Why callback handlers?

[ryyppy]

Hey it's me again!
I am just leaving some issues while I am discovering the API and will ask questions which will pop in my head, so everything is in structure ... I have used co and redux-saga quite a lot and was a little bit confused by some things :-)

So here is the most important one... Why does runtime always need two callbacks? Why doesn't it also support Promises?

like this:

const runtime = create();

const successFn = () => {};
const failFn = () => {};

runtime(myGenerator).then(successFn).catch(failFn);

(I am currently working on a pull request to make examples easier to understand btw)

[youknowriad]

Hey! I'm happy to get all this feedback :)

So, about the callback choice instead of promises. Basically, it's a choice due to synchronization errors we could have with promises. More background on this here redux-saga/redux-saga#16 (comment)

And here is an example of a bug that can be caused by a Promise based implementation redux-saga/redux-saga#50

And since I'm using rungen with redux (see redux-rungen), I chose to use callbacks to avoid these synchronization errors (Hard problem to solve).

I've not followed the redux-saga work lately, but I think they managed to get rid of the synchronization issues and still use promises. So, I may be open to using only promises if we can make sure those issues are fixed.