79 lines
1.7 KiB
C++
Executable File
79 lines
1.7 KiB
C++
Executable File
/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
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* Use of this file is governed by the BSD 3-clause license that
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* can be found in the LICENSE.txt file in the project root.
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*/
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#include "Token.h"
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#include "CommonTokenStream.h"
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using namespace antlr4;
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CommonTokenStream::CommonTokenStream(TokenSource *tokenSource) : CommonTokenStream(tokenSource, Token::DEFAULT_CHANNEL) {
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}
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CommonTokenStream::CommonTokenStream(TokenSource *tokenSource, size_t channel_)
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: BufferedTokenStream(tokenSource), channel(channel_) {
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}
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ssize_t CommonTokenStream::adjustSeekIndex(size_t i) {
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return nextTokenOnChannel(i, channel);
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}
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Token* CommonTokenStream::LB(size_t k) {
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if (k == 0 || k > _p) {
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return nullptr;
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}
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ssize_t i = static_cast<ssize_t>(_p);
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size_t n = 1;
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// find k good tokens looking backwards
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while (n <= k) {
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// skip off-channel tokens
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i = previousTokenOnChannel(i - 1, channel);
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n++;
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}
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if (i < 0) {
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return nullptr;
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}
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return _tokens[i].get();
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}
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Token* CommonTokenStream::LT(ssize_t k) {
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lazyInit();
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if (k == 0) {
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return nullptr;
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}
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if (k < 0) {
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return LB(static_cast<size_t>(-k));
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}
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size_t i = _p;
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ssize_t n = 1; // we know tokens[p] is a good one
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// find k good tokens
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while (n < k) {
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// skip off-channel tokens, but make sure to not look past EOF
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if (sync(i + 1)) {
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i = nextTokenOnChannel(i + 1, channel);
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}
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n++;
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}
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return _tokens[i].get();
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}
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int CommonTokenStream::getNumberOfOnChannelTokens() {
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int n = 0;
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fill();
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for (size_t i = 0; i < _tokens.size(); i++) {
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Token *t = _tokens[i].get();
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if (t->getChannel() == channel) {
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n++;
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}
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if (t->getType() == Token::EOF) {
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break;
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}
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}
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return n;
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}
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