regex-matcher.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
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4  *
5  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
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21  * @author Yingdi Yu <http://irl.cs.ucla.edu/~yingdi/>
22  */
23 
25 
26 namespace ndn {
27 
28 RegexMatcher::RegexMatcher(const std::string& expr, RegexExprType type,
29  shared_ptr<RegexBackrefManager> backrefManager)
30  : m_expr(expr)
31  , m_type(type)
32 {
33  if (backrefManager)
34  m_backrefManager = std::move(backrefManager);
35  else
36  m_backrefManager = make_shared<RegexBackrefManager>();
37 }
38 
39 RegexMatcher::~RegexMatcher() = default;
40 
41 bool
42 RegexMatcher::match(const Name& name, size_t offset, size_t len)
43 {
44  m_matchResult.clear();
45 
46  if (recursiveMatch(0, name, offset, len)) {
47  for (size_t i = offset; i < offset + len; i++)
48  m_matchResult.push_back(name.get(i));
49  return true;
50  }
51 
52  return false;
53 }
54 
55 bool
56 RegexMatcher::recursiveMatch(size_t matcherNo, const Name& name, size_t offset, size_t len)
57 {
58  if (matcherNo >= m_matchers.size())
59  return len == 0;
60 
61  ssize_t tried = len;
62  auto matcher = m_matchers[matcherNo];
63 
64  while (tried >= 0) {
65  if (matcher->match(name, offset, tried) &&
66  recursiveMatch(matcherNo + 1, name, offset + tried, len - tried))
67  return true;
68  tried--;
69  }
70 
71  return false;
72 }
73 
74 std::ostream&
75 operator<<(std::ostream& os, const RegexMatcher& rm)
76 {
77  return os << rm.getExpr();
78 }
79 
80 } // namespace ndn
Represents an absolute name.
Definition: name.hpp:45
const Component & get(ssize_t i) const noexcept
Returns an immutable reference to the component at the specified index.
Definition: name.hpp:192
virtual ~RegexMatcher()
std::vector< name::Component > m_matchResult
RegexMatcher(const std::string &expr, RegexExprType type, shared_ptr< RegexBackrefManager > backrefManager=nullptr)
virtual bool match(const Name &name, size_t offset, size_t len)
const std::string & getExpr() const
shared_ptr< RegexBackrefManager > m_backrefManager
std::vector< shared_ptr< RegexMatcher > > m_matchers
Definition: data.cpp:25
std::ostream & operator<<(std::ostream &os, const Data &data)
Definition: data.cpp:377