[Haskell-cafe] Efficient M to N conversion on fusion?

[iquiw]

Hi,

Is there any efficient way to convert M-length ByteString, Text or
Vector into N-length one?

For example,
 (a) converting byte array into array of their hex representations.
("abc" => "616263")
 (b) escaping some specific characters in string. ("a\bc" => "a\\bc")

The only way I found is to use concatMap...

Thanks,
iquiw