Uutf is a non-blocking streaming codec to decode and encode the UTF-8,
UTF-16, UTF-16LE and UTF-16BE encoding schemes. It can efficiently
work character by character without blocking on IO. Decoders perform
character position tracking and support newline normalization.

Functions are also provided to fold over the characters of UTF encoded
OCaml string values and to directly encode characters in OCaml
Buffer.t values.