generic Boyer-Moore

genBoyerMoore.hs

genericMatchUp :: [ByteString] -> ByteString -> Bool
genericMatchUp pats = isJust . foldr1 (>=>) . fmap strip pats

strip :: ByteString -> ByteString -> Maybe ByteString
strip pat
  | null pat = Just
strip pat = breaker
  where
    !patLen = length pat
    searcher = nonOverlappingIndices pat
    breaker str = case searcher str of
                    []    -> Nothing
                    (i:_) -> Just $ snd $ splitAt (i + patLen) str