Sha256: 200f10480606ae9589f25667183a8961d9ad38fd22cc9932fadc5321450b8f8a
Contents?: true
Size: 1.86 KB
Versions: 19
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Stored size: 1.86 KB
Contents
/* 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 "support/CPPUtils.h"
#include "support/Casts.h"
#include "tree/ParseTreeListener.h"
#include "tree/ParseTree.h"
#include "tree/ErrorNode.h"
#include "IterativeParseTreeWalker.h"
using namespace antlr4::tree;
using namespace antlrcpp;
void IterativeParseTreeWalker::walk(ParseTreeListener *listener, ParseTree *t) const {
std::vector<std::pair<ParseTree*, size_t>> stack;
ParseTree *currentNode = t;
size_t currentIndex = 0;
while (currentNode != nullptr) {
// pre-order visit
if (ErrorNode::is(*currentNode)) {
listener->visitErrorNode(downCast<ErrorNode*>(currentNode));
} else if (TerminalNode::is(*currentNode)) {
listener->visitTerminal(downCast<TerminalNode*>(currentNode));
} else {
enterRule(listener, currentNode);
}
// Move down to first child, if it exists.
if (!currentNode->children.empty()) {
stack.push_back(std::make_pair(currentNode, currentIndex));
currentIndex = 0;
currentNode = currentNode->children[0];
continue;
}
// No child nodes, so walk tree.
do {
// post-order visit
if (!TerminalNode::is(*currentNode)) {
exitRule(listener, currentNode);
}
// No parent, so no siblings.
if (stack.empty()) {
currentNode = nullptr;
currentIndex = 0;
break;
}
// Move to next sibling if possible.
if (stack.back().first->children.size() > ++currentIndex) {
currentNode = stack.back().first->children[currentIndex];
break;
}
// No next sibling, so move up.
std::tie(currentNode, currentIndex) = stack.back();
stack.pop_back();
} while (currentNode != nullptr);
}
}
Version data entries
19 entries across 19 versions & 3 rubygems