Question

I have a very simple question: Given a function accepting a char and returning a string

test :: Char -> [String]

how can one convert the char into a string? I’m confused over the two types.

Answer 1

In Haskell String is an alias for [Char]:

type String = [Char]

If you just want a function that converts a single char to a string you could e.g. do

charToString :: Char -> String
charToString c = [c]

If you prefer pointfree style you could also write

charToString :: Char -> String
charToString = (:[])