src/basic/utf8.h

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <uchar.h>

#include "macro.h"
#include "missing_type.h"

#define UTF8_REPLACEMENT_CHARACTER "\xef\xbf\xbd"
#define UTF8_BYTE_ORDER_MARK "\xef\xbb\xbf"

bool unichar_is_valid(char32_t c);

char *utf8_is_valid_n(const char *str, size_t len_bytes) _pure_;
static inline char *utf8_is_valid(const char *s) {
        return utf8_is_valid_n(s, (size_t) -1);
}
char *ascii_is_valid(const char *s) _pure_;
char *ascii_is_valid_n(const char *str, size_t len);

bool utf8_is_printable_newline(const char* str, size_t length, bool allow_newline) _pure_;
#define utf8_is_printable(str, length) utf8_is_printable_newline(str, length, true)

char *utf8_escape_invalid(const char *s);
char *utf8_escape_non_printable_full(const char *str, size_t console_width);
static inline char *utf8_escape_non_printable(const char *str) {
        return utf8_escape_non_printable_full(str, (size_t) -1);
}

size_t utf8_encode_unichar(char *out_utf8, char32_t g);
size_t utf16_encode_unichar(char16_t *out, char32_t c);

char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */);
char16_t *utf8_to_utf16(const char *s, size_t length);

size_t char16_strlen(const char16_t *s); /* returns the number of 16bit words in the string (not bytes!) */

int utf8_encoded_valid_unichar(const char *str, size_t length);
int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar);

static inline bool utf16_is_surrogate(char16_t c) {
        return c >= 0xd800U && c <= 0xdfffU;
}

static inline bool utf16_is_trailing_surrogate(char16_t c) {
        return c >= 0xdc00U && c <= 0xdfffU;
}

static inline char32_t utf16_surrogate_pair_to_unichar(char16_t lead, char16_t trail) {
        return ((((char32_t) lead - 0xd800U) << 10) + ((char32_t) trail - 0xdc00U) + 0x10000U);
}

size_t utf8_n_codepoints(const char *str);
size_t utf8_console_width(const char *str);