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Re: A Challenge Problem for Promise Designers

From: Mark Miller <erights@gmail.com>
Date: Sat, 27 Apr 2013 10:20:37 -0700
Message-ID: <CAK5yZYikauicm=J_FJ-JogSARBm6UKqQd1iJm2JjN326ryEfqA@mail.gmail.com>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
Cc: "Mark S. Miller" <erights@google.com>, David Sheets <kosmo.zb@gmail.com>, Ron Buckton <rbuckton@chronicles.org>, David Bruant <bruant.d@gmail.com>, es-discuss <es-discuss@mozilla.org>, "public-script-coord@w3.org" <public-script-coord@w3.org>, Dean Tribble <tribble@e-dean.com>
Sorry, I've been writing code with E style promises for, jeez, over 20
years now. (I suddenly feel very old :( .) I don't remember ever
experiencing the failure you're talking about. Can you give a concrete
example?


On Sat, Apr 27, 2013 at 10:09 AM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:

> On Sat, Apr 27, 2013 at 10:05 AM, Mark S. Miller <erights@google.com>
> wrote:
> > Are you distinguishing "autolifting" vs "lifting"? If so, why do you
> think
> > it is important or desirable to provide a lifting operation (as opposed
> to
> > an autolifting operation)?
>
> Because the "lifting" operation is the monadic lifting operation,
> which you need if you want to write monadic code that works
> predictably.  If all you have is an auto-lifter, your code will
> randomly fail sometimes in mysterious ways, because you're violating
> the monad laws.  (In a distinct, though thematically similar, way to
> how your code sometimes mysteriously fails if you use the Array
> constructor instead of Array.of().)
>
> ~TJ
>



-- 
Text by me above is hereby placed in the public domain

  Cheers,
  --MarkM
Received on Saturday, 27 April 2013 17:21:04 UTC

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