Add is_complete request and reply to messaging infrastructure

IPython/kernel/channels.py

@@ -194,6 +194,7 b' class ShellChannel(ZMQSocketChannel):'
         'history',
         'kernel_info',
         'shutdown',
+        'is_complete',
     ]
 
     def __init__(self, context, session, address):
@@ -396,6 +397,10 b' class ShellChannel(ZMQSocketChannel):'
         self._queue_send(msg)
         return msg['header']['msg_id']
 
+    def is_complete(self, code):
+        msg = self.session.msg('is_complete_request', {'code': code})
+        self._queue_send(msg)
+        return msg['header']['msg_id']
 
 
 class IOPubChannel(ZMQSocketChannel):

IPython/kernel/tests/test_message_spec.py

@@ -160,6 +160,10 b' class KernelInfoReply(Reference):'
     banner = Unicode()
 
 
+class IsCompleteReply(Reference):
+    complete = Bool()
+
+
 # IOPub messages
 
 class ExecuteInput(Reference):
@@ -189,6 +193,7 b' references = {'
     'status' : Status(),
     'complete_reply' : CompleteReply(),
     'kernel_info_reply': KernelInfoReply(),
+    'is_complete_reply': IsCompleteReply(),
     'execute_input' : ExecuteInput(),
     'execute_result' : ExecuteResult(),
     'error' : Error(),
@@ -382,6 +387,12 b' def test_single_payload():'
     next_input_pls = [pl for pl in payload if pl["source"] == "set_next_input"]
     nt.assert_equal(len(next_input_pls), 1)
 
+def test_is_complete():
+    flush_channels()
+    
+    msg_id = KC.is_complete("a = 1")
+    reply = KC.get_shell_msg(timeout=TIMEOUT)
+    validate_message(reply, 'is_complete_reply', msg_id)
 
 # IOPub channel
 

IPython/kernel/zmq/kernelbase.py

@@ -114,7 +114,7 b' class Kernel(Configurable):'
                       'inspect_request', 'history_request',
                       'kernel_info_request',
                       'connect_request', 'shutdown_request',
-                      'apply_request',
+                      'apply_request', 'is_complete_request',
                     ]
         self.shell_handlers = {}
         for msg_type in msg_types:
@@ -479,6 +479,22 b' class Kernel(Configurable):'
         kernel.
         """
         return {'status': 'ok', 'restart': restart}
+    
+    def is_complete_request(self, stream, ident, parent):
+        content = parent['content']
+        code = content['code']
+        
+        reply_content = self.do_is_complete(code)
+        reply_content = json_clean(reply_content)
+        reply_msg = self.session.send(stream, 'is_complete_reply',
+                                           reply_content, parent, ident)
+        self.log.debug("%s", reply_msg)
+
+    def do_is_complete(self, code):
+        """Override in subclasses to find completions.
+        """
+        return {'complete' : True,
+                }
 
     #---------------------------------------------------------------------------
     # Engine methods