utf8proc.h

/*
 * Copyright (c) 2014-2021 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony
 * Kelman, Scott P. Jones, and other contributors. Copyright (c) 2009 Public
 * Software Group e. V., Berlin, Germany
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/**
 * @mainpage
 *
 * utf8proc is a free/open-source (MIT/expat licensed) C library
 * providing Unicode normalization, case-folding, and other operations
 * for strings in the UTF-8 encoding, supporting up-to-date Unicode versions.
 * See the utf8proc home page (http://julialang.org/utf8proc/)
 * for downloads and other information, or the source code on github
 * (https://github.com/JuliaLang/utf8proc).
 *
 * For the utf8proc API documentation, see: @ref utf8proc.h
 *
 * The features of utf8proc include:
 *
 * - Transformation of strings (@ref utf8proc_map) to:
 *    - decompose (@ref UTF8PROC_DECOMPOSE) or compose (@ref UTF8PROC_COMPOSE)
 * Unicode combining characters
 * (http://en.wikipedia.org/wiki/Combining_character)
 *    - canonicalize Unicode compatibility characters (@ref UTF8PROC_COMPAT)
 *    - strip "ignorable" (@ref UTF8PROC_IGNORE) characters, control characters
 * (@ref UTF8PROC_STRIPCC), or combining characters such as accents (@ref
 * UTF8PROC_STRIPMARK)
 *    - case-folding (@ref UTF8PROC_CASEFOLD)
 * - Unicode normalization: @ref utf8proc_NFD, @ref utf8proc_NFC, @ref
 * utf8proc_NFKD, @ref utf8proc_NFKC
 * - Detecting grapheme boundaries (@ref utf8proc_grapheme_break and @ref
 * UTF8PROC_CHARBOUND)
 * - Character-width computation: @ref utf8proc_charwidth
 * - Classification of characters by Unicode category: @ref utf8proc_category
 * and @ref utf8proc_category_string
 * - Encode (@ref utf8proc_encode_char) and decode (@ref utf8proc_iterate)
 * Unicode codepoints to/from UTF-8.
 */

/** @file */

#ifndef UTF8PROC_H
#define UTF8PROC_H

/** @name API version
 *
 * The utf8proc API version MAJOR.MINOR.PATCH, following
 * semantic-versioning rules (http://semver.org) based on API
 * compatibility.
 *
 * This is also returned at runtime by @ref utf8proc_version; however, the
 * runtime version may append a string like "-dev" to the version number
 * for prerelease versions.
 *
 * @note The shared-library version number in the Makefile
 *       (and CMakeLists.txt, and MANIFEST) may be different,
 *       being based on ABI compatibility rather than API compatibility.
 */
/** @{ */
/** The MAJOR version number (increased when backwards API compatibility is
 * broken). */
#define UTF8PROC_VERSION_MAJOR 2
/** The MINOR version number (increased when new functionality is added in a
 * backwards-compatible manner). */
#define UTF8PROC_VERSION_MINOR 8
/** The PATCH version (increased for fixes that do not change the API). */
#define UTF8PROC_VERSION_PATCH 0
/** @} */

#include <stdlib.h>

#if defined(_MSC_VER) && _MSC_VER < 1800
// MSVC prior to 2013 lacked stdbool.h and inttypes.h
typedef signed char utf8proc_int8_t;
typedef unsigned char utf8proc_uint8_t;
typedef short utf8proc_int16_t;
typedef unsigned short utf8proc_uint16_t;
typedef int utf8proc_int32_t;
typedef unsigned int utf8proc_uint32_t;
#ifdef _WIN64
typedef __int64 utf8proc_ssize_t;
typedef unsigned __int64 utf8proc_size_t;
#else
typedef int utf8proc_ssize_t;
typedef unsigned int utf8proc_size_t;
#endif
#ifndef __cplusplus
// emulate C99 bool
typedef unsigned char utf8proc_bool;
#ifndef __bool_true_false_are_defined
#define false 0
#define true 1
#define __bool_true_false_are_defined 1
#endif
#else
typedef bool utf8proc_bool;
#endif
#else
#include <inttypes.h>
#include <stdbool.h>
#include <stddef.h>

typedef int8_t utf8proc_int8_t;
typedef uint8_t utf8proc_uint8_t;
typedef int16_t utf8proc_int16_t;
typedef uint16_t utf8proc_uint16_t;
typedef int32_t utf8proc_int32_t;
typedef uint32_t utf8proc_uint32_t;
typedef size_t utf8proc_size_t;
typedef ptrdiff_t utf8proc_ssize_t;
typedef bool utf8proc_bool;
#endif
#include <limits.h>

#ifdef UTF8PROC_STATIC
#define UTF8PROC_DLLEXPORT
#else
#ifdef _WIN32
#ifdef UTF8PROC_EXPORTS
#define UTF8PROC_DLLEXPORT __declspec(dllexport)
#else
#define UTF8PROC_DLLEXPORT __declspec(dllimport)
#endif
#elif __GNUC__ >= 4
#define UTF8PROC_DLLEXPORT __attribute__((visibility("default")))
#else
#define UTF8PROC_DLLEXPORT
#endif
#endif

#ifdef __cplusplus
extern "C" {
#endif

/**
 * Option flags used by several functions in the library.
 */
typedef enum
{
    /** The given UTF-8 input is NULL terminated. */
    UTF8PROC_NULLTERM = (1 << 0),
    /** Unicode Versioning Stability has to be respected. */
    UTF8PROC_STABLE = (1 << 1),
    /** Compatibility decomposition (i.e. formatting information is lost). */
    UTF8PROC_COMPAT = (1 << 2),
    /** Return a result with decomposed characters. */
    UTF8PROC_COMPOSE = (1 << 3),
    /** Return a result with decomposed characters. */
    UTF8PROC_DECOMPOSE = (1 << 4),
    /** Strip "default ignorable characters" such as SOFT-HYPHEN or
       ZERO-WIDTH-SPACE. */
    UTF8PROC_IGNORE = (1 << 5),
    /** Return an error, if the input contains unassigned codepoints. */
    UTF8PROC_REJECTNA = (1 << 6),
    /**
     * Indicating that NLF-sequences (LF, CRLF, CR, NEL) are representing a
     * line break, and should be converted to the codepoint for line
     * separation (LS).
     */
    UTF8PROC_NLF2LS = (1 << 7),
    /**
     * Indicating that NLF-sequences are representing a paragraph break, and
     * should be converted to the codepoint for paragraph separation
     * (PS).
     */
    UTF8PROC_NLF2PS = (1 << 8),
    /** Indicating that the meaning of NLF-sequences is unknown. */
    UTF8PROC_NLF2LF = (UTF8PROC_NLF2LS | UTF8PROC_NLF2PS),
    /** Strips and/or convers control characters.
     *
     * NLF-sequences are transformed into space, except if one of the
     * NLF2LS/PS/LF options is given. HorizontalTab (HT) and FormFeed (FF)
     * are treated as a NLF-sequence in this case.  All other control
     * characters are simply removed.
     */
    UTF8PROC_STRIPCC = (1 << 9),
    /**
     * Performs unicode case folding, to be able to do a case-insensitive
     * string comparison.
     */
    UTF8PROC_CASEFOLD = (1 << 10),
    /**
     * Inserts 0xFF bytes at the beginning of each sequence which is
     * representing a single grapheme cluster (see UAX#29).
     */
    UTF8PROC_CHARBOUND = (1 << 11),
    /** Lumps certain characters together.
     *
     * E.g. HYPHEN U+2010 and MINUS U+2212 to ASCII "-". See lump.md for details.
     *
     * If NLF2LF is set, this includes a transformation of paragraph and
     * line separators to ASCII line-feed (LF).
     */
    UTF8PROC_LUMP = (1 << 12),
    /** Strips all character markings.
     *
     * This includes non-spacing, spacing and enclosing (i.e. accents).
     * @note This option works only with @ref UTF8PROC_COMPOSE or
     *       @ref UTF8PROC_DECOMPOSE
     */
    UTF8PROC_STRIPMARK = (1 << 13),
    /**
     * Strip unassigned codepoints.
     */
    UTF8PROC_STRIPNA = (1 << 14),
} utf8proc_option_t;

/** @name Error codes
 * Error codes being returned by almost all functions.
 */
/** @{ */
/** Memory could not be allocated. */
#define UTF8PROC_ERROR_NOMEM -1
/** The given string is too long to be processed. */
#define UTF8PROC_ERROR_OVERFLOW -2
/** The given string is not a legal UTF-8 string. */
#define UTF8PROC_ERROR_INVALIDUTF8 -3
/** The @ref UTF8PROC_REJECTNA flag was set and an unassigned codepoint was
 * found. */
#define UTF8PROC_ERROR_NOTASSIGNED -4
/** Invalid options have been used. */
#define UTF8PROC_ERROR_INVALIDOPTS -5
/** @} */

/* @name Types */

/** Holds the value of a property. */
typedef utf8proc_int16_t utf8proc_propval_t;

/** Struct containing information about a codepoint. */
typedef struct utf8proc_property_struct
{
    /**
     * Unicode category.
     * @see utf8proc_category_t.
     */
    utf8proc_propval_t category;
    utf8proc_propval_t combining_class;
    /**
     * Bidirectional class.
     * @see utf8proc_bidi_class_t.
     */
    utf8proc_propval_t bidi_class;
    /**
     * @anchor Decomposition type.
     * @see utf8proc_decomp_type_t.
     */
    utf8proc_propval_t decomp_type;
    utf8proc_uint16_t decomp_seqindex;
    utf8proc_uint16_t casefold_seqindex;
    utf8proc_uint16_t uppercase_seqindex;
    utf8proc_uint16_t lowercase_seqindex;
    utf8proc_uint16_t titlecase_seqindex;
    utf8proc_uint16_t comb_index;
    unsigned bidi_mirrored : 1;
    unsigned comp_exclusion : 1;
    /**
     * Can this codepoint be ignored?
     *
     * Used by @ref utf8proc_decompose_char when @ref UTF8PROC_IGNORE is
     * passed as an option.
     */
    unsigned ignorable : 1;
    unsigned control_boundary : 1;
    /** The width of the codepoint. */
    unsigned charwidth : 2;
    unsigned pad : 2;
    /**
     * Boundclass.
     * @see utf8proc_boundclass_t.
     */
    unsigned boundclass : 8;
} utf8proc_property_t;

/** Unicode categories. */
typedef enum
{
    UTF8PROC_CATEGORY_CN = 0,  /**< Other, not assigned */
    UTF8PROC_CATEGORY_LU = 1,  /**< Letter, uppercase */
    UTF8PROC_CATEGORY_LL = 2,  /**< Letter, lowercase */
    UTF8PROC_CATEGORY_LT = 3,  /**< Letter, titlecase */
    UTF8PROC_CATEGORY_LM = 4,  /**< Letter, modifier */
    UTF8PROC_CATEGORY_LO = 5,  /**< Letter, other */
    UTF8PROC_CATEGORY_MN = 6,  /**< Mark, nonspacing */
    UTF8PROC_CATEGORY_MC = 7,  /**< Mark, spacing combining */
    UTF8PROC_CATEGORY_ME = 8,  /**< Mark, enclosing */
    UTF8PROC_CATEGORY_ND = 9,  /**< Number, decimal digit */
    UTF8PROC_CATEGORY_NL = 10, /**< Number, letter */
    UTF8PROC_CATEGORY_NO = 11, /**< Number, other */
    UTF8PROC_CATEGORY_PC = 12, /**< Punctuation, connector */
    UTF8PROC_CATEGORY_PD = 13, /**< Punctuation, dash */
    UTF8PROC_CATEGORY_PS = 14, /**< Punctuation, open */
    UTF8PROC_CATEGORY_PE = 15, /**< Punctuation, close */
    UTF8PROC_CATEGORY_PI = 16, /**< Punctuation, initial quote */
    UTF8PROC_CATEGORY_PF = 17, /**< Punctuation, final quote */
    UTF8PROC_CATEGORY_PO = 18, /**< Punctuation, other */
    UTF8PROC_CATEGORY_SM = 19, /**< Symbol, math */
    UTF8PROC_CATEGORY_SC = 20, /**< Symbol, currency */
    UTF8PROC_CATEGORY_SK = 21, /**< Symbol, modifier */
    UTF8PROC_CATEGORY_SO = 22, /**< Symbol, other */
    UTF8PROC_CATEGORY_ZS = 23, /**< Separator, space */
    UTF8PROC_CATEGORY_ZL = 24, /**< Separator, line */
    UTF8PROC_CATEGORY_ZP = 25, /**< Separator, paragraph */
    UTF8PROC_CATEGORY_CC = 26, /**< Other, control */
    UTF8PROC_CATEGORY_CF = 27, /**< Other, format */
    UTF8PROC_CATEGORY_CS = 28, /**< Other, surrogate */
    UTF8PROC_CATEGORY_CO = 29, /**< Other, private use */
} utf8proc_category_t;

/** Bidirectional character classes. */
typedef enum
{
    UTF8PROC_BIDI_CLASS_L   = 1,  /**< Left-to-Right */
    UTF8PROC_BIDI_CLASS_LRE = 2,  /**< Left-to-Right Embedding */
    UTF8PROC_BIDI_CLASS_LRO = 3,  /**< Left-to-Right Override */
    UTF8PROC_BIDI_CLASS_R   = 4,  /**< Right-to-Left */
    UTF8PROC_BIDI_CLASS_AL  = 5,  /**< Right-to-Left Arabic */
    UTF8PROC_BIDI_CLASS_RLE = 6,  /**< Right-to-Left Embedding */
    UTF8PROC_BIDI_CLASS_RLO = 7,  /**< Right-to-Left Override */
    UTF8PROC_BIDI_CLASS_PDF = 8,  /**< Pop Directional Format */
    UTF8PROC_BIDI_CLASS_EN  = 9,  /**< European Number */
    UTF8PROC_BIDI_CLASS_ES  = 10, /**< European Separator */
    UTF8PROC_BIDI_CLASS_ET  = 11, /**< European Number Terminator */
    UTF8PROC_BIDI_CLASS_AN  = 12, /**< Arabic Number */
    UTF8PROC_BIDI_CLASS_CS  = 13, /**< Common Number Separator */
    UTF8PROC_BIDI_CLASS_NSM = 14, /**< Nonspacing Mark */
    UTF8PROC_BIDI_CLASS_BN  = 15, /**< Boundary Neutral */
    UTF8PROC_BIDI_CLASS_B   = 16, /**< Paragraph Separator */
    UTF8PROC_BIDI_CLASS_S   = 17, /**< Segment Separator */
    UTF8PROC_BIDI_CLASS_WS  = 18, /**< Whitespace */
    UTF8PROC_BIDI_CLASS_ON  = 19, /**< Other Neutrals */
    UTF8PROC_BIDI_CLASS_LRI = 20, /**< Left-to-Right Isolate */
    UTF8PROC_BIDI_CLASS_RLI = 21, /**< Right-to-Left Isolate */
    UTF8PROC_BIDI_CLASS_FSI = 22, /**< First Strong Isolate */
    UTF8PROC_BIDI_CLASS_PDI = 23, /**< Pop Directional Isolate */
} utf8proc_bidi_class_t;

/** Decomposition type. */
typedef enum
{
    UTF8PROC_DECOMP_TYPE_FONT     = 1,  /**< Font */
    UTF8PROC_DECOMP_TYPE_NOBREAK  = 2,  /**< Nobreak */
    UTF8PROC_DECOMP_TYPE_INITIAL  = 3,  /**< Initial */
    UTF8PROC_DECOMP_TYPE_MEDIAL   = 4,  /**< Medial */
    UTF8PROC_DECOMP_TYPE_FINAL    = 5,  /**< Final */
    UTF8PROC_DECOMP_TYPE_ISOLATED = 6,  /**< Isolated */
    UTF8PROC_DECOMP_TYPE_CIRCLE   = 7,  /**< Circle */
    UTF8PROC_DECOMP_TYPE_SUPER    = 8,  /**< Super */
    UTF8PROC_DECOMP_TYPE_SUB      = 9,  /**< Sub */
    UTF8PROC_DECOMP_TYPE_VERTICAL = 10, /**< Vertical */
    UTF8PROC_DECOMP_TYPE_WIDE     = 11, /**< Wide */
    UTF8PROC_DECOMP_TYPE_NARROW   = 12, /**< Narrow */
    UTF8PROC_DECOMP_TYPE_SMALL    = 13, /**< Small */
    UTF8PROC_DECOMP_TYPE_SQUARE   = 14, /**< Square */
    UTF8PROC_DECOMP_TYPE_FRACTION = 15, /**< Fraction */
    UTF8PROC_DECOMP_TYPE_COMPAT   = 16, /**< Compat */
} utf8proc_decomp_type_t;

/** Boundclass property. (TR29) */
typedef enum
{
    UTF8PROC_BOUNDCLASS_START              = 0,  /**< Start */
    UTF8PROC_BOUNDCLASS_OTHER              = 1,  /**< Other */
    UTF8PROC_BOUNDCLASS_CR                 = 2,  /**< Cr */
    UTF8PROC_BOUNDCLASS_LF                 = 3,  /**< Lf */
    UTF8PROC_BOUNDCLASS_CONTROL            = 4,  /**< Control */
    UTF8PROC_BOUNDCLASS_EXTEND             = 5,  /**< Extend */
    UTF8PROC_BOUNDCLASS_L                  = 6,  /**< L */
    UTF8PROC_BOUNDCLASS_V                  = 7,  /**< V */
    UTF8PROC_BOUNDCLASS_T                  = 8,  /**< T */
    UTF8PROC_BOUNDCLASS_LV                 = 9,  /**< Lv */
    UTF8PROC_BOUNDCLASS_LVT                = 10, /**< Lvt */
    UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR = 11, /**< Regional indicator */
    UTF8PROC_BOUNDCLASS_SPACINGMARK        = 12, /**< Spacingmark */
    UTF8PROC_BOUNDCLASS_PREPEND            = 13, /**< Prepend */
    UTF8PROC_BOUNDCLASS_ZWJ                = 14, /**< Zero Width Joiner */

    /* the following are no longer used in Unicode 11, but we keep
       the constants here for backward compatibility */
    UTF8PROC_BOUNDCLASS_E_BASE         = 15, /**< Emoji Base */
    UTF8PROC_BOUNDCLASS_E_MODIFIER     = 16, /**< Emoji Modifier */
    UTF8PROC_BOUNDCLASS_GLUE_AFTER_ZWJ = 17, /**< Glue_After_ZWJ */
    UTF8PROC_BOUNDCLASS_E_BASE_GAZ     = 18, /**< E_BASE + GLUE_AFTER_ZJW */

    /* the Extended_Pictographic property is used in the Unicode 11
       grapheme-boundary rules, so we store it in the boundclass field */
    UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC = 19,
    UTF8PROC_BOUNDCLASS_E_ZWG = 20, /* UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC + ZWJ */
} utf8proc_boundclass_t;

/**
 * Function pointer type passed to @ref utf8proc_map_custom and
 * @ref utf8proc_decompose_custom, which is used to specify a user-defined
 * mapping of codepoints to be applied in conjunction with other mappings.
 */
typedef utf8proc_int32_t (*utf8proc_custom_func)(utf8proc_int32_t codepoint, void* data);

/**
 * Array containing the byte lengths of a UTF-8 encoded codepoint based
 * on the first byte.
 */
UTF8PROC_DLLEXPORT extern const utf8proc_int8_t utf8proc_utf8class[256];

/**
 * Returns the utf8proc API version as a string MAJOR.MINOR.PATCH
 * (http://semver.org format), possibly with a "-dev" suffix for
 * development versions.
 */
UTF8PROC_DLLEXPORT const char* utf8proc_version(void);

/**
 * Returns the utf8proc supported Unicode version as a string MAJOR.MINOR.PATCH.
 */
UTF8PROC_DLLEXPORT const char* utf8proc_unicode_version(void);

/**
 * Returns an informative error string for the given utf8proc error code
 * (e.g. the error codes returned by @ref utf8proc_map).
 */
UTF8PROC_DLLEXPORT const char* utf8proc_errmsg(utf8proc_ssize_t errcode);

/**
 * Reads a single codepoint from the UTF-8 sequence being pointed to by `str`.
 * The maximum number of bytes read is `strlen`, unless `strlen` is
 * negative (in which case up to 4 bytes are read).
 *
 * If a valid codepoint could be read, it is stored in the variable
 * pointed to by `codepoint_ref`, otherwise that variable will be set to -1.
 * In case of success, the number of bytes read is returned; otherwise, a
 * negative error code is returned.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_iterate(const utf8proc_uint8_t* str,
                                                     utf8proc_ssize_t strlen,
                                                     utf8proc_int32_t* codepoint_ref);

/**
 * Check if a codepoint is valid (regardless of whether it has been
 * assigned a value by the current Unicode standard).
 *
 * @return 1 if the given `codepoint` is valid and otherwise return 0.
 */
UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_codepoint_valid(utf8proc_int32_t codepoint);

/**
 * Encodes the codepoint as an UTF-8 string in the byte array pointed
 * to by `dst`. This array must be at least 4 bytes long.
 *
 * In case of success the number of bytes written is returned, and
 * otherwise 0 is returned.
 *
 * This function does not check whether `codepoint` is valid Unicode.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_encode_char(utf8proc_int32_t codepoint,
                                                         utf8proc_uint8_t* dst);

/**
 * Look up the properties for a given codepoint.
 *
 * @param codepoint The Unicode codepoint.
 *
 * @returns
 * A pointer to a (constant) struct containing information about
 * the codepoint.
 * @par
 * If the codepoint is unassigned or invalid, a pointer to a special struct is
 * returned in which `category` is 0 (@ref UTF8PROC_CATEGORY_CN).
 */
UTF8PROC_DLLEXPORT const utf8proc_property_t* utf8proc_get_property(utf8proc_int32_t codepoint);

/** Decompose a codepoint into an array of codepoints.
 *
 * @param codepoint the codepoint.
 * @param dst the destination buffer.
 * @param bufsize the size of the destination buffer.
 * @param options one or more of the following flags:
 * - @ref UTF8PROC_REJECTNA  - return an error `codepoint` is unassigned
 * - @ref UTF8PROC_IGNORE    - strip "default ignorable" codepoints
 * - @ref UTF8PROC_CASEFOLD  - apply Unicode casefolding
 * - @ref UTF8PROC_COMPAT    - replace certain codepoints with their
 *                             compatibility decomposition
 * - @ref UTF8PROC_CHARBOUND - insert 0xFF bytes before each grapheme cluster
 * - @ref UTF8PROC_LUMP      - lump certain different codepoints together
 * - @ref UTF8PROC_STRIPMARK - remove all character marks
 * - @ref UTF8PROC_STRIPNA   - remove unassigned codepoints
 * @param last_boundclass
 * Pointer to an integer variable containing
 * the previous codepoint's boundary class if the @ref UTF8PROC_CHARBOUND
 * option is used.  Otherwise, this parameter is ignored.
 *
 * @return
 * In case of success, the number of codepoints written is returned; in case
 * of an error, a negative error code is returned (@ref utf8proc_errmsg).
 * @par
 * If the number of written codepoints would be bigger than `bufsize`, the
 * required buffer size is returned, while the buffer will be overwritten with
 * undefined data.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_char(utf8proc_int32_t codepoint,
                                                            utf8proc_int32_t* dst,
                                                            utf8proc_ssize_t bufsize,
                                                            utf8proc_option_t options,
                                                            int* last_boundclass);

/**
 * The same as @ref utf8proc_decompose_char, but acts on a whole UTF-8
 * string and orders the decomposed sequences correctly.
 *
 * If the @ref UTF8PROC_NULLTERM flag in `options` is set, processing
 * will be stopped, when a NULL byte is encountered, otherwise `strlen`
 * bytes are processed.  The result (in the form of 32-bit unicode
 * codepoints) is written into the buffer being pointed to by
 * `buffer` (which must contain at least `bufsize` entries).  In case of
 * success, the number of codepoints written is returned; in case of an
 * error, a negative error code is returned (@ref utf8proc_errmsg).
 * See @ref utf8proc_decompose_custom to supply additional transformations.
 *
 * If the number of written codepoints would be bigger than `bufsize`, the
 * required buffer size is returned, while the buffer will be overwritten with
 * undefined data.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose(const utf8proc_uint8_t* str,
                                                       utf8proc_ssize_t strlen,
                                                       utf8proc_int32_t* buffer,
                                                       utf8proc_ssize_t bufsize,
                                                       utf8proc_option_t options);

/**
 * The same as @ref utf8proc_decompose, but also takes a `custom_func` mapping
 * function that is called on each codepoint in `str` before any other
 * transformations (along with a `custom_data` pointer that is passed through to
 * `custom_func`). The `custom_func` argument is ignored if it is `NULL`.  See
 * also @ref utf8proc_map_custom.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_custom(const utf8proc_uint8_t* str,
                                                              utf8proc_ssize_t strlen,
                                                              utf8proc_int32_t* buffer,
                                                              utf8proc_ssize_t bufsize,
                                                              utf8proc_option_t options,
                                                              utf8proc_custom_func custom_func,
                                                              void* custom_data);

/**
 * Normalizes the sequence of `length` codepoints pointed to by `buffer`
 * in-place (i.e., the result is also stored in `buffer`).
 *
 * @param buffer the (native-endian UTF-32) unicode codepoints to re-encode.
 * @param length the length (in codepoints) of the buffer.
 * @param options a bitwise or (`|`) of one or more of the following flags:
 * - @ref UTF8PROC_NLF2LS  - convert LF, CRLF, CR and NEL into LS
 * - @ref UTF8PROC_NLF2PS  - convert LF, CRLF, CR and NEL into PS
 * - @ref UTF8PROC_NLF2LF  - convert LF, CRLF, CR and NEL into LF
 * - @ref UTF8PROC_STRIPCC - strip or convert all non-affected control
 * characters
 * - @ref UTF8PROC_COMPOSE - try to combine decomposed codepoints into composite
 *                           codepoints
 * - @ref UTF8PROC_STABLE  - prohibit combining characters that would violate
 *                           the unicode versioning stability
 *
 * @return
 * In case of success, the length (in codepoints) of the normalized UTF-32
 * string is returned; otherwise, a negative error code is returned (@ref
 * utf8proc_errmsg).
 *
 * @warning The entries of the array pointed to by `str` have to be in the
 *          range `0x0000` to `0x10FFFF`. Otherwise, the program might crash!
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_normalize_utf32(utf8proc_int32_t* buffer,
                                                             utf8proc_ssize_t length,
                                                             utf8proc_option_t options);

/**
 * Reencodes the sequence of `length` codepoints pointed to by `buffer`
 * UTF-8 data in-place (i.e., the result is also stored in `buffer`).
 * Can optionally normalize the UTF-32 sequence prior to UTF-8 conversion.
 *
 * @param buffer the (native-endian UTF-32) unicode codepoints to re-encode.
 * @param length the length (in codepoints) of the buffer.
 * @param options a bitwise or (`|`) of one or more of the following flags:
 * - @ref UTF8PROC_NLF2LS  - convert LF, CRLF, CR and NEL into LS
 * - @ref UTF8PROC_NLF2PS  - convert LF, CRLF, CR and NEL into PS
 * - @ref UTF8PROC_NLF2LF  - convert LF, CRLF, CR and NEL into LF
 * - @ref UTF8PROC_STRIPCC - strip or convert all non-affected control
 * characters
 * - @ref UTF8PROC_COMPOSE - try to combine decomposed codepoints into composite
 *                           codepoints
 * - @ref UTF8PROC_STABLE  - prohibit combining characters that would violate
 *                           the unicode versioning stability
 * - @ref UTF8PROC_CHARBOUND - insert 0xFF bytes before each grapheme cluster
 *
 * @return
 * In case of success, the length (in bytes) of the resulting nul-terminated
 * UTF-8 string is returned; otherwise, a negative error code is returned
 * (@ref utf8proc_errmsg).
 *
 * @warning The amount of free space pointed to by `buffer` must
 *          exceed the amount of the input data by one byte, and the
 *          entries of the array pointed to by `str` have to be in the
 *          range `0x0000` to `0x10FFFF`. Otherwise, the program might crash!
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_reencode(utf8proc_int32_t* buffer,
                                                      utf8proc_ssize_t length,
                                                      utf8proc_option_t options);

/**
 * Given a pair of consecutive codepoints, return whether a grapheme break is
 * permitted between them (as defined by the extended grapheme clusters in
 * UAX#29).
 *
 * @param codepoint1 The first codepoint.
 * @param codepoint2 The second codepoint, occurring consecutively after
 * `codepoint1`.
 * @param state Beginning with Version 29 (Unicode 9.0.0), this algorithm
 * requires state to break graphemes. This state can be passed in as a pointer
 *              in the `state` argument and should initially be set to 0. If the
 *              state is not passed in (i.e. a null pointer is passed), UAX#29
 * rules GB10/12/13 which require this state will not be applied, essentially
 *              matching the rules in Unicode 8.0.0.
 *
 * @warning If the state parameter is used, `utf8proc_grapheme_break_stateful`
 * must be called IN ORDER on ALL potential breaks in a string.  However, it is
 * safe to reset the state to zero after a grapheme break.
 */
UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break_stateful(utf8proc_int32_t codepoint1,
                                                                  utf8proc_int32_t codepoint2,
                                                                  utf8proc_int32_t* state);

/**
 * Same as @ref utf8proc_grapheme_break_stateful, except without support for the
 * Unicode 9 additions to the algorithm. Supported for legacy reasons.
 */
UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break(utf8proc_int32_t codepoint1,
                                                         utf8proc_int32_t codepoint2);

/**
 * Given a codepoint `c`, return the codepoint of the corresponding
 * lower-case character, if any; otherwise (if there is no lower-case
 * variant, or if `c` is not a valid codepoint) return `c`.
 */
UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_tolower(utf8proc_int32_t c);

/**
 * Given a codepoint `c`, return the codepoint of the corresponding
 * upper-case character, if any; otherwise (if there is no upper-case
 * variant, or if `c` is not a valid codepoint) return `c`.
 */
UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_toupper(utf8proc_int32_t c);

/**
 * Given a codepoint `c`, return the codepoint of the corresponding
 * title-case character, if any; otherwise (if there is no title-case
 * variant, or if `c` is not a valid codepoint) return `c`.
 */
UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_totitle(utf8proc_int32_t c);

/**
 * Given a codepoint `c`, return `1` if the codepoint corresponds to a
 * lower-case character and `0` otherwise.
 */
UTF8PROC_DLLEXPORT int utf8proc_islower(utf8proc_int32_t c);

/**
 * Given a codepoint `c`, return `1` if the codepoint corresponds to an
 * upper-case character and `0` otherwise.
 */
UTF8PROC_DLLEXPORT int utf8proc_isupper(utf8proc_int32_t c);

/**
 * Given a codepoint, return a character width analogous to
 * `wcwidth(codepoint)`, except that a width of 0 is returned for non-printable
 * codepoints instead of -1 as in `wcwidth`.
 *
 * @note
 * If you want to check for particular types of non-printable characters,
 * (analogous to `isprint` or `iscntrl`), use @ref utf8proc_category. */
UTF8PROC_DLLEXPORT int utf8proc_charwidth(utf8proc_int32_t codepoint);

/**
 * Return the Unicode category for the codepoint (one of the
 * @ref utf8proc_category_t constants.)
 */
UTF8PROC_DLLEXPORT utf8proc_category_t utf8proc_category(utf8proc_int32_t codepoint);

/**
 * Return the two-letter (nul-terminated) Unicode category string for
 * the codepoint (e.g. `"Lu"` or `"Co"`).
 */
UTF8PROC_DLLEXPORT const char* utf8proc_category_string(utf8proc_int32_t codepoint);

/**
 * Maps the given UTF-8 string pointed to by `str` to a new UTF-8
 * string, allocated dynamically by `malloc` and returned via `dstptr`.
 *
 * If the @ref UTF8PROC_NULLTERM flag in the `options` field is set,
 * the length is determined by a NULL terminator, otherwise the
 * parameter `strlen` is evaluated to determine the string length, but
 * in any case the result will be NULL terminated (though it might
 * contain NULL characters with the string if `str` contained NULL
 * characters). Other flags in the `options` field are passed to the
 * functions defined above, and regarded as described.  See also
 * @ref utf8proc_map_custom to supply a custom codepoint transformation.
 *
 * In case of success the length of the new string is returned,
 * otherwise a negative error code is returned.
 *
 * @note The memory of the new UTF-8 string will have been allocated
 * with `malloc`, and should therefore be deallocated with `free`.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map(const utf8proc_uint8_t* str,
                                                 utf8proc_ssize_t strlen,
                                                 utf8proc_uint8_t** dstptr,
                                                 utf8proc_option_t options);

/**
 * Like @ref utf8proc_map, but also takes a `custom_func` mapping function
 * that is called on each codepoint in `str` before any other transformations
 * (along with a `custom_data` pointer that is passed through to `custom_func`).
 * The `custom_func` argument is ignored if it is `NULL`.
 */
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map_custom(const utf8proc_uint8_t* str,
                                                        utf8proc_ssize_t strlen,
                                                        utf8proc_uint8_t** dstptr,
                                                        utf8proc_option_t options,
                                                        utf8proc_custom_func custom_func,
                                                        void* custom_data);

/** @name Unicode normalization
 *
 * Returns a pointer to newly allocated memory of a NFD, NFC, NFKD, NFKC or
 * NFKC_Casefold normalized version of the null-terminated string `str`.  These
 * are shortcuts to calling @ref utf8proc_map with @ref UTF8PROC_NULLTERM
 * combined with @ref UTF8PROC_STABLE and flags indicating the normalization.
 */
/** @{ */
/** NFD normalization (@ref UTF8PROC_DECOMPOSE). */
UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFD(const utf8proc_uint8_t* str);
/** NFC normalization (@ref UTF8PROC_COMPOSE). */
UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFC(const utf8proc_uint8_t* str);
/** NFKD normalization (@ref UTF8PROC_DECOMPOSE and @ref UTF8PROC_COMPAT). */
UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKD(const utf8proc_uint8_t* str);
/** NFKC normalization (@ref UTF8PROC_COMPOSE and @ref UTF8PROC_COMPAT). */
UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKC(const utf8proc_uint8_t* str);
/**
 * NFKC_Casefold normalization (@ref UTF8PROC_COMPOSE and @ref UTF8PROC_COMPAT
 * and @ref UTF8PROC_CASEFOLD and @ref UTF8PROC_IGNORE).
 **/
UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKC_Casefold(const utf8proc_uint8_t* str);
/** @} */

#ifdef __cplusplus
}
#endif

#endif