As someone who wrote scala and elixir for a few years and recently switched to a Go job I also dearly missed map and filter. However, people tend to loop unnecessarily often when it's so easy.

Say you have a list of classes and want to pull out certain fields. With immutability as default and easy map functions many people write something like this:

a = my list.map(e => e.foo)

b = mylist.map(e => e.bar)

This may or may not matter performance wise but I think Go has a strong culture of of making something like this easy vs writing a for loop that does everything in one go.

Yes, succinctness is almost never in Go's favor.

So you just want implicit returns?

I want to be able to define generics on methods, not just functions.