filter -base +bytestring

filter :: (Char -> Bool) -> ByteString -> ByteString
bytestring Data.ByteString.Char8, bytestring Data.ByteString.Lazy.Char8
O(n) filter, applied to a predicate and a ByteString, returns a ByteString containing those characters that satisfy the predicate.
filter :: (Word8 -> Bool) -> ByteString -> ByteString
bytestring Data.ByteString.Lazy
O(n) filter, applied to a predicate and a ByteString, returns a ByteString containing those characters that satisfy the predicate.
filter :: (Word8 -> Bool) -> ByteString -> ByteString
bytestring Data.ByteString
O(n) filter, applied to a predicate and a ByteString, returns a ByteString containing those characters that satisfy the predicate. This function is subject to array fusion.