Future(s) for D.

[Sebastiaan Koppe via Digitalmars-d]

On Saturday, 20 June 2015 at 12:35:11 UTC, weaselcat wrote:
> I recently read this facebook post on their future 
> implementation in their Folly library.
>
> https://code.facebook.com/posts/1661982097368498
>
> This made me slightly envious. Thoughts on a D implementation?

After having worked with Observables/RX[1], Futures look kind of 
silly to me. I implemented some of them into D (with the help of 
fibers).

Recently I made a small program that, on a merged pull-request on 
bitbucket, looks if the branch contains fix123, bug-123, etc. and 
toggles the ready-to-review status on the issue-tracker.

This is what the code looks like:

```
bitbucketObservable.filter((PullRequest pr)
     {
         return pr.destination == "master" && pr.type == 
PullRequest.Type.MERGED;
     }).map((PullRequest pr)
     {
         auto r = regex(r"(fix|bug)[\/\-_]*([0-9]+)");
         return match(pr.source, r);
     }).filter((RegexMatch!(string, ThompsonMatcher) m)
     {
         return !m.empty();
     }).map((RegexMatch!(string, ThompsonMatcher) m)
     {
         return m.captures[2].to!int;
     }).concatMap((int bug)
     {
         return getCookie.fork(1).setReadyToReview(bug, "updated 
from D");
     }).subscribe((json)
     {
         writefln("Response from bontq: %s",json);
     },(Exception e)
     {
         writeln("Error: %s",e);
     });
```

[1] https://github.com/Reactive-Extensions/RxJS