RFC: more-promise-methods

[Theodus]

Additional methods for the Promise actor:
https://github.com/ponylang/rfcs/blob/master/text/0035-more-promise-methods.md

[Theodus]

This is blocked due to issues with tuple types. See #1146, #1393, #1496

[jeremyjh]

I'm very new to Pony and probably don't have this signature right but does it make sense to also have a bind or flat_map method for promises?

fun tag flat_map[B: Any #share = A](f: {(val->A): Promise[B]}[A, B] box): Promise[B]

Or, is there a way I can turn a Promise[Promise[A]] into Promise[A] ?

[Theodus]

@jeremyjh I expect that more methods such as flat_map will be added through future RFCs. Currently, the next method acts as "bind".

If you would be interested in starting a discussion about additional methods for the Promise API, then you may write up the RFC with the one linked above as reference. More information about the RFC process can be found here: https://github.com/ponylang/rfcs/blob/master/README.md

[SeanTAllen]

@Theodus once the currently ongoing tuple work gets merged, will this be unblocked?

[Theodus]

@SeanTAllen It should be.

[Theodus]

This has been unblocked by #1937