zyklus zyklus - 6 months ago 11
Javascript Question

Getting a promise's value via yield & co

I'm trying to figure out how to get the value of a promise via

yield
, possibly with "co":

function *(){
var someVar = yield functionThatReturnsAPromise();
}


The called function is not a generator, just a normal function. With the above,
someVar == Promise
, but I want the resolved value. Does co or some other library have a way of doing this?

Answer

Yes, co can do that. You'll have to wrap parent function inside co call:

co(function *(){
    var someVar = yield functionThatReturnsAPromise();
})()

someVar inside will become resolved value. If promise gets rejected, error can be cought with basic try {} catch (e) {} statements.