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Diffstat (limited to 'intl/icu/source/extra/scrptrun/scrptrun.cpp')
| -rw-r--r-- | intl/icu/source/extra/scrptrun/scrptrun.cpp | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/intl/icu/source/extra/scrptrun/scrptrun.cpp b/intl/icu/source/extra/scrptrun/scrptrun.cpp new file mode 100644 index 0000000000..4fd8de1b85 --- /dev/null +++ b/intl/icu/source/extra/scrptrun/scrptrun.cpp @@ -0,0 +1,206 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* + ******************************************************************************* + * + * Copyright (C) 1999-2016, International Business Machines + * Corporation and others. All Rights Reserved. + * + ******************************************************************************* + * file name: scrptrun.cpp + * + * created on: 10/17/2001 + * created by: Eric R. Mader + */ + +#include "unicode/utypes.h" +#include "unicode/uscript.h" + +#include "cmemory.h" +#include "scrptrun.h" + +U_NAMESPACE_BEGIN + +const char ScriptRun::fgClassID=0; + +UChar32 ScriptRun::pairedChars[] = { + 0x0028, 0x0029, // ascii paired punctuation + 0x003c, 0x003e, + 0x005b, 0x005d, + 0x007b, 0x007d, + 0x00ab, 0x00bb, // guillemets + 0x2018, 0x2019, // general punctuation + 0x201c, 0x201d, + 0x2039, 0x203a, + 0x3008, 0x3009, // chinese paired punctuation + 0x300a, 0x300b, + 0x300c, 0x300d, + 0x300e, 0x300f, + 0x3010, 0x3011, + 0x3014, 0x3015, + 0x3016, 0x3017, + 0x3018, 0x3019, + 0x301a, 0x301b +}; + +const int32_t ScriptRun::pairedCharCount = UPRV_LENGTHOF(pairedChars); +const int32_t ScriptRun::pairedCharPower = 1 << highBit(pairedCharCount); +const int32_t ScriptRun::pairedCharExtra = pairedCharCount - pairedCharPower; + +int8_t ScriptRun::highBit(int32_t value) +{ + if (value <= 0) { + return -32; + } + + int8_t bit = 0; + + if (value >= 1 << 16) { + value >>= 16; + bit += 16; + } + + if (value >= 1 << 8) { + value >>= 8; + bit += 8; + } + + if (value >= 1 << 4) { + value >>= 4; + bit += 4; + } + + if (value >= 1 << 2) { + value >>= 2; + bit += 2; + } + + if (value >= 1 << 1) { + value >>= 1; + bit += 1; + } + + return bit; +} + +int32_t ScriptRun::getPairIndex(UChar32 ch) +{ + int32_t probe = pairedCharPower; + int32_t index = 0; + + if (ch >= pairedChars[pairedCharExtra]) { + index = pairedCharExtra; + } + + while (probe > (1 << 0)) { + probe >>= 1; + + if (ch >= pairedChars[index + probe]) { + index += probe; + } + } + + if (pairedChars[index] != ch) { + index = -1; + } + + return index; +} + +UBool ScriptRun::sameScript(int32_t scriptOne, int32_t scriptTwo) +{ + return scriptOne <= USCRIPT_INHERITED || scriptTwo <= USCRIPT_INHERITED || scriptOne == scriptTwo; +} + +UBool ScriptRun::next() +{ + int32_t startSP = parenSP; // used to find the first new open character + UErrorCode error = U_ZERO_ERROR; + + // if we've fallen off the end of the text, we're done + if (scriptEnd >= charLimit) { + return false; + } + + scriptCode = USCRIPT_COMMON; + + for (scriptStart = scriptEnd; scriptEnd < charLimit; scriptEnd += 1) { + char16_t high = charArray[scriptEnd]; + UChar32 ch = high; + + // if the character is a high surrogate and it's not the last one + // in the text, see if it's followed by a low surrogate + if (high >= 0xD800 && high <= 0xDBFF && scriptEnd < charLimit - 1) + { + char16_t low = charArray[scriptEnd + 1]; + + // if it is followed by a low surrogate, + // consume it and form the full character + if (low >= 0xDC00 && low <= 0xDFFF) { + ch = (high - 0xD800) * 0x0400 + low - 0xDC00 + 0x10000; + scriptEnd += 1; + } + } + + UScriptCode sc = uscript_getScript(ch, &error); + int32_t pairIndex = getPairIndex(ch); + + // Paired character handling: + // + // if it's an open character, push it onto the stack. + // if it's a close character, find the matching open on the + // stack, and use that script code. Any non-matching open + // characters above it on the stack will be poped. + if (pairIndex >= 0) { + if ((pairIndex & 1) == 0) { + parenStack[++parenSP].pairIndex = pairIndex; + parenStack[parenSP].scriptCode = scriptCode; + } else if (parenSP >= 0) { + int32_t pi = pairIndex & ~1; + + while (parenSP >= 0 && parenStack[parenSP].pairIndex != pi) { + parenSP -= 1; + } + + if (parenSP < startSP) { + startSP = parenSP; + } + + if (parenSP >= 0) { + sc = parenStack[parenSP].scriptCode; + } + } + } + + if (sameScript(scriptCode, sc)) { + if (scriptCode <= USCRIPT_INHERITED && sc > USCRIPT_INHERITED) { + scriptCode = sc; + + // now that we have a final script code, fix any open + // characters we pushed before we knew the script code. + while (startSP < parenSP) { + parenStack[++startSP].scriptCode = scriptCode; + } + } + + // if this character is a close paired character, + // pop it from the stack + if (pairIndex >= 0 && (pairIndex & 1) != 0 && parenSP >= 0) { + parenSP -= 1; + startSP -= 1; + } + } else { + // if the run broke on a surrogate pair, + // end it before the high surrogate + if (ch >= 0x10000) { + scriptEnd -= 1; + } + + break; + } + } + + return true; +} + +U_NAMESPACE_END |