[Zababa]

https://github.com/golang/go/issues/61405#issuecomment-16388...:

> Can you provide more motivation for range over functions?

> If the results can be generated one at a time, then a representation that allows iterating over them scales better than returning an entire slice. We do not have a standard signature for functions that represent this iteration. Adding support for functions in range would both define a standard signature and provide a real benefit that would encourage its use.

> There are also functions we were reluctant to provide in slices form that probably deserve to be added in iterator form. For example, there should be a strings.Lines(text) that iterates over the lines in a text.