-- Takes a Column (a vertical slice through an alignment, IOW the residues of
-- each sequence at a given single position) and returns a map of absolute
-- frequency (i.e., counts) of each residue.

colToCountsMap :: Column -> M.Map Residue Int
colToCountsMap col = M.fromListWith (+) [(res, 1) | res <- (T.unpack col)]
colToCountsMap :: Column -> M.Map Residue Int
colToCountsMap col = M.fromListWith (+) [(res, 1) | res <- (T.unpack col)]
colToCountsMap col = M.fromListWith (+) [(res, 1) | res <- (T.unpack col)]