Imitating Scala Futures with Go channels (in Go and Clojure)

Scala's Future abstraction is one of my favourite feature of the language. It's simple, elegant and powerful. I make the beginner's attempt to mimic them in Go in a simplistic domain,
Let's assume we have two functions which will take some time (or http calls that naturally return Futures) and we need to aggregate their results.

The Scala way


The Go way


It's rather clunky compared to Scala's solution. But the main problem is that it's not polymorphic on the types. The same lump of code would need to be redefined every time the function signatures change.

Here is a more generic version below that uses explicit type casting.



Not the nicest code I've ever written. If only Go had generics... Any Golang expert out there who could suggest improvements?

The Clojure Way


Clojure borrowed its go-routine and channels idea from Golang. Yet the difference between the Clojure and Go versions in terms of brevity is striking. It's the result of 3 independent factors. One, Clojure is dynamically typed, hence there is no need to hassle with neither function signatures nor generics, or rather the lack of them. Two, it's a functional language. Maps and list comprehensions are way more terse than Go's for-loops. The third factor is async/go returns a channel containing the result of the function executed. Go needs to create a slice of channels first, loop through the slice of functions, create anonymous functions in go blocks where the function is executed and its result is put on the channel, ....lot's of hassle.

With generics many of Go's problems would go away. Rob Pike explicitly said, no generics, but hopefully someone will just force him or do it himself instead.