import Data.Char
import Data.Map

-- return a tuple of words, punctuation
splitUp :: String -> ([String], [String])
splitUp s = (words s, dewords s)
	where dewords s = filter (not . isAlpha) s

-- map: key is word, value is another map: key is second word, val is freq: 1/n
data FreqTable = Map String (Map String Int)

makeTable :: [String] -> FreqTable -> FreqTable
makeTable (wa:wb:ws) table = if (member wa table) 
				then if (member wb (table ! wa))
					then let n = (table ! wa) ! wb
					     in insert wb (n+1) (table ! wa) ! wb
				        else insert wa 1 (table ! wa) ! wb
			        else insert wa (fromlist [(wb, 1)])