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/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
#include "Exceptions.h"
#include "RuleContext.h"
#include "Token.h"
#include "TokenSource.h"
#include "WritableToken.h"
#include "assert.h"
#include "misc/Interval.h"
#include "support/Arrays.h"
#include "UnbufferedTokenStream.h"
using namespace antlr4;
UnbufferedTokenStream::UnbufferedTokenStream(TokenSource* tokenSource)
: UnbufferedTokenStream(tokenSource, 256) {}
UnbufferedTokenStream::UnbufferedTokenStream(TokenSource* tokenSource,
int /*bufferSize*/)
: _tokenSource(tokenSource),
_lastToken(nullptr),
_lastTokenBufferStart(nullptr) {
InitializeInstanceFields();
fill(1); // prime the pump
}
UnbufferedTokenStream::~UnbufferedTokenStream() {}
Token* UnbufferedTokenStream::get(size_t i) const { // get absolute index
size_t bufferStartIndex = getBufferStartIndex();
if (i < bufferStartIndex || i >= bufferStartIndex + _tokens.size()) {
throw IndexOutOfBoundsException(
std::string("get(") + std::to_string(i) +
std::string(") outside buffer: ") + std::to_string(bufferStartIndex) +
std::string("..") + std::to_string(bufferStartIndex + _tokens.size()));
}
return _tokens[i - bufferStartIndex].get();
}
Token* UnbufferedTokenStream::LT(ssize_t i) {
if (i == -1) {
return _lastToken;
}
sync(i);
ssize_t index = static_cast<ssize_t>(_p) + i - 1;
if (index < 0) {
throw IndexOutOfBoundsException(std::string("LT(") + std::to_string(i) +
std::string(") gives negative index"));
}
if (index >= static_cast<ssize_t>(_tokens.size())) {
assert(_tokens.size() > 0 && _tokens.back()->getType() == EOF);
return _tokens.back().get();
}
return _tokens[static_cast<size_t>(index)].get();
}
size_t UnbufferedTokenStream::LA(ssize_t i) { return LT(i)->getType(); }
TokenSource* UnbufferedTokenStream::getTokenSource() const {
return _tokenSource;
}
std::string UnbufferedTokenStream::getText() { return ""; }
std::string UnbufferedTokenStream::getText(RuleContext* ctx) {
return getText(ctx->getSourceInterval());
}
std::string UnbufferedTokenStream::getText(Token* start, Token* stop) {
return getText(misc::Interval(start->getTokenIndex(), stop->getTokenIndex()));
}
void UnbufferedTokenStream::consume() {
if (LA(1) == EOF) {
throw IllegalStateException("cannot consume EOF");
}
// buf always has at least tokens[p==0] in this method due to ctor
_lastToken = _tokens[_p].get(); // track last token for LT(-1)
// if we're at last token and no markers, opportunity to flush buffer
if (_p == _tokens.size() - 1 && _numMarkers == 0) {
_tokens.clear();
_p = 0;
_lastTokenBufferStart = _lastToken;
} else {
++_p;
}
++_currentTokenIndex;
sync(1);
}
/// <summary>
/// Make sure we have 'need' elements from current position <seealso cref="#p
/// p"/>. Last valid
/// {@code p} index is {@code tokens.length-1}. {@code p+need-1} is the tokens
/// index 'need' elements ahead. If we need 1 element, {@code (p+1-1)==p} must
/// be less than {@code tokens.length}.
/// </summary>
void UnbufferedTokenStream::sync(ssize_t want) {
ssize_t need = (static_cast<ssize_t>(_p) + want - 1) -
static_cast<ssize_t>(_tokens.size()) +
1; // how many more elements we need?
if (need > 0) {
fill(static_cast<size_t>(need));
}
}
/// <summary>
/// Add {@code n} elements to the buffer. Returns the number of tokens
/// actually added to the buffer. If the return value is less than {@code n},
/// then EOF was reached before {@code n} tokens could be added.
/// </summary>
size_t UnbufferedTokenStream::fill(size_t n) {
for (size_t i = 0; i < n; i++) {
if (_tokens.size() > 0 && _tokens.back()->getType() == EOF) {
return i;
}
add(_tokenSource->nextToken());
}
return n;
}
void UnbufferedTokenStream::add(std::unique_ptr<Token> t) {
WritableToken* writable = dynamic_cast<WritableToken*>(t.get());
if (writable != nullptr) {
writable->setTokenIndex(int(getBufferStartIndex() + _tokens.size()));
}
_tokens.push_back(std::move(t));
}
/// <summary>
/// Return a marker that we can release later.
/// <p/>
/// The specific marker value used for this class allows for some level of
/// protection against misuse where {@code seek()} is called on a mark or
/// {@code release()} is called in the wrong order.
/// </summary>
ssize_t UnbufferedTokenStream::mark() {
if (_numMarkers == 0) {
_lastTokenBufferStart = _lastToken;
}
int mark = -_numMarkers - 1;
_numMarkers++;
return mark;
}
void UnbufferedTokenStream::release(ssize_t marker) {
ssize_t expectedMark = -_numMarkers;
if (marker != expectedMark) {
throw IllegalStateException("release() called with an invalid marker.");
}
_numMarkers--;
if (_numMarkers == 0) { // can we release buffer?
if (_p > 0) {
// Copy tokens[p]..tokens[n-1] to tokens[0]..tokens[(n-1)-p], reset ptrs
// p is last valid token; move nothing if p==n as we have no valid char
_tokens.erase(_tokens.begin(),
_tokens.begin() + static_cast<ssize_t>(_p));
_p = 0;
}
_lastTokenBufferStart = _lastToken;
}
}
size_t UnbufferedTokenStream::index() { return _currentTokenIndex; }
void UnbufferedTokenStream::seek(size_t index) { // seek to absolute index
if (index == _currentTokenIndex) {
return;
}
if (index > _currentTokenIndex) {
sync(ssize_t(index - _currentTokenIndex));
index = std::min(index, getBufferStartIndex() + _tokens.size() - 1);
}
size_t bufferStartIndex = getBufferStartIndex();
if (bufferStartIndex > index) {
throw IllegalArgumentException(
std::string("cannot seek to negative index ") + std::to_string(index));
}
size_t i = index - bufferStartIndex;
if (i >= _tokens.size()) {
throw UnsupportedOperationException(
std::string("seek to index outside buffer: ") + std::to_string(index) +
" not in " + std::to_string(bufferStartIndex) + ".." +
std::to_string(bufferStartIndex + _tokens.size()));
}
_p = i;
_currentTokenIndex = index;
if (_p == 0) {
_lastToken = _lastTokenBufferStart;
} else {
_lastToken = _tokens[_p - 1].get();
}
}
size_t UnbufferedTokenStream::size() {
throw UnsupportedOperationException("Unbuffered stream cannot know its size");
}
std::string UnbufferedTokenStream::getSourceName() const {
return _tokenSource->getSourceName();
}
std::string UnbufferedTokenStream::getText(const misc::Interval& interval) {
size_t bufferStartIndex = getBufferStartIndex();
size_t bufferStopIndex = bufferStartIndex + _tokens.size() - 1;
size_t start = interval.a;
size_t stop = interval.b;
if (start < bufferStartIndex || stop > bufferStopIndex) {
throw UnsupportedOperationException(
std::string("interval ") + interval.toString() +
" not in token buffer window: " + std::to_string(bufferStartIndex) +
".." + std::to_string(bufferStopIndex));
}
size_t a = start - bufferStartIndex;
size_t b = stop - bufferStartIndex;
std::stringstream ss;
for (size_t i = a; i <= b; i++) {
Token* t = _tokens[i].get();
if (i > 0) ss << ", ";
ss << t->getText();
}
return ss.str();
}
size_t UnbufferedTokenStream::getBufferStartIndex() const {
return _currentTokenIndex - _p;
}
void UnbufferedTokenStream::InitializeInstanceFields() {
_p = 0;
_numMarkers = 0;
_currentTokenIndex = 0;
}
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