On Wed, Nov 12, 2014 at 3:29 PM, James Long <[email protected]> wrote: > On Wed, Nov 12, 2014 at 6:18 PM, Tab Atkins Jr. <[email protected]> wrote: >> No, you're misunderstanding me, or the way that async stuff works. >> >> Calling an async function returns immediately. The called function >> doesn't actually run until a later turn. If it throws, there's *no >> way*, even theoretically, to throw that error at the call-site, >> because the program counter is already well past that point. >> >> If you want the call-site to throw, then you need the callsite itself >> to be in an async function, and you need to use the "await" >> expression, which pauses execution of the caller until the callee's >> returned promise settles. At that point you can throw the rejection >> value, or return the fulfillment value. > > Trust me in that I've done a lot of async coding and I understand well > how it works. The thing I may not understand fully is the current > async/await spec. > > The difference is what happens with `await`, does it throw or does it > automatically put the error on the promise returned from the async > function. I'm essentially saying it should throw by default and you > need to manually forward it. That's all. It doesn't really break > anything.
Something's still going wrong in your understanding here. "await" *receives* a promise. It doesn't return one. It either returns the fulfillment value or throws the rejection value. The question you're asking doesn't make sense. ~TJ _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
