Btw, you also CAN return the promise from the function you call:
function doSomethingElse(callback){
var p = promise(callback);
setTimeout(function(){
p(1,2);
}, 1000);
return p;
}
var p = doSomethingElse();
p.finish(function(a,b) { console.log(a, b); });
On Monday, April 1, 2013 11:14:07 AM UTC-4, Paul wrote:
>
> I was trying to do the following:
>
> 1. Read a file from disk
> 2. Cache the results of the file
> 3. Use the cache if it's requested again
>
> Everything worked fine unless I read the file multiple times before the
> first read came back -- in this case, obviously the file would be read from
> disk multiple times because it's not in cache yet.
>
> To get around this problem, I came up with a small implementation of
> promises -- which I will call a "pseudo-promise" because it doesn't do all
> the stuff that a promise normally does. My goal was to allow it to be used
> in combination with normal callback styles.
>
> https://gist.github.com/anonymous/4421563620c1cbbf5503
>
> It got a little bit out of order here: promise.js should be the first file
> you look at -- memoize.js is the implementation of it I used for caching
> files.
>
> Because I wanted to be able to pass the "promise" also be used as a
> callback, I added the finish method directly to the callback function. In
> this respect, it works different than a normal "promise" in that you'll
> pass it to the function you want to use a promise with, instead of having
> the function return a promise.
>
> You can check out promiseTest.js for a simpler example of how it works.
>
> Any feedback would be appreciated.
>
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