src/util/regex/regex-pattern-list-matcher.hpp

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/**
 * Copyright (c) 2013-2014,  Regents of the University of California.
 * All rights reserved.
 *
 * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
 *
 * This file licensed under New BSD License.  See COPYING for detailed information about
 * ndn-cxx library copyright, permissions, and redistribution restrictions.
 *
 * @author Yingdi Yu <http://irl.cs.ucla.edu/~yingdi/>
 */

#ifndef NDN_UTIL_REGEX_REGEX_PATTERN_LIST_MATCHER_HPP
#define NDN_UTIL_REGEX_REGEX_PATTERN_LIST_MATCHER_HPP

#include "../../common.hpp"

#include "regex-matcher.hpp"

namespace ndn {

class RegexBackrefManager;

class RegexPatternListMatcher : public RegexMatcher
{
public:
  RegexPatternListMatcher(const std::string& expr, shared_ptr<RegexBackrefManager> backRefManager);

  virtual ~RegexPatternListMatcher(){};

protected:
  virtual void
  compile();

private:
  bool
  extractPattern(int index, int* next);

  int
  extractSubPattern(const char left, const char right, size_t index);

  int
  extractRepetition(size_t index);

private:

};

} // namespace ndn

#include "regex-repeat-matcher.hpp"
#include "regex-backref-matcher.hpp"

namespace ndn {

inline
RegexPatternListMatcher::RegexPatternListMatcher(const std::string& expr,
                                                 shared_ptr<RegexBackrefManager> backrefManager)
  : RegexMatcher(expr, EXPR_PATTERNLIST, backrefManager)
{
  compile();
}

inline void
RegexPatternListMatcher::compile()
{
  const int len = m_expr.size();
  int index = 0;
  int subHead = index;

  while(index < len){
    subHead = index;

    if (!extractPattern(subHead, &index))
      throw RegexMatcher::Error("RegexPatternListMatcher compile: cannot compile");
  }
}

inline bool
RegexPatternListMatcher::extractPattern(int index, int* next)
{
  // std::string errMsg = "Error: RegexPatternListMatcher.ExtractSubPattern(): ";

  const int start = index;
  int end = index;
  int indicator = index;

  switch (m_expr[index]){
  case '(':
    index++;
    index = extractSubPattern('(', ')', index);
    indicator = index;
    end = extractRepetition(index);
    if (indicator == end){
      shared_ptr<RegexMatcher> matcher =
        make_shared<RegexBackrefMatcher>(m_expr.substr(start, end - start), m_backrefManager);
      m_backrefManager->pushRef(matcher);
      dynamic_pointer_cast<RegexBackrefMatcher>(matcher)->lateCompile();

      m_matcherList.push_back(matcher);
    }
    else
      m_matcherList.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_matcherList.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_matcherList.push_back(make_shared<RegexRepeatMatcher>(m_expr.substr(start, end - start),
                                                            m_backrefManager, indicator - start));
    break;

  default:
    throw RegexMatcher::Error("Error: unexpected syntax");
  }

  *next = end;

  return true;
}

inline int
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())
      throw RegexMatcher::Error("Error: parenthesis mismatch");

    if (left == m_expr[index])
      lcount++;

    if (right == m_expr[index])
      rcount++;

    index++;
  }
  return index;
}

inline int
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)
      throw RegexMatcher::Error(std::string("Error: RegexPatternListMatcher.ExtractRepetition(): ")
                                + "Missing right brace bracket");
    else
      return ++index;
  }
  else {
    return index;
  }
}


} // namespace ndn

#endif // NDN_UTIL_REGEX_REGEX_PATTERN_LIST_MATCHER_HPP