A Challenge Problem for Promise Designers

Ron Buckton rbuckton at chronicles.org
Mon Apr 29 13:39:17 PDT 2013


> -----Original Message-----
> From: Tab Atkins Jr. [mailto:jackalmage at gmail.com]
> Sent: Monday, April 29, 2013 1:20 PM
> To: Ron Buckton
> Cc: Mark Miller; David Sheets; Mark S. Miller; es-discuss; public-script-
> coord at w3.org; David Bruant; Dean Tribble
> Subject: Re: A Challenge Problem for Promise Designers
> 


> > * Added Future.from to perform explicit assimilation (with only one
> > level of unwrap, as with Future#then)
> 
> Like I said, Domenic says that recursive assimilation is useful, and I'm inclined
> to believe him, as he has a lot more experience in getting arbitrary thenables
> to play nicely together than I do. ^_^

I'll tinker with it and run some tests. 
 
> > * Added Future.isFuture to test for native Futures
> 
> For the purpose of library code, you don't need this - just use "x instanceof
> Future".  Future.isFuture is only useful for the language to define, so that it
> can tell something is a Future cross-frame.

The intent is to eventually have a rough polyfill for ES5 and earlier, so if Future.isFuture becomes part of the spec this would likely match using some kind of pseudo-symbol polyfill. 

> 
> ~TJ

Ron


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