utf8.h

/*
  Basic UTF-8 manipulation routines
  by Jeff Bezanson
  placed in the public domain Fall 2005
  Modifications by Jacob Alexander 2019

  This code is designed to provide the utilities you need to manipulate
  UTF-8 as an internal string encoding. These functions do not perform the
  error checking normally needed when handling UTF-8 data, so if you happen
  to be from the Unicode Consortium you will want to flay me alive.
  I do this because error checking can be performed at the boundaries (I/O),
  with these routines reserved for higher performance on data known to be
  valid.
*/

#pragma once

// ----- System Includes -----



#include <stdint.h>



// ----- Macros -----

/* is c the start of a utf8 sequence? */
#define isutf(c) (((c)&0xC0)!=0x80)



// ----- Functions -----

/* single character to UTF-8 */
int u8_wc_toutf8(char *dest, uint32_t ch);

/* character number to byte offset */
int u8_offset(char *str, int charnum);

/* byte offset to character number */
int u8_charnum(char *s, int offset);

/* return next character, updating an index variable */
uint32_t u8_nextchar(char *s, int *i);

/* move to next character */
void u8_inc(char *s, int *i);

/* move to previous character */
void u8_dec(char *s, int *i);

/* returns length of next utf-8 sequence */
int u8_seqlen(char *s);

/* return a pointer to the first occurrence of ch in s, or NULL if not
   found. character index of found character returned in *charn. */
char *u8_strchr(char *s, uint32_t ch, int *charn);

/* same as the above, but searches a buffer of a given size instead of
   a NUL-terminated string. */
char *u8_memchr(char *s, uint32_t ch, uint32_t sz, int *charn);

/* count the number of characters in a UTF-8 string */
int u8_strlen(char *s);