// Copyright 2022 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
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// 3. Neither the name of the copyright holder nor the names of its
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//    this software without specific prior written permission.
//
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// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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#include "src/tint/utils/text/unicode.h"

#include <algorithm>

namespace tint {
namespace {

struct CodePointRange {
    uint32_t first;  // First code point in the interval
    uint32_t last;   // Last code point in the interval (inclusive)
};

inline bool operator<(CodePoint code_point, CodePointRange range) {
    return code_point < range.first;
}
inline bool operator<(CodePointRange range, CodePoint code_point) {
    return range.last < code_point;
}

// Interval ranges of all code points in the Unicode 14 XID_Start set
// This array needs to be in ascending order.
constexpr CodePointRange kXIDStartRanges[] = {
    {0x00041, 0x0005a}, {0x00061, 0x0007a}, {0x000aa, 0x000aa}, {0x000b5, 0x000b5},
    {0x000ba, 0x000ba}, {0x000c0, 0x000d6}, {0x000d8, 0x000f6}, {0x000f8, 0x002c1},
    {0x002c6, 0x002d1}, {0x002e0, 0x002e4}, {0x002ec, 0x002ec}, {0x002ee, 0x002ee},
    {0x00370, 0x00374}, {0x00376, 0x00377}, {0x0037b, 0x0037d}, {0x0037f, 0x0037f},
    {0x00386, 0x00386}, {0x00388, 0x0038a}, {0x0038c, 0x0038c}, {0x0038e, 0x003a1},
    {0x003a3, 0x003f5}, {0x003f7, 0x00481}, {0x0048a, 0x0052f}, {0x00531, 0x00556},
    {0x00559, 0x00559}, {0x00560, 0x00588}, {0x005d0, 0x005ea}, {0x005ef, 0x005f2},
    {0x00620, 0x0064a}, {0x0066e, 0x0066f}, {0x00671, 0x006d3}, {0x006d5, 0x006d5},
    {0x006e5, 0x006e6}, {0x006ee, 0x006ef}, {0x006fa, 0x006fc}, {0x006ff, 0x006ff},
    {0x00710, 0x00710}, {0x00712, 0x0072f}, {0x0074d, 0x007a5}, {0x007b1, 0x007b1},
    {0x007ca, 0x007ea}, {0x007f4, 0x007f5}, {0x007fa, 0x007fa}, {0x00800, 0x00815},
    {0x0081a, 0x0081a}, {0x00824, 0x00824}, {0x00828, 0x00828}, {0x00840, 0x00858},
    {0x00860, 0x0086a}, {0x00870, 0x00887}, {0x00889, 0x0088e}, {0x008a0, 0x008c9},
    {0x00904, 0x00939}, {0x0093d, 0x0093d}, {0x00950, 0x00950}, {0x00958, 0x00961},
    {0x00971, 0x00980}, {0x00985, 0x0098c}, {0x0098f, 0x00990}, {0x00993, 0x009a8},
    {0x009aa, 0x009b0}, {0x009b2, 0x009b2}, {0x009b6, 0x009b9}, {0x009bd, 0x009bd},
    {0x009ce, 0x009ce}, {0x009dc, 0x009dd}, {0x009df, 0x009e1}, {0x009f0, 0x009f1},
    {0x009fc, 0x009fc}, {0x00a05, 0x00a0a}, {0x00a0f, 0x00a10}, {0x00a13, 0x00a28},
    {0x00a2a, 0x00a30}, {0x00a32, 0x00a33}, {0x00a35, 0x00a36}, {0x00a38, 0x00a39},
    {0x00a59, 0x00a5c}, {0x00a5e, 0x00a5e}, {0x00a72, 0x00a74}, {0x00a85, 0x00a8d},
    {0x00a8f, 0x00a91}, {0x00a93, 0x00aa8}, {0x00aaa, 0x00ab0}, {0x00ab2, 0x00ab3},
    {0x00ab5, 0x00ab9}, {0x00abd, 0x00abd}, {0x00ad0, 0x00ad0}, {0x00ae0, 0x00ae1},
    {0x00af9, 0x00af9}, {0x00b05, 0x00b0c}, {0x00b0f, 0x00b10}, {0x00b13, 0x00b28},
    {0x00b2a, 0x00b30}, {0x00b32, 0x00b33}, {0x00b35, 0x00b39}, {0x00b3d, 0x00b3d},
    {0x00b5c, 0x00b5d}, {0x00b5f, 0x00b61}, {0x00b71, 0x00b71}, {0x00b83, 0x00b83},
    {0x00b85, 0x00b8a}, {0x00b8e, 0x00b90}, {0x00b92, 0x00b95}, {0x00b99, 0x00b9a},
    {0x00b9c, 0x00b9c}, {0x00b9e, 0x00b9f}, {0x00ba3, 0x00ba4}, {0x00ba8, 0x00baa},
    {0x00bae, 0x00bb9}, {0x00bd0, 0x00bd0}, {0x00c05, 0x00c0c}, {0x00c0e, 0x00c10},
    {0x00c12, 0x00c28}, {0x00c2a, 0x00c39}, {0x00c3d, 0x00c3d}, {0x00c58, 0x00c5a},
    {0x00c5d, 0x00c5d}, {0x00c60, 0x00c61}, {0x00c80, 0x00c80}, {0x00c85, 0x00c8c},
    {0x00c8e, 0x00c90}, {0x00c92, 0x00ca8}, {0x00caa, 0x00cb3}, {0x00cb5, 0x00cb9},
    {0x00cbd, 0x00cbd}, {0x00cdd, 0x00cde}, {0x00ce0, 0x00ce1}, {0x00cf1, 0x00cf2},
    {0x00d04, 0x00d0c}, {0x00d0e, 0x00d10}, {0x00d12, 0x00d3a}, {0x00d3d, 0x00d3d},
    {0x00d4e, 0x00d4e}, {0x00d54, 0x00d56}, {0x00d5f, 0x00d61}, {0x00d7a, 0x00d7f},
    {0x00d85, 0x00d96}, {0x00d9a, 0x00db1}, {0x00db3, 0x00dbb}, {0x00dbd, 0x00dbd},
    {0x00dc0, 0x00dc6}, {0x00e01, 0x00e30}, {0x00e32, 0x00e32}, {0x00e40, 0x00e46},
    {0x00e81, 0x00e82}, {0x00e84, 0x00e84}, {0x00e86, 0x00e8a}, {0x00e8c, 0x00ea3},
    {0x00ea5, 0x00ea5}, {0x00ea7, 0x00eb0}, {0x00eb2, 0x00eb2}, {0x00ebd, 0x00ebd},
    {0x00ec0, 0x00ec4}, {0x00ec6, 0x00ec6}, {0x00edc, 0x00edf}, {0x00f00, 0x00f00},
    {0x00f40, 0x00f47}, {0x00f49, 0x00f6c}, {0x00f88, 0x00f8c}, {0x01000, 0x0102a},
    {0x0103f, 0x0103f}, {0x01050, 0x01055}, {0x0105a, 0x0105d}, {0x01061, 0x01061},
    {0x01065, 0x01066}, {0x0106e, 0x01070}, {0x01075, 0x01081}, {0x0108e, 0x0108e},
    {0x010a0, 0x010c5}, {0x010c7, 0x010c7}, {0x010cd, 0x010cd}, {0x010d0, 0x010fa},
    {0x010fc, 0x01248}, {0x0124a, 0x0124d}, {0x01250, 0x01256}, {0x01258, 0x01258},
    {0x0125a, 0x0125d}, {0x01260, 0x01288}, {0x0128a, 0x0128d}, {0x01290, 0x012b0},
    {0x012b2, 0x012b5}, {0x012b8, 0x012be}, {0x012c0, 0x012c0}, {0x012c2, 0x012c5},
    {0x012c8, 0x012d6}, {0x012d8, 0x01310}, {0x01312, 0x01315}, {0x01318, 0x0135a},
    {0x01380, 0x0138f}, {0x013a0, 0x013f5}, {0x013f8, 0x013fd}, {0x01401, 0x0166c},
    {0x0166f, 0x0167f}, {0x01681, 0x0169a}, {0x016a0, 0x016ea}, {0x016ee, 0x016f8},
    {0x01700, 0x01711}, {0x0171f, 0x01731}, {0x01740, 0x01751}, {0x01760, 0x0176c},
    {0x0176e, 0x01770}, {0x01780, 0x017b3}, {0x017d7, 0x017d7}, {0x017dc, 0x017dc},
    {0x01820, 0x01878}, {0x01880, 0x018a8}, {0x018aa, 0x018aa}, {0x018b0, 0x018f5},
    {0x01900, 0x0191e}, {0x01950, 0x0196d}, {0x01970, 0x01974}, {0x01980, 0x019ab},
    {0x019b0, 0x019c9}, {0x01a00, 0x01a16}, {0x01a20, 0x01a54}, {0x01aa7, 0x01aa7},
    {0x01b05, 0x01b33}, {0x01b45, 0x01b4c}, {0x01b83, 0x01ba0}, {0x01bae, 0x01baf},
    {0x01bba, 0x01be5}, {0x01c00, 0x01c23}, {0x01c4d, 0x01c4f}, {0x01c5a, 0x01c7d},
    {0x01c80, 0x01c88}, {0x01c90, 0x01cba}, {0x01cbd, 0x01cbf}, {0x01ce9, 0x01cec},
    {0x01cee, 0x01cf3}, {0x01cf5, 0x01cf6}, {0x01cfa, 0x01cfa}, {0x01d00, 0x01dbf},
    {0x01e00, 0x01f15}, {0x01f18, 0x01f1d}, {0x01f20, 0x01f45}, {0x01f48, 0x01f4d},
    {0x01f50, 0x01f57}, {0x01f59, 0x01f59}, {0x01f5b, 0x01f5b}, {0x01f5d, 0x01f5d},
    {0x01f5f, 0x01f7d}, {0x01f80, 0x01fb4}, {0x01fb6, 0x01fbc}, {0x01fbe, 0x01fbe},
    {0x01fc2, 0x01fc4}, {0x01fc6, 0x01fcc}, {0x01fd0, 0x01fd3}, {0x01fd6, 0x01fdb},
    {0x01fe0, 0x01fec}, {0x01ff2, 0x01ff4}, {0x01ff6, 0x01ffc}, {0x02071, 0x02071},
    {0x0207f, 0x0207f}, {0x02090, 0x0209c}, {0x02102, 0x02102}, {0x02107, 0x02107},
    {0x0210a, 0x02113}, {0x02115, 0x02115}, {0x02118, 0x0211d}, {0x02124, 0x02124},
    {0x02126, 0x02126}, {0x02128, 0x02128}, {0x0212a, 0x02139}, {0x0213c, 0x0213f},
    {0x02145, 0x02149}, {0x0214e, 0x0214e}, {0x02160, 0x02188}, {0x02c00, 0x02ce4},
    {0x02ceb, 0x02cee}, {0x02cf2, 0x02cf3}, {0x02d00, 0x02d25}, {0x02d27, 0x02d27},
    {0x02d2d, 0x02d2d}, {0x02d30, 0x02d67}, {0x02d6f, 0x02d6f}, {0x02d80, 0x02d96},
    {0x02da0, 0x02da6}, {0x02da8, 0x02dae}, {0x02db0, 0x02db6}, {0x02db8, 0x02dbe},
    {0x02dc0, 0x02dc6}, {0x02dc8, 0x02dce}, {0x02dd0, 0x02dd6}, {0x02dd8, 0x02dde},
    {0x03005, 0x03007}, {0x03021, 0x03029}, {0x03031, 0x03035}, {0x03038, 0x0303c},
    {0x03041, 0x03096}, {0x0309d, 0x0309f}, {0x030a1, 0x030fa}, {0x030fc, 0x030ff},
    {0x03105, 0x0312f}, {0x03131, 0x0318e}, {0x031a0, 0x031bf}, {0x031f0, 0x031ff},
    {0x03400, 0x04dbf}, {0x04e00, 0x0a48c}, {0x0a4d0, 0x0a4fd}, {0x0a500, 0x0a60c},
    {0x0a610, 0x0a61f}, {0x0a62a, 0x0a62b}, {0x0a640, 0x0a66e}, {0x0a67f, 0x0a69d},
    {0x0a6a0, 0x0a6ef}, {0x0a717, 0x0a71f}, {0x0a722, 0x0a788}, {0x0a78b, 0x0a7ca},
    {0x0a7d0, 0x0a7d1}, {0x0a7d3, 0x0a7d3}, {0x0a7d5, 0x0a7d9}, {0x0a7f2, 0x0a801},
    {0x0a803, 0x0a805}, {0x0a807, 0x0a80a}, {0x0a80c, 0x0a822}, {0x0a840, 0x0a873},
    {0x0a882, 0x0a8b3}, {0x0a8f2, 0x0a8f7}, {0x0a8fb, 0x0a8fb}, {0x0a8fd, 0x0a8fe},
    {0x0a90a, 0x0a925}, {0x0a930, 0x0a946}, {0x0a960, 0x0a97c}, {0x0a984, 0x0a9b2},
    {0x0a9cf, 0x0a9cf}, {0x0a9e0, 0x0a9e4}, {0x0a9e6, 0x0a9ef}, {0x0a9fa, 0x0a9fe},
    {0x0aa00, 0x0aa28}, {0x0aa40, 0x0aa42}, {0x0aa44, 0x0aa4b}, {0x0aa60, 0x0aa76},
    {0x0aa7a, 0x0aa7a}, {0x0aa7e, 0x0aaaf}, {0x0aab1, 0x0aab1}, {0x0aab5, 0x0aab6},
    {0x0aab9, 0x0aabd}, {0x0aac0, 0x0aac0}, {0x0aac2, 0x0aac2}, {0x0aadb, 0x0aadd},
    {0x0aae0, 0x0aaea}, {0x0aaf2, 0x0aaf4}, {0x0ab01, 0x0ab06}, {0x0ab09, 0x0ab0e},
    {0x0ab11, 0x0ab16}, {0x0ab20, 0x0ab26}, {0x0ab28, 0x0ab2e}, {0x0ab30, 0x0ab5a},
    {0x0ab5c, 0x0ab69}, {0x0ab70, 0x0abe2}, {0x0ac00, 0x0d7a3}, {0x0d7b0, 0x0d7c6},
    {0x0d7cb, 0x0d7fb}, {0x0f900, 0x0fa6d}, {0x0fa70, 0x0fad9}, {0x0fb00, 0x0fb06},
    {0x0fb13, 0x0fb17}, {0x0fb1d, 0x0fb1d}, {0x0fb1f, 0x0fb28}, {0x0fb2a, 0x0fb36},
    {0x0fb38, 0x0fb3c}, {0x0fb3e, 0x0fb3e}, {0x0fb40, 0x0fb41}, {0x0fb43, 0x0fb44},
    {0x0fb46, 0x0fbb1}, {0x0fbd3, 0x0fc5d}, {0x0fc64, 0x0fd3d}, {0x0fd50, 0x0fd8f},
    {0x0fd92, 0x0fdc7}, {0x0fdf0, 0x0fdf9}, {0x0fe71, 0x0fe71}, {0x0fe73, 0x0fe73},
    {0x0fe77, 0x0fe77}, {0x0fe79, 0x0fe79}, {0x0fe7b, 0x0fe7b}, {0x0fe7d, 0x0fe7d},
    {0x0fe7f, 0x0fefc}, {0x0ff21, 0x0ff3a}, {0x0ff41, 0x0ff5a}, {0x0ff66, 0x0ff9d},
    {0x0ffa0, 0x0ffbe}, {0x0ffc2, 0x0ffc7}, {0x0ffca, 0x0ffcf}, {0x0ffd2, 0x0ffd7},
    {0x0ffda, 0x0ffdc}, {0x10000, 0x1000b}, {0x1000d, 0x10026}, {0x10028, 0x1003a},
    {0x1003c, 0x1003d}, {0x1003f, 0x1004d}, {0x10050, 0x1005d}, {0x10080, 0x100fa},
    {0x10140, 0x10174}, {0x10280, 0x1029c}, {0x102a0, 0x102d0}, {0x10300, 0x1031f},
    {0x1032d, 0x1034a}, {0x10350, 0x10375}, {0x10380, 0x1039d}, {0x103a0, 0x103c3},
    {0x103c8, 0x103cf}, {0x103d1, 0x103d5}, {0x10400, 0x1049d}, {0x104b0, 0x104d3},
    {0x104d8, 0x104fb}, {0x10500, 0x10527}, {0x10530, 0x10563}, {0x10570, 0x1057a},
    {0x1057c, 0x1058a}, {0x1058c, 0x10592}, {0x10594, 0x10595}, {0x10597, 0x105a1},
    {0x105a3, 0x105b1}, {0x105b3, 0x105b9}, {0x105bb, 0x105bc}, {0x10600, 0x10736},
    {0x10740, 0x10755}, {0x10760, 0x10767}, {0x10780, 0x10785}, {0x10787, 0x107b0},
    {0x107b2, 0x107ba}, {0x10800, 0x10805}, {0x10808, 0x10808}, {0x1080a, 0x10835},
    {0x10837, 0x10838}, {0x1083c, 0x1083c}, {0x1083f, 0x10855}, {0x10860, 0x10876},
    {0x10880, 0x1089e}, {0x108e0, 0x108f2}, {0x108f4, 0x108f5}, {0x10900, 0x10915},
    {0x10920, 0x10939}, {0x10980, 0x109b7}, {0x109be, 0x109bf}, {0x10a00, 0x10a00},
    {0x10a10, 0x10a13}, {0x10a15, 0x10a17}, {0x10a19, 0x10a35}, {0x10a60, 0x10a7c},
    {0x10a80, 0x10a9c}, {0x10ac0, 0x10ac7}, {0x10ac9, 0x10ae4}, {0x10b00, 0x10b35},
    {0x10b40, 0x10b55}, {0x10b60, 0x10b72}, {0x10b80, 0x10b91}, {0x10c00, 0x10c48},
    {0x10c80, 0x10cb2}, {0x10cc0, 0x10cf2}, {0x10d00, 0x10d23}, {0x10e80, 0x10ea9},
    {0x10eb0, 0x10eb1}, {0x10f00, 0x10f1c}, {0x10f27, 0x10f27}, {0x10f30, 0x10f45},
    {0x10f70, 0x10f81}, {0x10fb0, 0x10fc4}, {0x10fe0, 0x10ff6}, {0x11003, 0x11037},
    {0x11071, 0x11072}, {0x11075, 0x11075}, {0x11083, 0x110af}, {0x110d0, 0x110e8},
    {0x11103, 0x11126}, {0x11144, 0x11144}, {0x11147, 0x11147}, {0x11150, 0x11172},
    {0x11176, 0x11176}, {0x11183, 0x111b2}, {0x111c1, 0x111c4}, {0x111da, 0x111da},
    {0x111dc, 0x111dc}, {0x11200, 0x11211}, {0x11213, 0x1122b}, {0x11280, 0x11286},
    {0x11288, 0x11288}, {0x1128a, 0x1128d}, {0x1128f, 0x1129d}, {0x1129f, 0x112a8},
    {0x112b0, 0x112de}, {0x11305, 0x1130c}, {0x1130f, 0x11310}, {0x11313, 0x11328},
    {0x1132a, 0x11330}, {0x11332, 0x11333}, {0x11335, 0x11339}, {0x1133d, 0x1133d},
    {0x11350, 0x11350}, {0x1135d, 0x11361}, {0x11400, 0x11434}, {0x11447, 0x1144a},
    {0x1145f, 0x11461}, {0x11480, 0x114af}, {0x114c4, 0x114c5}, {0x114c7, 0x114c7},
    {0x11580, 0x115ae}, {0x115d8, 0x115db}, {0x11600, 0x1162f}, {0x11644, 0x11644},
    {0x11680, 0x116aa}, {0x116b8, 0x116b8}, {0x11700, 0x1171a}, {0x11740, 0x11746},
    {0x11800, 0x1182b}, {0x118a0, 0x118df}, {0x118ff, 0x11906}, {0x11909, 0x11909},
    {0x1190c, 0x11913}, {0x11915, 0x11916}, {0x11918, 0x1192f}, {0x1193f, 0x1193f},
    {0x11941, 0x11941}, {0x119a0, 0x119a7}, {0x119aa, 0x119d0}, {0x119e1, 0x119e1},
    {0x119e3, 0x119e3}, {0x11a00, 0x11a00}, {0x11a0b, 0x11a32}, {0x11a3a, 0x11a3a},
    {0x11a50, 0x11a50}, {0x11a5c, 0x11a89}, {0x11a9d, 0x11a9d}, {0x11ab0, 0x11af8},
    {0x11c00, 0x11c08}, {0x11c0a, 0x11c2e}, {0x11c40, 0x11c40}, {0x11c72, 0x11c8f},
    {0x11d00, 0x11d06}, {0x11d08, 0x11d09}, {0x11d0b, 0x11d30}, {0x11d46, 0x11d46},
    {0x11d60, 0x11d65}, {0x11d67, 0x11d68}, {0x11d6a, 0x11d89}, {0x11d98, 0x11d98},
    {0x11ee0, 0x11ef2}, {0x11fb0, 0x11fb0}, {0x12000, 0x12399}, {0x12400, 0x1246e},
    {0x12480, 0x12543}, {0x12f90, 0x12ff0}, {0x13000, 0x1342e}, {0x14400, 0x14646},
    {0x16800, 0x16a38}, {0x16a40, 0x16a5e}, {0x16a70, 0x16abe}, {0x16ad0, 0x16aed},
    {0x16b00, 0x16b2f}, {0x16b40, 0x16b43}, {0x16b63, 0x16b77}, {0x16b7d, 0x16b8f},
    {0x16e40, 0x16e7f}, {0x16f00, 0x16f4a}, {0x16f50, 0x16f50}, {0x16f93, 0x16f9f},
    {0x16fe0, 0x16fe1}, {0x16fe3, 0x16fe3}, {0x17000, 0x187f7}, {0x18800, 0x18cd5},
    {0x18d00, 0x18d08}, {0x1aff0, 0x1aff3}, {0x1aff5, 0x1affb}, {0x1affd, 0x1affe},
    {0x1b000, 0x1b122}, {0x1b150, 0x1b152}, {0x1b164, 0x1b167}, {0x1b170, 0x1b2fb},
    {0x1bc00, 0x1bc6a}, {0x1bc70, 0x1bc7c}, {0x1bc80, 0x1bc88}, {0x1bc90, 0x1bc99},
    {0x1d400, 0x1d454}, {0x1d456, 0x1d49c}, {0x1d49e, 0x1d49f}, {0x1d4a2, 0x1d4a2},
    {0x1d4a5, 0x1d4a6}, {0x1d4a9, 0x1d4ac}, {0x1d4ae, 0x1d4b9}, {0x1d4bb, 0x1d4bb},
    {0x1d4bd, 0x1d4c3}, {0x1d4c5, 0x1d505}, {0x1d507, 0x1d50a}, {0x1d50d, 0x1d514},
    {0x1d516, 0x1d51c}, {0x1d51e, 0x1d539}, {0x1d53b, 0x1d53e}, {0x1d540, 0x1d544},
    {0x1d546, 0x1d546}, {0x1d54a, 0x1d550}, {0x1d552, 0x1d6a5}, {0x1d6a8, 0x1d6c0},
    {0x1d6c2, 0x1d6da}, {0x1d6dc, 0x1d6fa}, {0x1d6fc, 0x1d714}, {0x1d716, 0x1d734},
    {0x1d736, 0x1d74e}, {0x1d750, 0x1d76e}, {0x1d770, 0x1d788}, {0x1d78a, 0x1d7a8},
    {0x1d7aa, 0x1d7c2}, {0x1d7c4, 0x1d7cb}, {0x1df00, 0x1df1e}, {0x1e100, 0x1e12c},
    {0x1e137, 0x1e13d}, {0x1e14e, 0x1e14e}, {0x1e290, 0x1e2ad}, {0x1e2c0, 0x1e2eb},
    {0x1e7e0, 0x1e7e6}, {0x1e7e8, 0x1e7eb}, {0x1e7ed, 0x1e7ee}, {0x1e7f0, 0x1e7fe},
    {0x1e800, 0x1e8c4}, {0x1e900, 0x1e943}, {0x1e94b, 0x1e94b}, {0x1ee00, 0x1ee03},
    {0x1ee05, 0x1ee1f}, {0x1ee21, 0x1ee22}, {0x1ee24, 0x1ee24}, {0x1ee27, 0x1ee27},
    {0x1ee29, 0x1ee32}, {0x1ee34, 0x1ee37}, {0x1ee39, 0x1ee39}, {0x1ee3b, 0x1ee3b},
    {0x1ee42, 0x1ee42}, {0x1ee47, 0x1ee47}, {0x1ee49, 0x1ee49}, {0x1ee4b, 0x1ee4b},
    {0x1ee4d, 0x1ee4f}, {0x1ee51, 0x1ee52}, {0x1ee54, 0x1ee54}, {0x1ee57, 0x1ee57},
    {0x1ee59, 0x1ee59}, {0x1ee5b, 0x1ee5b}, {0x1ee5d, 0x1ee5d}, {0x1ee5f, 0x1ee5f},
    {0x1ee61, 0x1ee62}, {0x1ee64, 0x1ee64}, {0x1ee67, 0x1ee6a}, {0x1ee6c, 0x1ee72},
    {0x1ee74, 0x1ee77}, {0x1ee79, 0x1ee7c}, {0x1ee7e, 0x1ee7e}, {0x1ee80, 0x1ee89},
    {0x1ee8b, 0x1ee9b}, {0x1eea1, 0x1eea3}, {0x1eea5, 0x1eea9}, {0x1eeab, 0x1eebb},
    {0x20000, 0x2a6df}, {0x2a700, 0x2b738}, {0x2b740, 0x2b81d}, {0x2b820, 0x2cea1},
    {0x2ceb0, 0x2ebe0}, {0x2f800, 0x2fa1d}, {0x30000, 0x3134a},
};

// Number of ranges in kXIDStartRanges
constexpr size_t kNumXIDStartRanges = sizeof(kXIDStartRanges) / sizeof(kXIDStartRanges[0]);

// The additional code point interval ranges for the Unicode 14 XID_Continue
// set. This extends the values in kXIDStartRanges.
// This array needs to be in ascending order.
constexpr CodePointRange kXIDContinueRanges[] = {
    {0x00030, 0x00039}, {0x0005f, 0x0005f}, {0x000b7, 0x000b7}, {0x00300, 0x0036f},
    {0x00387, 0x00387}, {0x00483, 0x00487}, {0x00591, 0x005bd}, {0x005bf, 0x005bf},
    {0x005c1, 0x005c2}, {0x005c4, 0x005c5}, {0x005c7, 0x005c7}, {0x00610, 0x0061a},
    {0x0064b, 0x00669}, {0x00670, 0x00670}, {0x006d6, 0x006dc}, {0x006df, 0x006e4},
    {0x006e7, 0x006e8}, {0x006ea, 0x006ed}, {0x006f0, 0x006f9}, {0x00711, 0x00711},
    {0x00730, 0x0074a}, {0x007a6, 0x007b0}, {0x007c0, 0x007c9}, {0x007eb, 0x007f3},
    {0x007fd, 0x007fd}, {0x00816, 0x00819}, {0x0081b, 0x00823}, {0x00825, 0x00827},
    {0x00829, 0x0082d}, {0x00859, 0x0085b}, {0x00898, 0x0089f}, {0x008ca, 0x008e1},
    {0x008e3, 0x00903}, {0x0093a, 0x0093c}, {0x0093e, 0x0094f}, {0x00951, 0x00957},
    {0x00962, 0x00963}, {0x00966, 0x0096f}, {0x00981, 0x00983}, {0x009bc, 0x009bc},
    {0x009be, 0x009c4}, {0x009c7, 0x009c8}, {0x009cb, 0x009cd}, {0x009d7, 0x009d7},
    {0x009e2, 0x009e3}, {0x009e6, 0x009ef}, {0x009fe, 0x009fe}, {0x00a01, 0x00a03},
    {0x00a3c, 0x00a3c}, {0x00a3e, 0x00a42}, {0x00a47, 0x00a48}, {0x00a4b, 0x00a4d},
    {0x00a51, 0x00a51}, {0x00a66, 0x00a71}, {0x00a75, 0x00a75}, {0x00a81, 0x00a83},
    {0x00abc, 0x00abc}, {0x00abe, 0x00ac5}, {0x00ac7, 0x00ac9}, {0x00acb, 0x00acd},
    {0x00ae2, 0x00ae3}, {0x00ae6, 0x00aef}, {0x00afa, 0x00aff}, {0x00b01, 0x00b03},
    {0x00b3c, 0x00b3c}, {0x00b3e, 0x00b44}, {0x00b47, 0x00b48}, {0x00b4b, 0x00b4d},
    {0x00b55, 0x00b57}, {0x00b62, 0x00b63}, {0x00b66, 0x00b6f}, {0x00b82, 0x00b82},
    {0x00bbe, 0x00bc2}, {0x00bc6, 0x00bc8}, {0x00bca, 0x00bcd}, {0x00bd7, 0x00bd7},
    {0x00be6, 0x00bef}, {0x00c00, 0x00c04}, {0x00c3c, 0x00c3c}, {0x00c3e, 0x00c44},
    {0x00c46, 0x00c48}, {0x00c4a, 0x00c4d}, {0x00c55, 0x00c56}, {0x00c62, 0x00c63},
    {0x00c66, 0x00c6f}, {0x00c81, 0x00c83}, {0x00cbc, 0x00cbc}, {0x00cbe, 0x00cc4},
    {0x00cc6, 0x00cc8}, {0x00cca, 0x00ccd}, {0x00cd5, 0x00cd6}, {0x00ce2, 0x00ce3},
    {0x00ce6, 0x00cef}, {0x00d00, 0x00d03}, {0x00d3b, 0x00d3c}, {0x00d3e, 0x00d44},
    {0x00d46, 0x00d48}, {0x00d4a, 0x00d4d}, {0x00d57, 0x00d57}, {0x00d62, 0x00d63},
    {0x00d66, 0x00d6f}, {0x00d81, 0x00d83}, {0x00dca, 0x00dca}, {0x00dcf, 0x00dd4},
    {0x00dd6, 0x00dd6}, {0x00dd8, 0x00ddf}, {0x00de6, 0x00def}, {0x00df2, 0x00df3},
    {0x00e31, 0x00e31}, {0x00e33, 0x00e3a}, {0x00e47, 0x00e4e}, {0x00e50, 0x00e59},
    {0x00eb1, 0x00eb1}, {0x00eb3, 0x00ebc}, {0x00ec8, 0x00ecd}, {0x00ed0, 0x00ed9},
    {0x00f18, 0x00f19}, {0x00f20, 0x00f29}, {0x00f35, 0x00f35}, {0x00f37, 0x00f37},
    {0x00f39, 0x00f39}, {0x00f3e, 0x00f3f}, {0x00f71, 0x00f84}, {0x00f86, 0x00f87},
    {0x00f8d, 0x00f97}, {0x00f99, 0x00fbc}, {0x00fc6, 0x00fc6}, {0x0102b, 0x0103e},
    {0x01040, 0x01049}, {0x01056, 0x01059}, {0x0105e, 0x01060}, {0x01062, 0x01064},
    {0x01067, 0x0106d}, {0x01071, 0x01074}, {0x01082, 0x0108d}, {0x0108f, 0x0109d},
    {0x0135d, 0x0135f}, {0x01369, 0x01371}, {0x01712, 0x01715}, {0x01732, 0x01734},
    {0x01752, 0x01753}, {0x01772, 0x01773}, {0x017b4, 0x017d3}, {0x017dd, 0x017dd},
    {0x017e0, 0x017e9}, {0x0180b, 0x0180d}, {0x0180f, 0x01819}, {0x018a9, 0x018a9},
    {0x01920, 0x0192b}, {0x01930, 0x0193b}, {0x01946, 0x0194f}, {0x019d0, 0x019da},
    {0x01a17, 0x01a1b}, {0x01a55, 0x01a5e}, {0x01a60, 0x01a7c}, {0x01a7f, 0x01a89},
    {0x01a90, 0x01a99}, {0x01ab0, 0x01abd}, {0x01abf, 0x01ace}, {0x01b00, 0x01b04},
    {0x01b34, 0x01b44}, {0x01b50, 0x01b59}, {0x01b6b, 0x01b73}, {0x01b80, 0x01b82},
    {0x01ba1, 0x01bad}, {0x01bb0, 0x01bb9}, {0x01be6, 0x01bf3}, {0x01c24, 0x01c37},
    {0x01c40, 0x01c49}, {0x01c50, 0x01c59}, {0x01cd0, 0x01cd2}, {0x01cd4, 0x01ce8},
    {0x01ced, 0x01ced}, {0x01cf4, 0x01cf4}, {0x01cf7, 0x01cf9}, {0x01dc0, 0x01dff},
    {0x0203f, 0x02040}, {0x02054, 0x02054}, {0x020d0, 0x020dc}, {0x020e1, 0x020e1},
    {0x020e5, 0x020f0}, {0x02cef, 0x02cf1}, {0x02d7f, 0x02d7f}, {0x02de0, 0x02dff},
    {0x0302a, 0x0302f}, {0x03099, 0x0309a}, {0x0a620, 0x0a629}, {0x0a66f, 0x0a66f},
    {0x0a674, 0x0a67d}, {0x0a69e, 0x0a69f}, {0x0a6f0, 0x0a6f1}, {0x0a802, 0x0a802},
    {0x0a806, 0x0a806}, {0x0a80b, 0x0a80b}, {0x0a823, 0x0a827}, {0x0a82c, 0x0a82c},
    {0x0a880, 0x0a881}, {0x0a8b4, 0x0a8c5}, {0x0a8d0, 0x0a8d9}, {0x0a8e0, 0x0a8f1},
    {0x0a8ff, 0x0a909}, {0x0a926, 0x0a92d}, {0x0a947, 0x0a953}, {0x0a980, 0x0a983},
    {0x0a9b3, 0x0a9c0}, {0x0a9d0, 0x0a9d9}, {0x0a9e5, 0x0a9e5}, {0x0a9f0, 0x0a9f9},
    {0x0aa29, 0x0aa36}, {0x0aa43, 0x0aa43}, {0x0aa4c, 0x0aa4d}, {0x0aa50, 0x0aa59},
    {0x0aa7b, 0x0aa7d}, {0x0aab0, 0x0aab0}, {0x0aab2, 0x0aab4}, {0x0aab7, 0x0aab8},
    {0x0aabe, 0x0aabf}, {0x0aac1, 0x0aac1}, {0x0aaeb, 0x0aaef}, {0x0aaf5, 0x0aaf6},
    {0x0abe3, 0x0abea}, {0x0abec, 0x0abed}, {0x0abf0, 0x0abf9}, {0x0fb1e, 0x0fb1e},
    {0x0fe00, 0x0fe0f}, {0x0fe20, 0x0fe2f}, {0x0fe33, 0x0fe34}, {0x0fe4d, 0x0fe4f},
    {0x0ff10, 0x0ff19}, {0x0ff3f, 0x0ff3f}, {0x0ff9e, 0x0ff9f}, {0x101fd, 0x101fd},
    {0x102e0, 0x102e0}, {0x10376, 0x1037a}, {0x104a0, 0x104a9}, {0x10a01, 0x10a03},
    {0x10a05, 0x10a06}, {0x10a0c, 0x10a0f}, {0x10a38, 0x10a3a}, {0x10a3f, 0x10a3f},
    {0x10ae5, 0x10ae6}, {0x10d24, 0x10d27}, {0x10d30, 0x10d39}, {0x10eab, 0x10eac},
    {0x10f46, 0x10f50}, {0x10f82, 0x10f85}, {0x11000, 0x11002}, {0x11038, 0x11046},
    {0x11066, 0x11070}, {0x11073, 0x11074}, {0x1107f, 0x11082}, {0x110b0, 0x110ba},
    {0x110c2, 0x110c2}, {0x110f0, 0x110f9}, {0x11100, 0x11102}, {0x11127, 0x11134},
    {0x11136, 0x1113f}, {0x11145, 0x11146}, {0x11173, 0x11173}, {0x11180, 0x11182},
    {0x111b3, 0x111c0}, {0x111c9, 0x111cc}, {0x111ce, 0x111d9}, {0x1122c, 0x11237},
    {0x1123e, 0x1123e}, {0x112df, 0x112ea}, {0x112f0, 0x112f9}, {0x11300, 0x11303},
    {0x1133b, 0x1133c}, {0x1133e, 0x11344}, {0x11347, 0x11348}, {0x1134b, 0x1134d},
    {0x11357, 0x11357}, {0x11362, 0x11363}, {0x11366, 0x1136c}, {0x11370, 0x11374},
    {0x11435, 0x11446}, {0x11450, 0x11459}, {0x1145e, 0x1145e}, {0x114b0, 0x114c3},
    {0x114d0, 0x114d9}, {0x115af, 0x115b5}, {0x115b8, 0x115c0}, {0x115dc, 0x115dd},
    {0x11630, 0x11640}, {0x11650, 0x11659}, {0x116ab, 0x116b7}, {0x116c0, 0x116c9},
    {0x1171d, 0x1172b}, {0x11730, 0x11739}, {0x1182c, 0x1183a}, {0x118e0, 0x118e9},
    {0x11930, 0x11935}, {0x11937, 0x11938}, {0x1193b, 0x1193e}, {0x11940, 0x11940},
    {0x11942, 0x11943}, {0x11950, 0x11959}, {0x119d1, 0x119d7}, {0x119da, 0x119e0},
    {0x119e4, 0x119e4}, {0x11a01, 0x11a0a}, {0x11a33, 0x11a39}, {0x11a3b, 0x11a3e},
    {0x11a47, 0x11a47}, {0x11a51, 0x11a5b}, {0x11a8a, 0x11a99}, {0x11c2f, 0x11c36},
    {0x11c38, 0x11c3f}, {0x11c50, 0x11c59}, {0x11c92, 0x11ca7}, {0x11ca9, 0x11cb6},
    {0x11d31, 0x11d36}, {0x11d3a, 0x11d3a}, {0x11d3c, 0x11d3d}, {0x11d3f, 0x11d45},
    {0x11d47, 0x11d47}, {0x11d50, 0x11d59}, {0x11d8a, 0x11d8e}, {0x11d90, 0x11d91},
    {0x11d93, 0x11d97}, {0x11da0, 0x11da9}, {0x11ef3, 0x11ef6}, {0x16a60, 0x16a69},
    {0x16ac0, 0x16ac9}, {0x16af0, 0x16af4}, {0x16b30, 0x16b36}, {0x16b50, 0x16b59},
    {0x16f4f, 0x16f4f}, {0x16f51, 0x16f87}, {0x16f8f, 0x16f92}, {0x16fe4, 0x16fe4},
    {0x16ff0, 0x16ff1}, {0x1bc9d, 0x1bc9e}, {0x1cf00, 0x1cf2d}, {0x1cf30, 0x1cf46},
    {0x1d165, 0x1d169}, {0x1d16d, 0x1d172}, {0x1d17b, 0x1d182}, {0x1d185, 0x1d18b},
    {0x1d1aa, 0x1d1ad}, {0x1d242, 0x1d244}, {0x1d7ce, 0x1d7ff}, {0x1da00, 0x1da36},
    {0x1da3b, 0x1da6c}, {0x1da75, 0x1da75}, {0x1da84, 0x1da84}, {0x1da9b, 0x1da9f},
    {0x1daa1, 0x1daaf}, {0x1e000, 0x1e006}, {0x1e008, 0x1e018}, {0x1e01b, 0x1e021},
    {0x1e023, 0x1e024}, {0x1e026, 0x1e02a}, {0x1e130, 0x1e136}, {0x1e140, 0x1e149},
    {0x1e2ae, 0x1e2ae}, {0x1e2ec, 0x1e2f9}, {0x1e8d0, 0x1e8d6}, {0x1e944, 0x1e94a},
    {0x1e950, 0x1e959}, {0x1fbf0, 0x1fbf9}, {0xe0100, 0xe01ef},
};

// Number of ranges in kXIDContinueRanges
constexpr size_t kNumXIDContinueRanges = sizeof(kXIDContinueRanges) / sizeof(kXIDContinueRanges[0]);

}  // namespace

bool CodePoint::IsXIDStart() const {
    // Short circuit ASCII. The binary search will find these last, but most
    // of our current source is ASCII, so handle them quicker.
    if ((value >= 'a' && value <= 'z') || (value >= 'A' && value <= 'Z')) {
        return true;
    }
    // With [a-zA-Z] handled, nothing less then the next sequence start can be
    // XIDStart, so filter them all out. This catches most of the common symbols
    // that are used in ASCII.
    if (value < 0x000aa) {
        return false;
    }
    return std::binary_search(kXIDStartRanges, kXIDStartRanges + kNumXIDStartRanges, *this);
}

bool CodePoint::IsXIDContinue() const {
    // Short circuit ASCII. The binary search will find these last, but most
    // of our current source is ASCII, so handle them quicker.
    if ((value >= '0' && value <= '9') || value == '_') {
        return true;
    }
    return IsXIDStart() || std::binary_search(kXIDContinueRanges,
                                              kXIDContinueRanges + kNumXIDContinueRanges, *this);
}

namespace utf8 {

std::pair<CodePoint, size_t> Decode(const uint8_t* ptr, size_t len) {
    if (len < 1) {
        return {};
    }
    // Fast-path ASCII characters as they're always valid
    if (ptr[0] <= 0x7f) {
        return {CodePoint{ptr[0]}, 1};
    }

    // Lookup table for the first byte of a UTF-8 sequence.
    // 0 indicates an invalid length.
    // Note that bit encodings that can fit in a smaller number of bytes are
    // invalid (e.g. 0xc0). Code points that exceed the unicode maximum of
    // 0x10FFFF are also invalid (0xf5+).
    // See: https://en.wikipedia.org/wiki/UTF-8#Encoding and
    //      https://datatracker.ietf.org/doc/html/rfc3629#section-3
    static constexpr uint8_t kSequenceLength[256] = {
        //         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
        /* 0x00 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x10 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x20 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x30 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x40 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x50 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x60 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x70 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
        /* 0x80 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        /* 0x90 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        /* 0xa0 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        /* 0xb0 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        /* 0xc0 */ 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
        /* 0xd0 */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
        /* 0xe0 */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
        /* 0xf0 */ 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    };

    uint8_t n = kSequenceLength[ptr[0]];
    if (n > len) {
        return {};
    }

    CodePoint c;

    uint8_t top_bits = 0b11000000;
    switch (n) {
        // Note: n=0 (invalid) is correctly handled without a case.
        case 1:
            c = CodePoint{ptr[0]};
            break;
        case 2:
            top_bits &= ptr[1] ^ 0b01000000;
            c = CodePoint{(static_cast<uint32_t>(ptr[0] & 0b00011111) << 6) |
                          (static_cast<uint32_t>(ptr[1] & 0b00111111))};
            break;
        case 3:
            top_bits &= (ptr[1] ^ 0b01000000) & (ptr[2] ^ 0b01000000);
            c = CodePoint{(static_cast<uint32_t>(ptr[0] & 0b00001111) << 12) |
                          (static_cast<uint32_t>(ptr[1] & 0b00111111) << 6) |
                          (static_cast<uint32_t>(ptr[2] & 0b00111111))};
            break;
        case 4:
            top_bits &= (ptr[1] ^ 0b01000000) & (ptr[2] ^ 0b01000000) & (ptr[3] ^ 0b01000000);
            c = CodePoint{(static_cast<uint32_t>(ptr[0] & 0b00000111) << 18) |
                          (static_cast<uint32_t>(ptr[1] & 0b00111111) << 12) |
                          (static_cast<uint32_t>(ptr[2] & 0b00111111) << 6) |
                          (static_cast<uint32_t>(ptr[3] & 0b00111111))};
            break;
    }
    if (top_bits != 0b11000000) {
        // Check that the two most significant bits of all the code units after the first code point
        // are all [1, 0].
        n = 0;
        c = 0;
    }
    return {c, n};
}

std::pair<CodePoint, size_t> Decode(std::string_view utf8_string) {
    return Decode(reinterpret_cast<const uint8_t*>(utf8_string.data()), utf8_string.size());
}

size_t Encode(CodePoint code_point, uint8_t* ptr) {
    if (code_point <= 0x7f) {
        if (ptr) {
            ptr[0] = static_cast<uint8_t>(code_point);
        }
        return 1;
    }
    if (code_point <= 0x7ff) {
        if (ptr) {
            ptr[0] = static_cast<uint8_t>(code_point >> 6) | 0b11000000;
            ptr[1] = static_cast<uint8_t>(code_point & 0b00111111) | 0b10000000;
        }
        return 2;
    }
    if (code_point <= 0xffff) {
        if (ptr) {
            ptr[0] = static_cast<uint8_t>(code_point >> 12) | 0b11100000;
            ptr[1] = static_cast<uint8_t>((code_point >> 6) & 0b00111111) | 0b10000000;
            ptr[2] = static_cast<uint8_t>(code_point & 0b00111111) | 0b10000000;
        }
        return 3;
    }
    if (code_point <= 0x10ffff) {
        if (ptr) {
            ptr[0] = static_cast<uint8_t>(code_point >> 18) | 0b11110000;
            ptr[1] = static_cast<uint8_t>((code_point >> 12) & 0b00111111) | 0b10000000;
            ptr[2] = static_cast<uint8_t>((code_point >> 6) & 0b00111111) | 0b10000000;
            ptr[3] = static_cast<uint8_t>(code_point & 0b00111111) | 0b10000000;
        }
        return 4;
    }
    return 0;  // invalid code point
}

bool IsASCII(std::string_view str) {
    for (auto c : str) {
        if (c & 0x80) {
            return false;
        }
    }
    return true;
}

}  // namespace utf8

namespace utf16 {

std::pair<CodePoint, size_t> Decode(const uint16_t* ptr, size_t len) {
    if (len < 1) {
        return {};
    }
    uint16_t a = ptr[0];
    if (a <= 0xd7ff || a >= 0xe000) {
        return {CodePoint{static_cast<uint32_t>(a)}, 1};
    }
    if (len < 2) {
        return {};
    }
    uint32_t b = ptr[1];
    if (b <= 0xd7ff || b >= 0xe000) {
        return {};
    }
    uint32_t high = a - 0xd800;
    uint32_t low = b - 0xdc00;
    return {CodePoint{0x10000 + ((high << 10) | low)}, 2};
}

std::pair<CodePoint, size_t> Decode(std::string_view utf16_string) {
    return Decode(reinterpret_cast<const uint16_t*>(utf16_string.data()), utf16_string.size() / 2);
}

size_t Encode(CodePoint code_point, uint16_t* ptr) {
    if (code_point <= 0xd7ff || (code_point >= 0xe000 && code_point <= 0xffff)) {
        if (ptr) {
            ptr[0] = static_cast<uint16_t>(code_point);
        }
        return 1;
    }
    if (code_point >= 0x10000 && code_point <= 0x10ffff) {
        if (ptr) {
            auto biased = code_point - 0x10000;
            ptr[0] = static_cast<uint16_t>((biased >> 10) + 0xd800);
            ptr[1] = static_cast<uint16_t>((biased & 0b1111111111) + 0xdc00);
        }
        return 2;
    }
    return 0;  // invalid code point
}

}  // namespace utf16
}  // namespace tint