regex_automaton.tcc
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// class template regex -*- C++ -*-
// Copyright (C) 2013-2014 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This 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 General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/**
* @file bits/regex_automaton.tcc
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{regex}
*/
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace __detail
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#ifdef _GLIBCXX_DEBUG
std::ostream&
_State_base::_M_print(std::ostream& ostr) const
{
switch (_M_opcode)
{
case _S_opcode_alternative:
ostr << "alt next=" << _M_next << " alt=" << _M_alt;
break;
case _S_opcode_subexpr_begin:
ostr << "subexpr begin next=" << _M_next << " index=" << _M_subexpr;
break;
case _S_opcode_subexpr_end:
ostr << "subexpr end next=" << _M_next << " index=" << _M_subexpr;
break;
case _S_opcode_backref:
ostr << "backref next=" << _M_next << " index=" << _M_backref_index;
break;
case _S_opcode_match:
ostr << "match next=" << _M_next;
break;
case _S_opcode_accept:
ostr << "accept next=" << _M_next;
break;
default:
ostr << "unknown next=" << _M_next;
break;
}
return ostr;
}
// Prints graphviz dot commands for state.
std::ostream&
_State_base::_M_dot(std::ostream& __ostr, _StateIdT __id) const
{
switch (_M_opcode)
{
case _S_opcode_alternative:
__ostr << __id << " [label=\"" << __id << "\\nALT\"];\n"
<< __id << " -> " << _M_next
<< " [label=\"epsilon\", tailport=\"s\"];\n"
<< __id << " -> " << _M_alt
<< " [label=\"epsilon\", tailport=\"n\"];\n";
break;
case _S_opcode_backref:
__ostr << __id << " [label=\"" << __id << "\\nBACKREF "
<< _M_subexpr << "\"];\n"
<< __id << " -> " << _M_next << " [label=\"<match>\"];\n";
break;
case _S_opcode_line_begin_assertion:
__ostr << __id << " [label=\"" << __id << "\\nLINE_BEGIN \"];\n"
<< __id << " -> " << _M_next << " [label=\"epsilon\"];\n";
break;
case _S_opcode_line_end_assertion:
__ostr << __id << " [label=\"" << __id << "\\nLINE_END \"];\n"
<< __id << " -> " << _M_next << " [label=\"epsilon\"];\n";
break;
case _S_opcode_word_boundary:
__ostr << __id << " [label=\"" << __id << "\\nWORD_BOUNDRY "
<< _M_neg << "\"];\n"
<< __id << " -> " << _M_next << " [label=\"epsilon\"];\n";
break;
case _S_opcode_subexpr_lookahead:
__ostr << __id << " [label=\"" << __id << "\\nLOOK_AHEAD\"];\n"
<< __id << " -> " << _M_next
<< " [label=\"epsilon\", tailport=\"s\"];\n"
<< __id << " -> " << _M_alt
<< " [label=\"<assert>\", tailport=\"n\"];\n";
break;
case _S_opcode_subexpr_begin:
__ostr << __id << " [label=\"" << __id << "\\nSBEGIN "
<< _M_subexpr << "\"];\n"
<< __id << " -> " << _M_next << " [label=\"epsilon\"];\n";
break;
case _S_opcode_subexpr_end:
__ostr << __id << " [label=\"" << __id << "\\nSEND "
<< _M_subexpr << "\"];\n"
<< __id << " -> " << _M_next << " [label=\"epsilon\"];\n";
break;
case _S_opcode_dummy:
break;
case _S_opcode_match:
__ostr << __id << " [label=\"" << __id << "\\nMATCH\"];\n"
<< __id << " -> " << _M_next << " [label=\"<match>\"];\n";
break;
case _S_opcode_accept:
__ostr << __id << " [label=\"" << __id << "\\nACC\"];\n" ;
break;
default:
_GLIBCXX_DEBUG_ASSERT(false);
break;
}
return __ostr;
}
template<typename _TraitsT>
std::ostream&
_NFA<_TraitsT>::_M_dot(std::ostream& __ostr) const
{
__ostr << "digraph _Nfa {\n"
" rankdir=LR;\n";
for (size_t __i = 0; __i < this->size(); ++__i)
(*this)[__i]._M_dot(__ostr, __i);
__ostr << "}\n";
return __ostr;
}
#endif
template<typename _TraitsT>
_StateIdT
_NFA<_TraitsT>::_M_insert_backref(size_t __index)
{
// To figure out whether a backref is valid, a stack is used to store
// unfinished sub-expressions. For example, when parsing
// "(a(b)(c\\1(d)))" at '\\1', _M_subexpr_count is 3, indicating that 3
// sub expressions are parsed or partially parsed(in the stack), aka,
// "(a..", "(b)" and "(c..").
// _M_paren_stack is {1, 3}, for incomplete "(a.." and "(c..". At this
// time, "\\2" is valid, but "\\1" and "\\3" are not.
if (__index >= _M_subexpr_count)
__throw_regex_error(regex_constants::error_backref);
for (auto __it : this->_M_paren_stack)
if (__index == __it)
__throw_regex_error(regex_constants::error_backref);
this->_M_has_backref = true;
_StateT __tmp(_S_opcode_backref);
__tmp._M_backref_index = __index;
return _M_insert_state(std::move(__tmp));
}
template<typename _TraitsT>
void
_NFA<_TraitsT>::_M_eliminate_dummy()
{
for (auto& __it : *this)
{
while (__it._M_next >= 0 && (*this)[__it._M_next]._M_opcode
== _S_opcode_dummy)
__it._M_next = (*this)[__it._M_next]._M_next;
if (__it._M_opcode == _S_opcode_alternative
|| __it._M_opcode == _S_opcode_subexpr_lookahead)
while (__it._M_alt >= 0 && (*this)[__it._M_alt]._M_opcode
== _S_opcode_dummy)
__it._M_alt = (*this)[__it._M_alt]._M_next;
}
}
// Just apply DFS on the sequence and re-link their links.
template<typename _TraitsT>
_StateSeq<_TraitsT>
_StateSeq<_TraitsT>::_M_clone()
{
std::map<_StateIdT, _StateIdT> __m;
std::stack<_StateIdT> __stack;
__stack.push(_M_start);
while (!__stack.empty())
{
auto __u = __stack.top();
__stack.pop();
auto __dup = _M_nfa[__u];
auto __id = _M_nfa._M_insert_state(__dup);
__m[__u] = __id;
if (__u == _M_end)
continue;
if (__m.count(__dup._M_next) == 0)
__stack.push(__dup._M_next);
if (__dup._M_opcode == _S_opcode_alternative
|| __dup._M_opcode == _S_opcode_subexpr_lookahead)
if (__m.count(__dup._M_alt) == 0)
__stack.push(__dup._M_alt);
}
for (auto __it : __m)
{
auto& __ref = _M_nfa[__it.second];
if (__ref._M_next != -1)
{
_GLIBCXX_DEBUG_ASSERT(__m.count(__ref._M_next));
__ref._M_next = __m[__ref._M_next];
}
if (__ref._M_opcode == _S_opcode_alternative
|| __ref._M_opcode == _S_opcode_subexpr_lookahead)
if (__ref._M_alt != -1)
{
_GLIBCXX_DEBUG_ASSERT(__m.count(__ref._M_alt));
__ref._M_alt = __m[__ref._M_alt];
}
}
return _StateSeq(_M_nfa, __m[_M_start], __m[_M_end]);
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace __detail
} // namespace
std::size
constexpr size_t size() const noexcept
Returns the total number of bits.
Definition: bitset:1293
std::map::count
size_type count(const key_type &__x) const
Finds the number of elements with given key.
Definition: stl_map.h:885
std::stack::top
reference top()
Definition: stl_stack.h:159
std::map
A standard container made up of (key,value) pairs, which can be retrieved based on a key...
Definition: stl_map.h:96
std::stack::pop
void pop()
Removes first element.
Definition: stl_stack.h:212
std::regex_constants::error_backref
constexpr error_type error_backref(_S_error_backref)
std::stack::push
void push(const value_type &__x)
Add data to the top of the stack.
Definition: stl_stack.h:186
std::basic_ostream< char >
std::stack
A standard container giving FILO behavior.
Definition: stl_stack.h:96