¯\_(ツ)_/¯ depends on your code editor and your tooling.
In strongly typed functional languages (Haskell, MLs), you don’t even use OO syntax. Instead you pass your objects into functions. E.g. in Haskell:
writeToFile file data
So the topic of the question does not really apply to functional languages. Personally I gave up on auto-complete with Haskell a long time ago, and it hasn’t been a difficult adjustment. Writing Haskell is still way more pleasant than C++.
In strongly typed functional languages (Haskell, MLs), you don’t even use OO syntax. Instead you pass your objects into functions. E.g. in Haskell:
So the topic of the question does not really apply to functional languages. Personally I gave up on auto-complete with Haskell a long time ago, and it hasn’t been a difficult adjustment. Writing Haskell is still way more pleasant than C++.