The type for Unicode characters.

A value of this type represents a Unicode scalar value which is an integer in the ranges 0x0000...0xD7FF or 0xE000...0x10FFFF.

min is U+0000.

max is U+10FFFF.

bom is U+FEFF, the byte order mark (BOM) character.

• since 4.06

rep is U+FFFD, the replacement character.

• since 4.06

succ u is the scalar value after u in the set of Unicode scalar values.

• raises Invalid_argument

  if u is max.

pred u is the scalar value before u in the set of Unicode scalar values.

• raises Invalid_argument

  if u is min.

is_valid n is true if and only if n is a Unicode scalar value (i.e. in the ranges 0x0000...0xD7FF or 0xE000...0x10FFFF).

of_int i is i as a Unicode character.

• raises Invalid_argument

  if i does not satisfy is_valid.

to_int u is u as an integer.

is_char u is true if and only if u is a latin1 OCaml character.

of_char c is c as a Unicode character.

to_char u is u as an OCaml latin1 character.

• raises Invalid_argument

  if u does not satisfy is_char.

equal u u' is u = u'.

compare u u' is Stdlib.compare u u'.

seeded_hash seed u A seeded hash function with the same output value as Hashtbl.seeded_hash. This function allows this module to be passed as an argument to the functor Hashtbl.MakeSeeded.

• since 5.3

An unseeded hash function with the same output value as Hashtbl.hash. This function allows this module to be passed as an argument to the functor Hashtbl.Make.

• before 5.3

  The hashing algorithm was different. Use Hashtbl.rebuild for stored tables which used this hashing function

The type for UTF decode results. Values of this type represent the result of a Unicode Transformation Format decoding attempt.

utf_decode_is_valid d is true if and only if d holds a valid decode.

utf_decode_uchar d is the Unicode character decoded by d if utf_decode_is_valid d is true and Uchar.rep otherwise.

utf_decode_length d is the number of elements from the source that were consumed by the decode d. This is always strictly positive and smaller or equal to 4. The kind of source elements depends on the actual decoder; for the decoders of the standard library this function always returns a length in bytes.

utf_decode n u is a valid UTF decode for u that consumed n elements from the source for decoding. n must be positive and smaller or equal to 4 (this is not checked by the module).

utf_decode_invalid n is an invalid UTF decode that consumed n elements from the source to error. n must be positive and smaller or equal to 4 (this is not checked by the module). The resulting decode has rep as the decoded Unicode character.

utf_8_decode_length_of_byte byte is the number of bytes, from 1 to max_utf_8_decode_length, that a valid UTF-8 decode starting with byte byte would consume or 0 if byte cannot start a valid decode.

• since 5.4

max_utf_8_decode_length is 4, the maximal number of bytes a valid or invalid UTF-8 decode can consume.

• since 5.4

utf_8_byte_length u is the number of bytes needed to encode u in UTF-8.

utf_16_byte_length u is the number of bytes needed to encode u in UTF-16.