Fully composable denodeify

[domenic]

when.js got a method, they call it bind, that creates "fully composable" promise functions from Node functions:

var readFile = whenBind(fs.readFile);
var writeFile = whenBind(fs.writeFile);

writeFile("destination", readFile("source"));

This could be implemented pretty easily by composing Q.promised and Q.nfbind. I propose it as the new implementation of denodeify, which currently in master (never released) is just a synonym for nfbind. Like so:

Q.denodeify = function (nodeFunc) {
  return promised(nfbind(nodeFunc));
};

Sound good?

[ForbesLindesay]

👍 from me

[kriskowal]

How do you feel about making promised implicit to message dispatch?

[ForbesLindesay]

Promised currently causes a few extra calls to nextTick which may be worth attempting to optimize out if we're going to be using it a lot.

I'm broadly in favor of using it everywhere though.

[domenic]

Not sure. Will think about it more. Perf certainly could be an issue.

[kriskowal]

Punting this to a future version. I need to play with the idea of implicit promised in both the general and specific cases.

[domenic]

For reference implicit promised is tracked as #160.

[domenic]

Small back-compat hazard; tagging as such.

[kriskowal]

I believe that generators make this a non-issue. Closing. Please feel free to reopen if you have strong feelings about this direction.