Uutf is an non-blocking streaming Unicode codec for OCaml 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.

WWW: http://erratique.ch/software/uutf