When they ask you to choose the programming language you are comfortable with before an interview, is it to ask questions about the programming language or to check how well you code in it?
Like for example, if I don't know what
iterators are in Python but I'm comfortable with Python because of its in-built facilities, should I use Python or not?
I might have studied everything about Haskell for ages but it takes me longer to write code in Haskell (imagine writing an AVL tree in Haskell). Is Haskell a good choice then?