<div dir="ltr">My argument goes like this:<div><br><div> 1. You don't need async/await to write a powerful future type; you can use the underlying threads just as well, i.e. future with async/await is no better than future without. </div><div><br></div><div> 2. Since future is more powerful, thread control, cancel, and timeout, people should be encouraged to use this; instead because async/await are language features they will be presumed, incorrectly, to be the best way, consequently people will get into trouble with deadlocks because they don't have control.</div></div><div><br></div><div> 3. async/await will require some engineering work and will at best make a mild syntax improvement and at worst lead to deadlocks, therefore they just don't carry their weight in terms of useful additions to Swift.</div><div><br></div><div>Therefore, save some engineering effort and just provide a future library.</div><div><br></div><div>To turn the question round another way, in two forms:</div><div><br></div><div> 1. What can async/wait do that a future can't?</div><div><br></div><div> 2. How will future be improved if async/await is added?</div><div><br></div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"> -- Howard.<br></div></div>
<br><div class="gmail_quote">On 26 August 2017 at 02:23, Joe Groff <span dir="ltr"><<a href="mailto:jgroff@apple.com" target="_blank">jgroff@apple.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><span class=""><br><div><blockquote type="cite"><div>On Aug 25, 2017, at 12:34 AM, Howard Lovatt <<a href="mailto:howard.lovatt@gmail.com" target="_blank">howard.lovatt@gmail.com</a>> wrote:</div><br class="m_1547456930512826529Apple-interchange-newline"><div><span style="font-family:Helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline!important"><span class="m_1547456930512826529Apple-converted-space"> </span>In particular a future that is cancellable is more powerful that the proposed async/await.</span></div></blockquote></div><br></span><div>It's not more powerful; the features are to some degree disjoint. You can build a Future abstraction and then use async/await to sugar code that threads computation through futures. Getting back to Jakob's example, someone (maybe the Clang importer, maybe Apple's framework developers in an overlay) will still need to build infrastructure on top of IBActions and other currently ad-hoc signalling mechanisms to integrate them into a more expressive coordination framework.</div><span class="HOEnZb"><font color="#888888"><div><br></div><div>-Joe</div></font></span></div></blockquote></div><br></div>