Haskell List of lists operations

Question

I'm trying to traverse through a list of lists and perform an operation on each list.

If I have a list like

[[("vT",T),("vF",T)],[("vT",T),("vF",F)],[("vT",F),("vF",T)],[("vT",T),("vF",M)],[("vT",M),("vF",T)],[("vT",M),("vF",M)],[("vT",F),("vF",F)],[("vT",F),("vF",M)],[("vT",M),("vF",F)]]

How can I create a function that sets an x = [("vT",T),("vF",T)] , so that I can use this x to perform an operation, and then set x = [("vT",T),("vF",F)] and so on and then have the answer of each returned in a list?

Answer 1

You can use map to apply a function to each element of a list - here's a complete example:

data Tribool = T | F | M deriving Show

my_data = [
    [("vT",T),("vF",T)],
    [("vT",T),("vF",F)],
    [("vT",F),("vF",T)],
    [("vT",T),("vF",M)],
    [("vT",M),("vF",T)],
    [("vT",M),("vF",M)],
    [("vT",F),("vF",F)],
    [("vT",F),("vF",M)],
    [("vT",M),("vF",F)]
  ]

f x = reverse x -- example function

processed_data = map f my_data