blob: 1923875fdc68c7767745651bf0eb87889e5b1f76 [file] [log] [blame]
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2018 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx library is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*
* @author Yingdi Yu <http://irl.cs.ucla.edu/~yingdi/>
*/
#include "ndn-cxx/util/regex/regex-pattern-list-matcher.hpp"
#include "ndn-cxx/util/regex/regex-backref-matcher.hpp"
#include "ndn-cxx/util/regex/regex-repeat-matcher.hpp"
namespace ndn {
RegexPatternListMatcher::RegexPatternListMatcher(const std::string& expr,
shared_ptr<RegexBackrefManager> backrefManager)
: RegexMatcher(expr, EXPR_PATTERN_LIST, std::move(backrefManager))
{
compile();
}
void
RegexPatternListMatcher::compile()
{
size_t len = m_expr.size();
size_t index = 0;
size_t subHead = index;
while (index < len) {
subHead = index;
if (!extractPattern(subHead, &index))
BOOST_THROW_EXCEPTION(Error("Compile error"));
}
}
bool
RegexPatternListMatcher::extractPattern(size_t index, size_t* next)
{
size_t start = index;
size_t end = index;
size_t indicator = index;
switch (m_expr[index]) {
case '(':
index++;
index = extractSubPattern('(', ')', index);
indicator = index;
end = extractRepetition(index);
if (indicator == end) {
auto matcher = make_shared<RegexBackrefMatcher>(m_expr.substr(start, end - start),
m_backrefManager);
m_backrefManager->pushRef(matcher);
matcher->lateCompile();
m_matchers.push_back(std::move(matcher));
}
else
m_matchers.push_back(make_shared<RegexRepeatMatcher>(m_expr.substr(start, end - start),
m_backrefManager, indicator - start));
break;
case '<':
index++;
index = extractSubPattern('<', '>', index);
indicator = index;
end = extractRepetition(index);
m_matchers.push_back(make_shared<RegexRepeatMatcher>(m_expr.substr(start, end - start),
m_backrefManager, indicator - start));
break;
case '[':
index++;
index = extractSubPattern('[', ']', index);
indicator = index;
end = extractRepetition(index);
m_matchers.push_back(make_shared<RegexRepeatMatcher>(m_expr.substr(start, end - start),
m_backrefManager, indicator - start));
break;
default:
BOOST_THROW_EXCEPTION(Error("Unexpected syntax"));
}
*next = end;
return true;
}
size_t
RegexPatternListMatcher::extractSubPattern(const char left, const char right, size_t index)
{
size_t lcount = 1;
size_t rcount = 0;
while (lcount > rcount) {
if (index >= m_expr.size())
BOOST_THROW_EXCEPTION(Error("Parenthesis mismatch"));
if (left == m_expr[index])
lcount++;
if (right == m_expr[index])
rcount++;
index++;
}
return index;
}
size_t
RegexPatternListMatcher::extractRepetition(size_t index)
{
size_t exprSize = m_expr.size();
if (index == exprSize)
return index;
if (('+' == m_expr[index] || '?' == m_expr[index] || '*' == m_expr[index])) {
return ++index;
}
if ('{' == m_expr[index]) {
while ('}' != m_expr[index]) {
index++;
if (index == exprSize)
break;
}
if (index == exprSize)
BOOST_THROW_EXCEPTION(Error("Missing right brace bracket"));
else
return ++index;
}
else {
return index;
}
}
} // namespace ndn