Module Uchar

module Uchar: sig .. end

Unicode characters.

Since 4.03

type t

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.

val min : t

min is U+0000.

val max : t

max is U+10FFFF.

val bom : t

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

Since 4.06

val rep : t

rep is U+FFFD, the replacement character.

Since 4.06

val succ : t -> t

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

Raises Invalid_argument if u is Uchar.max.

val pred : t -> t

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

Raises Invalid_argument if u is Uchar.min.

val is_valid : int -> bool

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).

val of_int : int -> t

of_int i is i as a Unicode character.

Raises Invalid_argument if i does not satisfy Uchar.is_valid.

val to_int : t -> int

to_int u is u as an integer.

val is_char : t -> bool

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

val of_char : char -> t

of_char c is c as a Unicode character.

val to_char : t -> char

to_char u is u as an OCaml latin1 character.

Raises Invalid_argument if u does not satisfy Uchar.is_char.

val equal : t -> t -> bool

equal u u' is u = u'.

val compare : t -> t -> int

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

val hash : t -> int

hash u associates a non-negative integer to u.

UTF codecs tools

type utf_decode

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

val utf_decode_is_valid : utf_decode -> bool

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

val utf_decode_uchar : utf_decode -> t

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

val utf_decode_length : utf_decode -> int

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.

val utf_decode : int -> t -> utf_decode

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).

val utf_decode_invalid : int -> utf_decode

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 Uchar.rep as the decoded Unicode character.

val utf_8_byte_length : t -> int

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

val utf_16_byte_length : t -> int

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