Futures and Promises are a fantastic abstraction for asynchronous operations which I’ll write about in a future post. In Objective-C I used a version of SHXPromise which worked well for us.

Searching for an equivalent in Swift, I narrowed my choice to:

Library # contributors tests last update? documentation issues resolved
Promise Kit 51 yes < week yes 31 open, 227 closed
Future Kit 9 yes 10 days Some, but limited 3 open, 6 closed
Bright Futures 18 yes & Travis 1 month yes 9 open, 56 closed
Bolts 4 yes & Travis < week yes 1 open, 16 closed

On a purely analytical survey, Promise Kit appears to be the winner.

However looking at the APIs I really liked Bright Futures clear understanding and focus on functional composition which I didn’t see as clearly articulated in other libraries.

My choice was Bright Futures

See also