Boost.Regex: sub

Boost.Regex

sub_match

Synopsis

Regular expressions are different from many simple pattern-matching algorithms in that as well as finding an overall match they can also produce sub-expression matches: each sub-expression being delimited in the pattern by a pair of parenthesis (...). There has to be some method for reporting sub-expression matches back to the user: this is achieved this by defining a class match_results that acts as an indexed collection of sub-expression matches, each sub-expression match being contained in an object of type sub_match .

Objects of type sub_match may only obtained by subscripting an object of type match_results .

When the marked sub-expression denoted by an object of type sub_match<> participated in a regular expression match then member matched evaluates to true, and members first and second denote the range of characters [first,second) which formed that match. Otherwise matched is false, and members first and second contained undefined values.

If an object of type sub_match<> represents sub-expression 0 - that is to say the whole match - then member matched is always true, unless a partial match was obtained as a result of the flag match_partial being passed to a regular expression algorithm, in which case member matched is false, and members first and second represent the character range that formed the partial match.

namespace boost{
      
template <class BidirectionalIterator>
class sub_match : public std::pair<BidirectionalIterator, BidirectionalIterator>
{
public:
   typedef typename iterator_traits<BidirectionalIterator>::value_type       value_type;
   typedef typename iterator_traits<BidirectionalIterator>::difference_type  difference_type;
   typedef          BidirectionalIterator                                    iterator;

   bool matched;

   difference_type length()const;
   operator basic_string<value_type>()const;
   basic_string<value_type> str()const;

   int compare(const sub_match& s)const;
   int compare(const basic_string<value_type>& s)const;
   int compare(const value_type* s)const;
};

template <class BidirectionalIterator>
bool operator == (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator>
bool operator != (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator>
bool operator < (const sub_match<BidirectionalIterator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator>
bool operator <= (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator>
bool operator >= (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator>
bool operator > (const sub_match<BidirectionalIterator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);


template <class BidirectionalIterator, class traits, class Allocator> 
bool operator == (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator != (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator < (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator > (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator >= (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator <= (const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);

template <class BidirectionalIterator, class traits, class Allocator> 
bool operator == (const sub_match<BidirectionalIterator>& lhs,
                  const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator != (const sub_match<BidirectionalIterator>& lhs,
                  const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator < (const sub_match<BidirectionalIterator>& lhs,
                 const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator > (const sub_match<BidirectionalIterator>& lhs,
                 const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator >= (const sub_match<BidirectionalIterator>& lhs,
                  const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);
template <class BidirectionalIterator, class traits, class Allocator> 
bool operator <= (const sub_match<BidirectionalIterator>& lhs,
                  const std::basic_string<iterator_traits<BidirectionalIterator>::value_type, traits, Allocator>& rhs);

template <class BidirectionalIterator> 
bool operator == (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator != (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator < (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                 const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator > (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                 const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator >= (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator <= (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 

template <class BidirectionalIterator> 
bool operator == (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 
template <class BidirectionalIterator> 
bool operator != (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 
template <class BidirectionalIterator> 
bool operator < (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 
template <class BidirectionalIterator> 
bool operator > (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 
template <class BidirectionalIterator> 
bool operator >= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 
template <class BidirectionalIterator> 
bool operator <= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs); 

template <class BidirectionalIterator> 
bool operator == (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator != (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator < (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                 const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator > (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                 const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator >= (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 
template <class BidirectionalIterator> 
bool operator <= (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs); 

template <class BidirectionalIterator> 
bool operator == (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 
template <class BidirectionalIterator> 
bool operator != (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 
template <class BidirectionalIterator> 
bool operator < (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 
template <class BidirectionalIterator> 
bool operator > (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 
template <class BidirectionalIterator> 
bool operator >= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 
template <class BidirectionalIterator> 
bool operator <= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs); 

template <class charT, class traits, class BidirectionalIterator>
basic_ostream<charT, traits>&
   operator << (basic_ostream<charT, traits>& os,
                const sub_match<BidirectionalIterator>& m);

} // namespace boost

Description

sub_match members

typedef typename std::iterator_traits<iterator>::value_type value_type;

The type pointed to by the iterators.

typedef typename std::iterator_traits<iterator>::difference_type difference_type;

A type that represents the difference between two iterators.

typedef iterator iterator_type;

The iterator type.

iterator first

An iterator denoting the position of the start of the match.

iterator second

An iterator denoting the position of the end of the match.

bool matched

A Boolean value denoting whether this sub-expression participated in the match.

static difference_type length();

Effects: returns (matched ? 0 : distance(first, second)).

operator basic_string<value_type>()const;

Effects: returns (matched ? basic_string<value_type>(first, second) : basic_string<value_type>()).

basic_string<value_type> str()const;

Effects: returns (matched ? basic_string<value_type>(first, second) : basic_string<value_type>()).

int compare(const sub_match& s)const;

Effects: returns str().compare(s.str()).

int compare(const basic_string<value_type>& s)const;

Effects: returns str().compare(s).

int compare(const value_type* s)const;

Effects: returns str().compare(s).

sub_match non-member operators

template <class BidirectionalIterator>
bool operator == (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) == 0.

template <class BidirectionalIterator>
bool operator != (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) != 0.

template <class BidirectionalIterator>
bool operator < (const sub_match<BidirectionalIterator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) < 0.

template <class BidirectionalIterator>
bool operator <= (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) <= 0.

template <class BidirectionalIterator>
bool operator >= (const sub_match<BidirectionalIterator>& lhs,
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) >= 0.

template <class BidirectionalIterator>
bool operator > (const sub_match<BidirectionalIterator>& lhs,
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs.compare(rhs) > 0.

template <class BidirectionalIterator> 
bool operator == (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs == rhs.str().

template <class BidirectionalIterator> 
bool operator != (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs != rhs.str().

template <class BidirectionalIterator> 
bool operator < (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs < rhs.str().

template <class BidirectionalIterator> 
bool operator > (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs > rhs.str().

template <class BidirectionalIterator> 
bool operator >= (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs >= rhs.str().

template <class BidirectionalIterator> 
bool operator <= (typename iterator_traits<BidirectionalIterator>::value_type const* lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs <= rhs.str().

template <class BidirectionalIterator> 
bool operator == (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() == rhs.

template <class BidirectionalIterator> 
bool operator != (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() != rhs.

template <class BidirectionalIterator> 
bool operator < (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() < rhs.

template <class BidirectionalIterator> 
bool operator > (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() > rhs.

template <class BidirectionalIterator> 
bool operator >= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() >= rhs.

template <class BidirectionalIterator> 
bool operator <= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const* rhs);

Effects: returns lhs.str() <= rhs.

template <class BidirectionalIterator> 
bool operator == (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs == rhs.str().

template <class BidirectionalIterator> 
bool operator != (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs != rhs.str().

template <class BidirectionalIterator> 
bool operator < (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs < rhs.str().

template <class BidirectionalIterator> 
bool operator > (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                 const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs > rhs.str().

template <class BidirectionalIterator> 
bool operator >= (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs >= rhs.str().

template <class BidirectionalIterator> 
bool operator <= (typename iterator_traits<BidirectionalIterator>::value_type const& lhs, 
                  const sub_match<BidirectionalIterator>& rhs);

Effects: returns lhs <= rhs.str().

template <class BidirectionalIterator> 
bool operator == (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() == rhs.

template <class BidirectionalIterator> 
bool operator != (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() != rhs.

template <class BidirectionalIterator> 
bool operator < (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() < rhs.

template <class BidirectionalIterator> 
bool operator > (const sub_match<BidirectionalIterator>& lhs, 
                 typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() > rhs.

template <class BidirectionalIterator> 
bool operator >= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() >= rhs.

template <class BidirectionalIterator> 
bool operator <= (const sub_match<BidirectionalIterator>& lhs, 
                  typename iterator_traits<BidirectionalIterator>::value_type const& rhs);

Effects: returns lhs.str() <= rhs.

template <class charT, class traits, class BidirectionalIterator>
basic_ostream<charT, traits>&
   operator << (basic_ostream<charT, traits>& os
                const sub_match<BidirectionalIterator>& m);

Effects: returns (os << m.str()).

Revised 17 May 2003

Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. Dr John Maddock makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.