1 /* 2 ******************************************************************************* 3 * 4 * Copyright (C) 1999-2001, International Business Machines 5 * Corporation and others. All Rights Reserved. 6 * 7 ******************************************************************************* 8 * file name: scrptrun.cpp 9 * 10 * created on: 10/17/2001 11 * created by: Eric R. Mader 12 */ 13 14 #include "unicode/utypes.h" 15 #include "unicode/uscript.h" 16 17 #include "scrptrun.h" 18 19 #define ARRAY_SIZE(array) (sizeof array / sizeof array[0]) 20 21 const char ScriptRun::fgClassID=0; 22 23 UChar32 ScriptRun::pairedChars[] = { 24 0x0028, 0x0029, // ascii paired punctuation 25 0x003c, 0x003e, 26 0x005b, 0x005d, 27 0x007b, 0x007d, 28 0x00ab, 0x00bb, // guillemets 29 0x2018, 0x2019, // general punctuation 30 0x201c, 0x201d, 31 0x2039, 0x203a, 32 0x3008, 0x3009, // chinese paired punctuation 33 0x300a, 0x300b, 34 0x300c, 0x300d, 35 0x300e, 0x300f, 36 0x3010, 0x3011, 37 0x3014, 0x3015, 38 0x3016, 0x3017, 39 0x3018, 0x3019, 40 0x301a, 0x301b 41 }; 42 43 const int32_t ScriptRun::pairedCharCount = ARRAY_SIZE(pairedChars); 44 const int32_t ScriptRun::pairedCharPower = 1 << highBit(pairedCharCount); 45 const int32_t ScriptRun::pairedCharExtra = pairedCharCount - pairedCharPower; 46 47 int8_t ScriptRun::highBit(int32_t value) 48 { 49 if (value <= 0) { 50 return -32; 51 } 52 53 int8_t bit = 0; 54 55 if (value >= 1 << 16) { 56 value >>= 16; 57 bit += 16; 58 } 59 60 if (value >= 1 << 8) { 61 value >>= 8; 62 bit += 8; 63 } 64 65 if (value >= 1 << 4) { 66 value >>= 4; 67 bit += 4; 68 } 69 70 if (value >= 1 << 2) { 71 value >>= 2; 72 bit += 2; 73 } 74 75 if (value >= 1 << 1) { 76 value >>= 1; 77 bit += 1; 78 } 79 80 return bit; 81 } 82 83 int32_t ScriptRun::getPairIndex(UChar32 ch) 84 { 85 int32_t probe = pairedCharPower; 86 int32_t index = 0; 87 88 if (ch >= pairedChars[pairedCharExtra]) { 89 index = pairedCharExtra; 90 } 91 92 while (probe > (1 << 0)) { 93 probe >>= 1; 94 95 if (ch >= pairedChars[index + probe]) { 96 index += probe; 97 } 98 } 99 100 if (pairedChars[index] != ch) { 101 index = -1; 102 } 103 104 return index; 105 } 106 107 UBool ScriptRun::sameScript(int32_t scriptOne, int32_t scriptTwo) 108 { 109 return scriptOne <= USCRIPT_INHERITED || scriptTwo <= USCRIPT_INHERITED || scriptOne == scriptTwo; 110 } 111 112 UBool ScriptRun::next() 113 { 114 int32_t startSP = parenSP; // used to find the first new open character 115 UErrorCode error = U_ZERO_ERROR; 116 117 // if we've fallen off the end of the text, we're done 118 if (scriptEnd >= charLimit) { 119 return false; 120 } 121 122 scriptCode = USCRIPT_COMMON; 123 124 for (scriptStart = scriptEnd; scriptEnd < charLimit; scriptEnd += 1) { 125 UChar high = charArray[scriptEnd]; 126 UChar32 ch = high; 127 128 // if the character is a high surrogate and it's not the last one 129 // in the text, see if it's followed by a low surrogate 130 if (high >= 0xD800 && high <= 0xDBFF && scriptEnd < charLimit - 1) 131 { 132 UChar low = charArray[scriptEnd + 1]; 133 134 // if it is followed by a low surrogate, 135 // consume it and form the full character 136 if (low >= 0xDC00 && low <= 0xDFFF) { 137 ch = (high - 0xD800) * 0x0400 + low - 0xDC00 + 0x10000; 138 scriptEnd += 1; 139 } 140 } 141 142 UScriptCode sc = uscript_getScript(ch, &error); 143 int32_t pairIndex = getPairIndex(ch); 144 145 // Paired character handling: 146 // 147 // if it's an open character, push it onto the stack. 148 // if it's a close character, find the matching open on the 149 // stack, and use that script code. Any non-matching open 150 // characters above it on the stack will be poped. 151 if (pairIndex >= 0) { 152 if ((pairIndex & 1) == 0) { 153 parenStack[++parenSP].pairIndex = pairIndex; 154 parenStack[parenSP].scriptCode = scriptCode; 155 } else if (parenSP >= 0) { 156 int32_t pi = pairIndex & ~1; 157 158 while (parenSP >= 0 && parenStack[parenSP].pairIndex != pi) { 159 parenSP -= 1; 160 } 161 162 if (parenSP < startSP) { 163 startSP = parenSP; 164 } 165 166 if (parenSP >= 0) { 167 sc = parenStack[parenSP].scriptCode; 168 } 169 } 170 } 171 172 if (sameScript(scriptCode, sc)) { 173 if (scriptCode <= USCRIPT_INHERITED && sc > USCRIPT_INHERITED) { 174 scriptCode = sc; 175 176 // now that we have a final script code, fix any open 177 // characters we pushed before we knew the script code. 178 while (startSP < parenSP) { 179 parenStack[++startSP].scriptCode = scriptCode; 180 } 181 } 182 183 // if this character is a close paired character, 184 // pop it from the stack 185 if (pairIndex >= 0 && (pairIndex & 1) != 0 && parenSP >= 0) { 186 parenSP -= 1; 187 startSP -= 1; 188 } 189 } else { 190 // if the run broke on a surrogate pair, 191 // end it before the high surrogate 192 if (ch >= 0x10000) { 193 scriptEnd -= 1; 194 } 195 196 break; 197 } 198 } 199 200 return true; 201 } 202 203
