将3参数函数映射到Haskell中的列表

Question

The map function works fine on really easy functions that take no arguments like *7 to every element in a list of Ints.

But say I made a custom function that takes a Char, String and Int and then returns a Char and I wanted to apply this function to a list of Chars ie a String to get a String back after applying the other function to each Char? When I try this all I get is error messages?

Answer 1

Put your Char argument to the last position:

foo :: String -> Int -> Char -> Char
foo str num c = c

bar = map (foo str num)

But we really need some more information from your side to help you better. Can you add the code you tried to write to your question?