163 lines
4.4 KiB
C++
163 lines
4.4 KiB
C++
// © 2016 and later: Unicode, Inc. and others.
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// License & terms of use: http://www.unicode.org/copyright.html
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/*
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**********************************************************************
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* Copyright (c) 2003-2011, International Business Machines
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* Corporation and others. All Rights Reserved.
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**********************************************************************
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* Author: Alan Liu
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* Created: September 24 2003
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* Since: ICU 2.8
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**********************************************************************
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*/
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#include "ruleiter.h"
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#include "unicode/parsepos.h"
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#include "unicode/symtable.h"
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#include "unicode/unistr.h"
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#include "unicode/utf16.h"
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#include "patternprops.h"
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/* \U87654321 or \ud800\udc00 */
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#define MAX_U_NOTATION_LEN 12
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U_NAMESPACE_BEGIN
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RuleCharacterIterator::RuleCharacterIterator(const UnicodeString& theText, const SymbolTable* theSym,
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ParsePosition& thePos) :
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text(theText),
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pos(thePos),
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sym(theSym),
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buf(nullptr),
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bufPos(0)
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{}
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UBool RuleCharacterIterator::atEnd() const {
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return buf == nullptr && pos.getIndex() == text.length();
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}
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UChar32 RuleCharacterIterator::next(int32_t options, UBool& isEscaped, UErrorCode& ec) {
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if (U_FAILURE(ec)) return DONE;
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UChar32 c = DONE;
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isEscaped = false;
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for (;;) {
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c = _current();
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_advance(U16_LENGTH(c));
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if (c == SymbolTable::SYMBOL_REF && buf == nullptr &&
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(options & PARSE_VARIABLES) != 0 && sym != nullptr) {
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UnicodeString name = sym->parseReference(text, pos, text.length());
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// If name is empty there was an isolated SYMBOL_REF;
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// return it. Caller must be prepared for this.
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if (name.length() == 0) {
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break;
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}
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bufPos = 0;
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buf = sym->lookup(name);
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if (buf == nullptr) {
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ec = U_UNDEFINED_VARIABLE;
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return DONE;
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}
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// Handle empty variable value
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if (buf->length() == 0) {
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buf = nullptr;
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}
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continue;
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}
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if ((options & SKIP_WHITESPACE) != 0 && PatternProps::isWhiteSpace(c)) {
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continue;
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}
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if (c == 0x5C /*'\\'*/ && (options & PARSE_ESCAPES) != 0) {
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UnicodeString tempEscape;
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int32_t offset = 0;
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c = lookahead(tempEscape, MAX_U_NOTATION_LEN).unescapeAt(offset);
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jumpahead(offset);
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isEscaped = true;
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if (c < 0) {
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ec = U_MALFORMED_UNICODE_ESCAPE;
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return DONE;
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}
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}
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break;
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}
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return c;
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}
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void RuleCharacterIterator::getPos(RuleCharacterIterator::Pos& p) const {
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p.buf = buf;
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p.pos = pos.getIndex();
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p.bufPos = bufPos;
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}
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void RuleCharacterIterator::setPos(const RuleCharacterIterator::Pos& p) {
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buf = p.buf;
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pos.setIndex(p.pos);
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bufPos = p.bufPos;
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}
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void RuleCharacterIterator::skipIgnored(int32_t options) {
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if ((options & SKIP_WHITESPACE) != 0) {
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for (;;) {
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UChar32 a = _current();
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if (!PatternProps::isWhiteSpace(a)) break;
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_advance(U16_LENGTH(a));
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}
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}
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}
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UnicodeString& RuleCharacterIterator::lookahead(UnicodeString& result, int32_t maxLookAhead) const {
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if (maxLookAhead < 0) {
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maxLookAhead = 0x7FFFFFFF;
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}
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if (buf != nullptr) {
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buf->extract(bufPos, maxLookAhead, result);
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} else {
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text.extract(pos.getIndex(), maxLookAhead, result);
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}
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return result;
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}
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void RuleCharacterIterator::jumpahead(int32_t count) {
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_advance(count);
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}
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/*
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UnicodeString& RuleCharacterIterator::toString(UnicodeString& result) const {
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int32_t b = pos.getIndex();
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text.extract(0, b, result);
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return result.append((char16_t) 0x7C).append(text, b, 0x7FFFFFFF); // Insert '|' at index
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}
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*/
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UChar32 RuleCharacterIterator::_current() const {
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if (buf != nullptr) {
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return buf->char32At(bufPos);
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} else {
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int i = pos.getIndex();
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return (i < text.length()) ? text.char32At(i) : (UChar32)DONE;
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}
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}
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void RuleCharacterIterator::_advance(int32_t count) {
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if (buf != nullptr) {
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bufPos += count;
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if (bufPos == buf->length()) {
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buf = nullptr;
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}
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} else {
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pos.setIndex(pos.getIndex() + count);
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if (pos.getIndex() > text.length()) {
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pos.setIndex(text.length());
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}
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}
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}
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U_NAMESPACE_END
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//eof
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