet
     turn.publish(ds, Present(me))
+
+    def on_presence(turn, who):
+        print('%s joined' % (who,))
+        return lambda turn: print('%s left' % (who,))
     turn.publish(ds, dataspace.Observe(P.rec('Present', P.CAPTURE),
                                        During(turn, on_add = on_presence).ref))
-    turn.publish(ds, dataspace.Observe(P.rec('Says', P.CAPTURE, P.CAPTURE), During(
-        turn,
-        on_msg = lambda turn, who, what: print('%s says %r' % (who, what))).ref))
+
+    def on_says(turn, who, what):
+        print('%s says %r' % (who, what))
+    turn.publish(ds, dataspace.Observe(P.rec('Says', P.CAPTURE, P.CAPTURE),
+                                       During(turn, on_msg = on_says).ref))
 
     loop = asyncio.get_running_loop()
-    def accept_input():
+    async def accept_input():
+        reader = asyncio.StreamReader()
+        print(await loop.connect_read_pipe(lambda: asyncio.StreamReaderProtocol(reader), sys.stdin))
         while True:
-            line = sys.stdin.readline()
+            line = await reader.readline()
+            line = line.decode('utf-8')
             if not line:
                 actor.Turn.external(loop, f, lambda turn: turn.stop(root_facet))
                 break
             actor.Turn.external(loop, f, lambda turn: turn.send(ds, Says(me, line.strip())))
-    threading.Thread(target=accept_input, daemon=True).start()
+    input_task = loop.create_task(accept_input())
+    turn._facet.on_stop(lambda turn: input_task.cancel())
 
 def main(turn):
     root_facet = turn._facet