Rename call_later() arg when to delay.

pep-3156.txt

@@ -169,7 +169,7 @@ A conforming event loop object has the following methods:
 
   Note: run() blocks until the termination condition is met.
 
-  TBD: run() may need an argument to start some work.
+  TBD: run() may need an argument to start some work?
 
 - TBD: Do we need an API for stopping the event loop, given that we
   have the termination condition?  Is the termination condition
@@ -178,9 +178,9 @@ A conforming event loop object has the following methods:
 - TBD: Do we need an API to run the event loop for a little while
   (e.g.  a single iteration)?  If so, exactly what should it do?
 
-- ``call_later(when, callback, *args)``.  Arrange for
-  ``callback(*args)`` to be called approximately ``when`` seconds in
-  the future, once, unless canceled.  As usual in Python, ``when`` may
+- ``call_later(delay, callback, *args)``.  Arrange for
+  ``callback(*args)`` to be called approximately ``delay`` seconds in
+  the future, once, unless canceled.  As usual in Python, ``delay`` may
   be a floating point number to represent smaller intervals.  Returns
   a ``DelayedCall`` object representing the callback, whose
   ``cancel()`` method can be used to cancel the callback.
@@ -201,6 +201,8 @@ A conforming event loop object has the following methods:
   ``isinstance(callback, DelayedCall)``?  It should silently skip
   a canceled callback.
 
+- TBD: Repeatable timers.
+
 Some methods in the standard conforming interface return Futures:
 
 - ``wrap_future(future)``.  This takes a PEP 3148 Future (i.e., an
@@ -346,7 +348,7 @@ guarantees that ``foo()`` is called before ``bar()``.
 If ``call_soon()`` is used, this guarantee is true even if the system
 clock were to run backwards.  This is also the case for
 ``call_later(0, callback, *args)``.  However, if ``call_later()`` is
-used with a nonzero ``when`` argument, all bets are off if the system
+used with a nonzero delay, all bets are off if the system
 clock were to runs backwards.  (A good event loop implementation
 should use ``time.monotonic()`` to avoid problems when the clock runs
 backward.  See PEP 418.)