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/*
* Copyright (C) 2003-2005 Tommi Maekitalo
*
* This 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 2.1 of the License, or (at your option) any later version.
*
* As a special exception, you may use this file as part of a free
* software library without restriction. Specifically, if other files
* instantiate templates or use macros or inline functions from this
* file, or you compile this file and link it with other files to
* produce an executable, this file does not by itself cause the
* resulting executable to be covered by the GNU General Public
* License. This exception does not however invalidate any other
* reasons why the executable file might be covered by the GNU Library
* General Public License.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef TNT_PARSER_H
#define TNT_PARSER_H
#include <iostream>
/// @cond internal
namespace tnt
{
class PrePostNop
{
protected:
void pre(char /* ch */) { }
bool post(bool ret) { return ret; }
};
template <typename this_type, class PrePostProcessor = PrePostNop>
class Parser : public PrePostProcessor
{
protected:
typedef bool (this_type::*state_type)(char);
state_type _state;
state_type _nextState;
bool _failedFlag;
bool state_skipws(char ch)
{
if (ch != ' ' && ch != '\t')
{
_state = _nextState;
return (static_cast<this_type*>(this)->*_state)(ch);
}
else
return false;
}
void skipWs(state_type nextState)
{
_state = &Parser::state_skipws;
_nextState = nextState;
}
public:
explicit Parser(state_type initialState)
: _state(initialState),
_nextState(0),
_failedFlag(false)
{ }
bool parse(char ch)
{
PrePostProcessor::pre(ch);
return PrePostProcessor::post(
(static_cast<this_type*>(this)->*_state)(ch) );
}
bool parse(const char* str, unsigned size)
{
for (unsigned s = 0; s < size; ++s)
if (parse(str[s]))
return true;
return false;
}
bool parse(std::istream& in)
{
std::streambuf* buf = in.rdbuf();
while (buf->sgetc() != std::ios::traits_type::eof())
if ( parse(buf->sbumpc()) )
return true;
in.setstate(std::ios::eofbit);
return false;
}
bool failed() const { return _failedFlag; }
};
}
#endif // TNT_PARSER_H
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