[Python-ideas] The async API of the future: Reactors

[Guido van Rossum]

On Sun, Oct 14, 2012 at 8:01 AM, Calvin Spealman <ironfroggy at gmail.com> wrote:
> Why is subclassing a problem? It can be overused, but seems the right
> thing to do in this case. You want a protocol that responds to new data by
> echoing and tells the user when the connection was terminated? It makes
> sense that this is a subclass: a special case of some class that handles the
> base behavior.

I replied to this in detail on the "Twisted and Deferreds" thread in
an exchange. Summary: I'm -0 when it comes to subclassing protocol
classes; -1 on subclassing objects that implement significant
functionality.

> What if this was just an optional way and we could also provide a helper to
> attach handlers to the base class instance without subclassing it? The function
> registering it could take keyword arguments mapping additional event->callbacks
> to the object.

Yeah, there are many APIs that we could offer. We just have to offer
one that's general enough so that people who prefer other styles can
implement their preferred style in a library.

-- 
--Guido van Rossum (python.org/~guido)