[pacman-dev] [PATCH v2 3/7] Update the event callback

Allan McRae allan at archlinux.org
Fri Jan 17 06:55:18 EST 2014

On 16/01/14 02:02, Simon Gomizelj wrote:
> I'm not the biggest fan how the casting is working here. We have various
> different structures we can send through now but they all need to be cast
> down and then manually cast back up. I think I'd rather have the base
> structure done as union then.
> But if we're going this far, why now consider going a little farther with
> this.
> The transaction events are handled in a loop but don't seem to require
> anything from the context of the loop. So there is no reason that they
> can't be reimplemented as callbacks.

I'm missing what you mean by this?  What loop?

> And instead of having one callback function which does everything, we can
> introduce one for each of kind of event. The transaction can be seeded with
> a structure pointing to all the various callbacks. Then we start treating a
> transaction like an event loop.
> This would improve type safety since we don't have to cast anything
> anymore. This would improve readability since we don't have to rely on
> casts and heavy switch statements.

The disadvantage of requiring a callback for each event type is that it
requires a callback for each event type...   At the moment, a new
frontend can just start providing a dummy event callback function and
gradually deal with the callbacks rather than having to provide many
functions immediately.

> Just an idea. Back on topic, I do like this change.

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