utf8proc.c

/* -*- mode: c; c-basic-offset: 2; tab-width: 2; indent-tabs-mode: nil -*- */
/*
 *  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.
 */

/*
 *  This library contains derived data from a modified version of the
 *  Unicode data files.
 *
 *  The original data files are available at
 *  https://www.unicode.org/Public/UNIDATA/
 *
 *  Please notice the copyright statement in the file "utf8proc_data.c".
 */

/*
 *  File name:    utf8proc.c
 *
 *  Description:
 *  Implementation of libutf8proc.
 */

#include "utf8proc.h"

#ifndef SSIZE_MAX
#define SSIZE_MAX ((size_t)SIZE_MAX / 2)
#endif
#ifndef UINT16_MAX
#define UINT16_MAX 65535U
#endif

#include "utf8proc_data.c"

UTF8PROC_DLLEXPORT const utf8proc_int8_t utf8proc_utf8class[256] = {
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
    3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0};

#define UTF8PROC_HANGUL_SBASE 0xAC00
#define UTF8PROC_HANGUL_LBASE 0x1100
#define UTF8PROC_HANGUL_VBASE 0x1161
#define UTF8PROC_HANGUL_TBASE 0x11A7
#define UTF8PROC_HANGUL_LCOUNT 19
#define UTF8PROC_HANGUL_VCOUNT 21
#define UTF8PROC_HANGUL_TCOUNT 28
#define UTF8PROC_HANGUL_NCOUNT 588
#define UTF8PROC_HANGUL_SCOUNT 11172
/* END is exclusive */
#define UTF8PROC_HANGUL_L_START 0x1100
#define UTF8PROC_HANGUL_L_END 0x115A
#define UTF8PROC_HANGUL_L_FILLER 0x115F
#define UTF8PROC_HANGUL_V_START 0x1160
#define UTF8PROC_HANGUL_V_END 0x11A3
#define UTF8PROC_HANGUL_T_START 0x11A8
#define UTF8PROC_HANGUL_T_END 0x11FA
#define UTF8PROC_HANGUL_S_START 0xAC00
#define UTF8PROC_HANGUL_S_END 0xD7A4

/* Should follow semantic-versioning rules (semver.org) based on API
   compatibility.  (Note that the shared-library version number will
   be different, being based on ABI compatibility.): */
#define STRINGIZEx(x) #x
#define STRINGIZE(x) STRINGIZEx(x)
UTF8PROC_DLLEXPORT const char* utf8proc_version(void)
{
    return STRINGIZE(UTF8PROC_VERSION_MAJOR) "." STRINGIZE(UTF8PROC_VERSION_MINOR) "." STRINGIZE(UTF8PROC_VERSION_PATCH) "";
}

UTF8PROC_DLLEXPORT const char* utf8proc_unicode_version(void) { return "15.0.0"; }

UTF8PROC_DLLEXPORT const char* utf8proc_errmsg(utf8proc_ssize_t errcode)
{
    switch(errcode)
    {
    case UTF8PROC_ERROR_NOMEM: return "Memory for processing UTF-8 data could not be allocated.";
    case UTF8PROC_ERROR_OVERFLOW: return "UTF-8 string is too long to be processed.";
    case UTF8PROC_ERROR_INVALIDUTF8: return "Invalid UTF-8 string";
    case UTF8PROC_ERROR_NOTASSIGNED: return "Unassigned Unicode code point found in UTF-8 string.";
    case UTF8PROC_ERROR_INVALIDOPTS: return "Invalid options for UTF-8 processing chosen.";
    default: return "An unknown error occurred while processing UTF-8 data.";
    }
}

#define utf_cont(ch) (((ch) & 0xc0) == 0x80)
UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_iterate(const utf8proc_uint8_t* str,
                                                     utf8proc_ssize_t strlen,
                                                     utf8proc_int32_t* dst)
{
    utf8proc_int32_t uc;
    const utf8proc_uint8_t* end;

    *dst = -1;
    if(!strlen)
        return 0;
    end = str + ((strlen < 0) ? 4 : strlen);
    uc  = *str++;
    if(uc < 0x80)
    {
        *dst = uc;
        return 1;
    }
    // Must be between 0xc2 and 0xf4 inclusive to be valid
    if((utf8proc_uint32_t)(uc - 0xc2) > (0xf4 - 0xc2))
        return UTF8PROC_ERROR_INVALIDUTF8;
    if(uc < 0xe0)
    { // 2-byte sequence
        // Must have valid continuation character
        if(str >= end || !utf_cont(*str))
            return UTF8PROC_ERROR_INVALIDUTF8;
        *dst = ((uc & 0x1f) << 6) | (*str & 0x3f);
        return 2;
    }
    if(uc < 0xf0)
    { // 3-byte sequence
        if((str + 1 >= end) || !utf_cont(*str) || !utf_cont(str[1]))
            return UTF8PROC_ERROR_INVALIDUTF8;
        // Check for surrogate chars
        if(uc == 0xed && *str > 0x9f)
            return UTF8PROC_ERROR_INVALIDUTF8;
        uc = ((uc & 0xf) << 12) | ((*str & 0x3f) << 6) | (str[1] & 0x3f);
        if(uc < 0x800)
            return UTF8PROC_ERROR_INVALIDUTF8;
        *dst = uc;
        return 3;
    }
    // 4-byte sequence
    // Must have 3 valid continuation characters
    if((str + 2 >= end) || !utf_cont(*str) || !utf_cont(str[1]) || !utf_cont(str[2]))
        return UTF8PROC_ERROR_INVALIDUTF8;
    // Make sure in correct range (0x10000 - 0x10ffff)
    if(uc == 0xf0)
    {
        if(*str < 0x90)
            return UTF8PROC_ERROR_INVALIDUTF8;
    }
    else if(uc == 0xf4)
    {
        if(*str > 0x8f)
            return UTF8PROC_ERROR_INVALIDUTF8;
    }
    *dst = ((uc & 7) << 18) | ((*str & 0x3f) << 12) | ((str[1] & 0x3f) << 6) | (str[2] & 0x3f);
    return 4;
}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_codepoint_valid(utf8proc_int32_t uc)
{
    return (((utf8proc_uint32_t)uc) - 0xd800 > 0x07ff) && ((utf8proc_uint32_t)uc < 0x110000);
}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_encode_char(utf8proc_int32_t uc, utf8proc_uint8_t* dst)
{
    if(uc < 0x00)
    {
        return 0;
    }
    else if(uc < 0x80)
    {
        dst[0] = (utf8proc_uint8_t)uc;
        return 1;
    }
    else if(uc < 0x800)
    {
        dst[0] = (utf8proc_uint8_t)(0xC0 + (uc >> 6));
        dst[1] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 2;
        // Note: we allow encoding 0xd800-0xdfff here, so as not to change
        // the API, however, these are actually invalid in UTF-8
    }
    else if(uc < 0x10000)
    {
        dst[0] = (utf8proc_uint8_t)(0xE0 + (uc >> 12));
        dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));
        dst[2] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 3;
    }
    else if(uc < 0x110000)
    {
        dst[0] = (utf8proc_uint8_t)(0xF0 + (uc >> 18));
        dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 12) & 0x3F));
        dst[2] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));
        dst[3] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 4;
    }
    else
        return 0;
}

/* internal version used for inserting 0xff bytes between graphemes */
static utf8proc_ssize_t charbound_encode_char(utf8proc_int32_t uc, utf8proc_uint8_t* dst)
{
    if(uc < 0x00)
    {
        if(uc == -1)
        { /* internal value used for grapheme breaks */
            dst[0] = (utf8proc_uint8_t)0xFF;
            return 1;
        }
        return 0;
    }
    else if(uc < 0x80)
    {
        dst[0] = (utf8proc_uint8_t)uc;
        return 1;
    }
    else if(uc < 0x800)
    {
        dst[0] = (utf8proc_uint8_t)(0xC0 + (uc >> 6));
        dst[1] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 2;
    }
    else if(uc < 0x10000)
    {
        dst[0] = (utf8proc_uint8_t)(0xE0 + (uc >> 12));
        dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));
        dst[2] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 3;
    }
    else if(uc < 0x110000)
    {
        dst[0] = (utf8proc_uint8_t)(0xF0 + (uc >> 18));
        dst[1] = (utf8proc_uint8_t)(0x80 + ((uc >> 12) & 0x3F));
        dst[2] = (utf8proc_uint8_t)(0x80 + ((uc >> 6) & 0x3F));
        dst[3] = (utf8proc_uint8_t)(0x80 + (uc & 0x3F));
        return 4;
    }
    else
        return 0;
}

/* internal "unsafe" version that does not check whether uc is in range */
static const utf8proc_property_t* unsafe_get_property(utf8proc_int32_t uc)
{
    /* ASSERT: uc >= 0 && uc < 0x110000 */
    return utf8proc_properties +
           (utf8proc_stage2table[utf8proc_stage1table[uc >> 8] + (uc & 0xFF)]);
}

UTF8PROC_DLLEXPORT const utf8proc_property_t* utf8proc_get_property(utf8proc_int32_t uc)
{
    return uc < 0 || uc >= 0x110000 ? utf8proc_properties : unsafe_get_property(uc);
}

/* return whether there is a grapheme break between boundclasses lbc and tbc
   (according to the definition of extended grapheme clusters)

  Rule numbering refers to TR29 Version 29 (Unicode 9.0.0):
  http://www.unicode.org/reports/tr29/tr29-29.html

  CAVEATS:
   Please note that evaluation of GB10 (grapheme breaks between emoji zwj
  sequences) and GB 12/13 (regional indicator code points) require knowledge of
  previous characters and are thus not handled by this function. This may result
  in an incorrect break before an E_Modifier class codepoint and an incorrectly
  missing break between two REGIONAL_INDICATOR class code points if such support
  does not exist in the caller.

   See the special support in grapheme_break_extended, for required bookkeeping
  by the caller.
*/
static utf8proc_bool grapheme_break_simple(int lbc, int tbc)
{
    return (lbc == UTF8PROC_BOUNDCLASS_START) ? true : // GB1
               (lbc == UTF8PROC_BOUNDCLASS_CR &&       // GB3
                tbc == UTF8PROC_BOUNDCLASS_LF)
               ? false
               : // ---
               (lbc >= UTF8PROC_BOUNDCLASS_CR && lbc <= UTF8PROC_BOUNDCLASS_CONTROL) ? true
                                                                                     : // GB4
               (tbc >= UTF8PROC_BOUNDCLASS_CR && tbc <= UTF8PROC_BOUNDCLASS_CONTROL) ? true
                                                                                     : // GB5
               (lbc == UTF8PROC_BOUNDCLASS_L &&                                        // GB6
                (tbc == UTF8PROC_BOUNDCLASS_L ||                                       // ---
                 tbc == UTF8PROC_BOUNDCLASS_V ||                                       // ---
                 tbc == UTF8PROC_BOUNDCLASS_LV ||                                      // ---
                 tbc == UTF8PROC_BOUNDCLASS_LVT))
               ? false
               :                                  // ---
               ((lbc == UTF8PROC_BOUNDCLASS_LV || // GB7
                 lbc == UTF8PROC_BOUNDCLASS_V) && // ---
                (tbc == UTF8PROC_BOUNDCLASS_V ||  // ---
                 tbc == UTF8PROC_BOUNDCLASS_T))
               ? false
               :                                   // ---
               ((lbc == UTF8PROC_BOUNDCLASS_LVT || // GB8
                 lbc == UTF8PROC_BOUNDCLASS_T) &&  // ---
                tbc == UTF8PROC_BOUNDCLASS_T)
               ? false
               :                                          // ---
               (tbc == UTF8PROC_BOUNDCLASS_EXTEND ||      // GB9
                tbc == UTF8PROC_BOUNDCLASS_ZWJ ||         // ---
                tbc == UTF8PROC_BOUNDCLASS_SPACINGMARK || // GB9a
                lbc == UTF8PROC_BOUNDCLASS_PREPEND)
               ? false
               :                                    // GB9b
               (lbc == UTF8PROC_BOUNDCLASS_E_ZWG && // GB11 (requires additional
                                                    // handling below)
                tbc == UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC)
               ? false
               :                                                 // ----
               (lbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR && // GB12/13
                                                                 // (requires
                                                                 // additional
                                                                 // handling below)
                tbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR)
               ? false
               :     // ----
               true; // GB999
}

static utf8proc_bool grapheme_break_extended(int lbc, int tbc, utf8proc_int32_t* state)
{
    if(state)
    {
        int lbc_override;
        if(*state == UTF8PROC_BOUNDCLASS_START)
            *state = lbc_override = lbc;
        else
            lbc_override = *state;
        utf8proc_bool break_permitted = grapheme_break_simple(lbc_override, tbc);

        // Special support for GB 12/13 made possible by GB999. After two RI
        // class codepoints we want to force a break. Do this by resetting the
        // second RI's bound class to UTF8PROC_BOUNDCLASS_OTHER, to force a break
        // after that character according to GB999 (unless of course such a break is
        // forbidden by a different rule such as GB9).
        if(*state == tbc && tbc == UTF8PROC_BOUNDCLASS_REGIONAL_INDICATOR)
            *state = UTF8PROC_BOUNDCLASS_OTHER;
        // Special support for GB11 (emoji extend* zwj / emoji)
        else if(*state == UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC)
        {
            if(tbc == UTF8PROC_BOUNDCLASS_EXTEND) // fold EXTEND codepoints into emoji
                *state = UTF8PROC_BOUNDCLASS_EXTENDED_PICTOGRAPHIC;
            else if(tbc == UTF8PROC_BOUNDCLASS_ZWJ)
                *state = UTF8PROC_BOUNDCLASS_E_ZWG; // state to record emoji+zwg combo
            else
                *state = tbc;
        }
        else
            *state = tbc;

        return break_permitted;
    }
    else
        return grapheme_break_simple(lbc, tbc);
}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break_stateful(utf8proc_int32_t c1,
                                                                  utf8proc_int32_t c2,
                                                                  utf8proc_int32_t* state)
{
    return grapheme_break_extended(
        utf8proc_get_property(c1)->boundclass, utf8proc_get_property(c2)->boundclass, state);
}

UTF8PROC_DLLEXPORT utf8proc_bool utf8proc_grapheme_break(utf8proc_int32_t c1, utf8proc_int32_t c2)
{
    return utf8proc_grapheme_break_stateful(c1, c2, NULL);
}

static utf8proc_int32_t seqindex_decode_entry(const utf8proc_uint16_t** entry)
{
    utf8proc_int32_t entry_cp = **entry;
    if((entry_cp & 0xF800) == 0xD800)
    {
        *entry   = *entry + 1;
        entry_cp = ((entry_cp & 0x03FF) << 10) | (**entry & 0x03FF);
        entry_cp += 0x10000;
    }
    return entry_cp;
}

static utf8proc_int32_t seqindex_decode_index(const utf8proc_uint32_t seqindex)
{
    const utf8proc_uint16_t* entry = &utf8proc_sequences[seqindex];
    return seqindex_decode_entry(&entry);
}

static utf8proc_ssize_t seqindex_write_char_decomposed(utf8proc_uint16_t seqindex,
                                                       utf8proc_int32_t* dst,
                                                       utf8proc_ssize_t bufsize,
                                                       utf8proc_option_t options,
                                                       int* last_boundclass)
{
    utf8proc_ssize_t written       = 0;
    const utf8proc_uint16_t* entry = &utf8proc_sequences[seqindex & 0x3FFF];
    int len                        = seqindex >> 14;
    if(len >= 3)
    {
        len = *entry;
        entry++;
    }
    for(; len >= 0; entry++, len--)
    {
        utf8proc_int32_t entry_cp = seqindex_decode_entry(&entry);

        written += utf8proc_decompose_char(entry_cp,
                                           dst + written,
                                           (bufsize > written) ? (bufsize - written) : 0,
                                           options,
                                           last_boundclass);
        if(written < 0)
            return UTF8PROC_ERROR_OVERFLOW;
    }
    return written;
}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_tolower(utf8proc_int32_t c)
{
    utf8proc_int32_t cl = utf8proc_get_property(c)->lowercase_seqindex;
    return cl != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cl) : c;
}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_toupper(utf8proc_int32_t c)
{
    utf8proc_int32_t cu = utf8proc_get_property(c)->uppercase_seqindex;
    return cu != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cu) : c;
}

UTF8PROC_DLLEXPORT utf8proc_int32_t utf8proc_totitle(utf8proc_int32_t c)
{
    utf8proc_int32_t cu = utf8proc_get_property(c)->titlecase_seqindex;
    return cu != UINT16_MAX ? seqindex_decode_index((utf8proc_uint32_t)cu) : c;
}

UTF8PROC_DLLEXPORT int utf8proc_islower(utf8proc_int32_t c)
{
    const utf8proc_property_t* p = utf8proc_get_property(c);
    return p->lowercase_seqindex != p->uppercase_seqindex && p->lowercase_seqindex == UINT16_MAX;
}

UTF8PROC_DLLEXPORT int utf8proc_isupper(utf8proc_int32_t c)
{
    const utf8proc_property_t* p = utf8proc_get_property(c);
    return p->lowercase_seqindex != p->uppercase_seqindex && p->uppercase_seqindex == UINT16_MAX &&
           p->category != UTF8PROC_CATEGORY_LT;
}

/* return a character width analogous to wcwidth (except portable and
   hopefully less buggy than most system wcwidth functions). */
UTF8PROC_DLLEXPORT int utf8proc_charwidth(utf8proc_int32_t c)
{
    return utf8proc_get_property(c)->charwidth;
}

UTF8PROC_DLLEXPORT utf8proc_category_t utf8proc_category(utf8proc_int32_t c)
{
    return (utf8proc_category_t)utf8proc_get_property(c)->category;
}

UTF8PROC_DLLEXPORT const char* utf8proc_category_string(utf8proc_int32_t c)
{
    static const char s[][3] = {"Cn", "Lu", "Ll", "Lt", "Lm", "Lo", "Mn", "Mc", "Me", "Nd",
                                "Nl", "No", "Pc", "Pd", "Ps", "Pe", "Pi", "Pf", "Po", "Sm",
                                "Sc", "Sk", "So", "Zs", "Zl", "Zp", "Cc", "Cf", "Cs", "Co"};
    return s[utf8proc_category(c)];
}

#define utf8proc_decompose_lump(replacement_uc) \
    return utf8proc_decompose_char(             \
        (replacement_uc), dst, bufsize, options & ~(unsigned int)UTF8PROC_LUMP, last_boundclass)

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_decompose_char(utf8proc_int32_t uc,
                                                            utf8proc_int32_t* dst,
                                                            utf8proc_ssize_t bufsize,
                                                            utf8proc_option_t options,
                                                            int* last_boundclass)
{
    const utf8proc_property_t* property;
    utf8proc_propval_t category;
    utf8proc_int32_t hangul_sindex;
    if(uc < 0 || uc >= 0x110000)
        return UTF8PROC_ERROR_NOTASSIGNED;
    property      = unsafe_get_property(uc);
    category      = property->category;
    hangul_sindex = uc - UTF8PROC_HANGUL_SBASE;
    if(options & (UTF8PROC_COMPOSE | UTF8PROC_DECOMPOSE))
    {
        if(hangul_sindex >= 0 && hangul_sindex < UTF8PROC_HANGUL_SCOUNT)
        {
            utf8proc_int32_t hangul_tindex;
            if(bufsize >= 1)
            {
                dst[0] = UTF8PROC_HANGUL_LBASE + hangul_sindex / UTF8PROC_HANGUL_NCOUNT;
                if(bufsize >= 2)
                    dst[1] = UTF8PROC_HANGUL_VBASE +
                             (hangul_sindex % UTF8PROC_HANGUL_NCOUNT) / UTF8PROC_HANGUL_TCOUNT;
            }
            hangul_tindex = hangul_sindex % UTF8PROC_HANGUL_TCOUNT;
            if(!hangul_tindex)
                return 2;
            if(bufsize >= 3)
                dst[2] = UTF8PROC_HANGUL_TBASE + hangul_tindex;
            return 3;
        }
    }
    if(options & UTF8PROC_REJECTNA)
    {
        if(!category)
            return UTF8PROC_ERROR_NOTASSIGNED;
    }
    if(options & UTF8PROC_IGNORE)
    {
        if(property->ignorable)
            return 0;
    }
    if(options & UTF8PROC_STRIPNA)
    {
        if(!category)
            return 0;
    }
    if(options & UTF8PROC_LUMP)
    {
        if(category == UTF8PROC_CATEGORY_ZS)
            utf8proc_decompose_lump(0x0020);
        if(uc == 0x2018 || uc == 0x2019 || uc == 0x02BC || uc == 0x02C8)
            utf8proc_decompose_lump(0x0027);
        if(category == UTF8PROC_CATEGORY_PD || uc == 0x2212)
            utf8proc_decompose_lump(0x002D);
        if(uc == 0x2044 || uc == 0x2215)
            utf8proc_decompose_lump(0x002F);
        if(uc == 0x2236)
            utf8proc_decompose_lump(0x003A);
        if(uc == 0x2039 || uc == 0x2329 || uc == 0x3008)
            utf8proc_decompose_lump(0x003C);
        if(uc == 0x203A || uc == 0x232A || uc == 0x3009)
            utf8proc_decompose_lump(0x003E);
        if(uc == 0x2216)
            utf8proc_decompose_lump(0x005C);
        if(uc == 0x02C4 || uc == 0x02C6 || uc == 0x2038 || uc == 0x2303)
            utf8proc_decompose_lump(0x005E);
        if(category == UTF8PROC_CATEGORY_PC || uc == 0x02CD)
            utf8proc_decompose_lump(0x005F);
        if(uc == 0x02CB)
            utf8proc_decompose_lump(0x0060);
        if(uc == 0x2223)
            utf8proc_decompose_lump(0x007C);
        if(uc == 0x223C)
            utf8proc_decompose_lump(0x007E);
        if((options & UTF8PROC_NLF2LS) && (options & UTF8PROC_NLF2PS))
        {
            if(category == UTF8PROC_CATEGORY_ZL || category == UTF8PROC_CATEGORY_ZP)
                utf8proc_decompose_lump(0x000A);
        }
    }
    if(options & UTF8PROC_STRIPMARK)
    {
        if(category == UTF8PROC_CATEGORY_MN || category == UTF8PROC_CATEGORY_MC ||
           category == UTF8PROC_CATEGORY_ME)
            return 0;
    }
    if(options & UTF8PROC_CASEFOLD)
    {
        if(property->casefold_seqindex != UINT16_MAX)
        {
            return seqindex_write_char_decomposed(
                property->casefold_seqindex, dst, bufsize, options, last_boundclass);
        }
    }
    if(options & (UTF8PROC_COMPOSE | UTF8PROC_DECOMPOSE))
    {
        if(property->decomp_seqindex != UINT16_MAX &&
           (!property->decomp_type || (options & UTF8PROC_COMPAT)))
        {
            return seqindex_write_char_decomposed(
                property->decomp_seqindex, dst, bufsize, options, last_boundclass);
        }
    }
    if(options & UTF8PROC_CHARBOUND)
    {
        utf8proc_bool boundary;
        int tbc  = property->boundclass;
        boundary = grapheme_break_extended(*last_boundclass, tbc, last_boundclass);
        if(boundary)
        {
            if(bufsize >= 1)
                dst[0] = -1; /* sentinel value for grapheme break */
            if(bufsize >= 2)
                dst[1] = uc;
            return 2;
        }
    }
    if(bufsize >= 1)
        *dst = uc;
    return 1;
}

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)
{
    return utf8proc_decompose_custom(str, strlen, buffer, bufsize, options, NULL, NULL);
}

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)
{
    /* strlen will be ignored, if UTF8PROC_NULLTERM is set in options */
    utf8proc_ssize_t wpos = 0;
    if((options & UTF8PROC_COMPOSE) && (options & UTF8PROC_DECOMPOSE))
        return UTF8PROC_ERROR_INVALIDOPTS;
    if((options & UTF8PROC_STRIPMARK) && !(options & UTF8PROC_COMPOSE) &&
       !(options & UTF8PROC_DECOMPOSE))
        return UTF8PROC_ERROR_INVALIDOPTS;
    {
        utf8proc_int32_t uc;
        utf8proc_ssize_t rpos = 0;
        utf8proc_ssize_t decomp_result;
        int boundclass = UTF8PROC_BOUNDCLASS_START;
        while(1)
        {
            if(options & UTF8PROC_NULLTERM)
            {
                rpos += utf8proc_iterate(str + rpos, -1, &uc);
                /* checking of return value is not necessary,
                   as 'uc' is < 0 in case of error */
                if(uc < 0)
                    return UTF8PROC_ERROR_INVALIDUTF8;
                if(rpos < 0)
                    return UTF8PROC_ERROR_OVERFLOW;
                if(uc == 0)
                    break;
            }
            else
            {
                if(rpos >= strlen)
                    break;
                rpos += utf8proc_iterate(str + rpos, strlen - rpos, &uc);
                if(uc < 0)
                    return UTF8PROC_ERROR_INVALIDUTF8;
            }
            if(custom_func != NULL)
            {
                uc = custom_func(uc, custom_data); /* user-specified custom mapping */
            }
            decomp_result = utf8proc_decompose_char(
                uc, buffer + wpos, (bufsize > wpos) ? (bufsize - wpos) : 0, options, &boundclass);
            if(decomp_result < 0)
                return decomp_result;
            wpos += decomp_result;
            /* prohibiting integer overflows due to too long strings: */
            if(wpos < 0 || wpos > (utf8proc_ssize_t)(SSIZE_MAX / sizeof(utf8proc_int32_t) / 2))
                return UTF8PROC_ERROR_OVERFLOW;
        }
    }
    if((options & (UTF8PROC_COMPOSE | UTF8PROC_DECOMPOSE)) && bufsize >= wpos)
    {
        utf8proc_ssize_t pos = 0;
        while(pos < wpos - 1)
        {
            utf8proc_int32_t uc1, uc2;
            const utf8proc_property_t *property1, *property2;
            uc1       = buffer[pos];
            uc2       = buffer[pos + 1];
            property1 = unsafe_get_property(uc1);
            property2 = unsafe_get_property(uc2);
            if(property1->combining_class > property2->combining_class &&
               property2->combining_class > 0)
            {
                buffer[pos]     = uc2;
                buffer[pos + 1] = uc1;
                if(pos > 0)
                    pos--;
                else
                    pos++;
            }
            else
            {
                pos++;
            }
        }
    }
    return wpos;
}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_normalize_utf32(utf8proc_int32_t* buffer,
                                                             utf8proc_ssize_t length,
                                                             utf8proc_option_t options)
{
    /* UTF8PROC_NULLTERM option will be ignored, 'length' is never ignored */
    if(options & (UTF8PROC_NLF2LS | UTF8PROC_NLF2PS | UTF8PROC_STRIPCC))
    {
        utf8proc_ssize_t rpos;
        utf8proc_ssize_t wpos = 0;
        utf8proc_int32_t uc;
        for(rpos = 0; rpos < length; rpos++)
        {
            uc = buffer[rpos];
            if(uc == 0x000D && rpos < length - 1 && buffer[rpos + 1] == 0x000A)
                rpos++;
            if(uc == 0x000A || uc == 0x000D || uc == 0x0085 ||
               ((options & UTF8PROC_STRIPCC) && (uc == 0x000B || uc == 0x000C)))
            {
                if(options & UTF8PROC_NLF2LS)
                {
                    if(options & UTF8PROC_NLF2PS)
                    {
                        buffer[wpos++] = 0x000A;
                    }
                    else
                    {
                        buffer[wpos++] = 0x2028;
                    }
                }
                else
                {
                    if(options & UTF8PROC_NLF2PS)
                    {
                        buffer[wpos++] = 0x2029;
                    }
                    else
                    {
                        buffer[wpos++] = 0x0020;
                    }
                }
            }
            else if((options & UTF8PROC_STRIPCC) && (uc < 0x0020 || (uc >= 0x007F && uc < 0x00A0)))
            {
                if(uc == 0x0009)
                    buffer[wpos++] = 0x0020;
            }
            else
            {
                buffer[wpos++] = uc;
            }
        }
        length = wpos;
    }
    if(options & UTF8PROC_COMPOSE)
    {
        utf8proc_int32_t* starter = NULL;
        utf8proc_int32_t current_char;
        const utf8proc_property_t *starter_property = NULL, *current_property;
        utf8proc_propval_t max_combining_class      = -1;
        utf8proc_ssize_t rpos;
        utf8proc_ssize_t wpos = 0;
        utf8proc_int32_t composition;
        for(rpos = 0; rpos < length; rpos++)
        {
            current_char     = buffer[rpos];
            current_property = unsafe_get_property(current_char);
            if(starter && current_property->combining_class > max_combining_class)
            {
                /* combination perhaps possible */
                utf8proc_int32_t hangul_lindex;
                utf8proc_int32_t hangul_sindex;
                hangul_lindex = *starter - UTF8PROC_HANGUL_LBASE;
                if(hangul_lindex >= 0 && hangul_lindex < UTF8PROC_HANGUL_LCOUNT)
                {
                    utf8proc_int32_t hangul_vindex;
                    hangul_vindex = current_char - UTF8PROC_HANGUL_VBASE;
                    if(hangul_vindex >= 0 && hangul_vindex < UTF8PROC_HANGUL_VCOUNT)
                    {
                        *starter = UTF8PROC_HANGUL_SBASE +
                                   (hangul_lindex * UTF8PROC_HANGUL_VCOUNT + hangul_vindex) *
                                       UTF8PROC_HANGUL_TCOUNT;
                        starter_property = NULL;
                        continue;
                    }
                }
                hangul_sindex = *starter - UTF8PROC_HANGUL_SBASE;
                if(hangul_sindex >= 0 && hangul_sindex < UTF8PROC_HANGUL_SCOUNT &&
                   (hangul_sindex % UTF8PROC_HANGUL_TCOUNT) == 0)
                {
                    utf8proc_int32_t hangul_tindex;
                    hangul_tindex = current_char - UTF8PROC_HANGUL_TBASE;
                    if(hangul_tindex >= 0 && hangul_tindex < UTF8PROC_HANGUL_TCOUNT)
                    {
                        *starter += hangul_tindex;
                        starter_property = NULL;
                        continue;
                    }
                }
                if(!starter_property)
                {
                    starter_property = unsafe_get_property(*starter);
                }
                if(starter_property->comb_index < 0x8000 &&
                   current_property->comb_index != UINT16_MAX &&
                   current_property->comb_index >= 0x8000)
                {
                    int sidx = starter_property->comb_index;
                    int idx  = current_property->comb_index & 0x3FFF;
                    if(idx >= utf8proc_combinations[sidx] && idx <= utf8proc_combinations[sidx + 1])
                    {
                        idx += sidx + 2 - utf8proc_combinations[sidx];
                        if(current_property->comb_index & 0x4000)
                        {
                            composition =
                                (utf8proc_combinations[idx] << 16) | utf8proc_combinations[idx + 1];
                        }
                        else
                            composition = utf8proc_combinations[idx];

                        if(composition > 0 && (!(options & UTF8PROC_STABLE) ||
                                               !(unsafe_get_property(composition)->comp_exclusion)))
                        {
                            *starter         = composition;
                            starter_property = NULL;
                            continue;
                        }
                    }
                }
            }
            buffer[wpos] = current_char;
            if(current_property->combining_class)
            {
                if(current_property->combining_class > max_combining_class)
                {
                    max_combining_class = current_property->combining_class;
                }
            }
            else
            {
                starter             = buffer + wpos;
                starter_property    = NULL;
                max_combining_class = -1;
            }
            wpos++;
        }
        length = wpos;
    }
    return length;
}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_reencode(utf8proc_int32_t* buffer,
                                                      utf8proc_ssize_t length,
                                                      utf8proc_option_t options)
{
    /* UTF8PROC_NULLTERM option will be ignored, 'length' is never ignored
       ASSERT: 'buffer' has one spare byte of free space at the end! */
    length = utf8proc_normalize_utf32(buffer, length, options);
    if(length < 0)
        return length;
    {
        utf8proc_ssize_t rpos, wpos = 0;
        utf8proc_int32_t uc;
        if(options & UTF8PROC_CHARBOUND)
        {
            for(rpos = 0; rpos < length; rpos++)
            {
                uc = buffer[rpos];
                wpos += charbound_encode_char(uc, ((utf8proc_uint8_t*)buffer) + wpos);
            }
        }
        else
        {
            for(rpos = 0; rpos < length; rpos++)
            {
                uc = buffer[rpos];
                wpos += utf8proc_encode_char(uc, ((utf8proc_uint8_t*)buffer) + wpos);
            }
        }
        ((utf8proc_uint8_t*)buffer)[wpos] = 0;
        return wpos;
    }
}

UTF8PROC_DLLEXPORT utf8proc_ssize_t utf8proc_map(const utf8proc_uint8_t* str,
                                                 utf8proc_ssize_t strlen,
                                                 utf8proc_uint8_t** dstptr,
                                                 utf8proc_option_t options)
{
    return utf8proc_map_custom(str, strlen, dstptr, options, NULL, 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)
{
    utf8proc_int32_t* buffer;
    utf8proc_ssize_t result;
    *dstptr = NULL;
    result  = utf8proc_decompose_custom(str, strlen, NULL, 0, options, custom_func, custom_data);
    if(result < 0)
        return result;
    buffer = (utf8proc_int32_t*)malloc(((utf8proc_size_t)result) * sizeof(utf8proc_int32_t) + 1);
    if(!buffer)
        return UTF8PROC_ERROR_NOMEM;
    result =
        utf8proc_decompose_custom(str, strlen, buffer, result, options, custom_func, custom_data);
    if(result < 0)
    {
        free(buffer);
        return result;
    }
    result = utf8proc_reencode(buffer, result, options);
    if(result < 0)
    {
        free(buffer);
        return result;
    }
    {
        utf8proc_int32_t* newptr;
        newptr = (utf8proc_int32_t*)realloc(buffer, (size_t)result + 1);
        if(newptr)
            buffer = newptr;
    }
    *dstptr = (utf8proc_uint8_t*)buffer;
    return result;
}

UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFD(const utf8proc_uint8_t* str)
{
    utf8proc_uint8_t* retval;
    utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_DECOMPOSE);
    return retval;
}

UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFC(const utf8proc_uint8_t* str)
{
    utf8proc_uint8_t* retval;
    utf8proc_map(str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_COMPOSE);
    return retval;
}

UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKD(const utf8proc_uint8_t* str)
{
    utf8proc_uint8_t* retval;
    utf8proc_map(str,
                 0,
                 &retval,
                 UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_DECOMPOSE | UTF8PROC_COMPAT);
    return retval;
}

UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKC(const utf8proc_uint8_t* str)
{
    utf8proc_uint8_t* retval;
    utf8proc_map(
        str, 0, &retval, UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_COMPOSE | UTF8PROC_COMPAT);
    return retval;
}

UTF8PROC_DLLEXPORT utf8proc_uint8_t* utf8proc_NFKC_Casefold(const utf8proc_uint8_t* str)
{
    utf8proc_uint8_t* retval;
    utf8proc_map(str,
                 0,
                 &retval,
                 UTF8PROC_NULLTERM | UTF8PROC_STABLE | UTF8PROC_COMPOSE | UTF8PROC_COMPAT |
                     UTF8PROC_CASEFOLD | UTF8PROC_IGNORE);
    return retval;
}