Prefixes and suffixes

gistfile1.hs

prefix :: Integer -> String -> [FeatureValue]
prefix n =
  map (flip FeatureValue 1 . printf "prefix(%s)") . prefixes n

suffix :: Integer -> String -> [FeatureValue]
suffix n =
  map (flip FeatureValue 1 . printf "suffix(%s)") . prefixes n . reverse

prefixes :: Integer -> String -> [String]
prefixes n word = do
  n <- [1..n]
  return $ genericTake n word