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/* tnt/parser.h
* Copyright (C) 2003-2005 Tommi Maekitalo
*
* This program 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 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* is provided AS IS, WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, and
* NON-INFRINGEMENT. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifndef TNT_PARSER_H
#define TNT_PARSER_H
#include <iostream>
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;
bool failedFlag;
public:
explicit Parser(state_type initialState)
: state(initialState),
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)
{
char ch;
while (in.get(ch))
if (parse(ch))
return true;
return false;
}
bool failed() const
{
return failedFlag;
}
};
}
#endif // TNT_PARSER_H
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