kicad/include/ptree.h

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#ifndef PTREE_H_
#define PTREE_H_
/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2013 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
* Copyright (C) 2013 KiCad Developers, see CHANGELOG.TXT for contributors.
*
* 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 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/*
Implement "KiCad s-epression" support for boost::property_tree's ptree, the 8
bit string version of property_tree. The ram resident structure of the ptree is
mostly compatible with one created using the xml_parser from
boost::property_tree, with slight differences in the way atoms are stored. The
result is you can use Format() to convert from xml to s-expression, but not the
other way around. You can write a simple s-expression beautifier in just a few
lines of code.
The main value however is the s-expression parser, i.e. Scan(), which is an
alternative to crafting a custom recursive descent parser for a particular
grammar. The tipping point depends on whether you want to read only a small
portion of a much larger document. If so, then using the ptree will likely be a
"faster to code" route. Documentation on how to navigate a ptree can be found on
the boost website and there are a number of examples in the
pcbnew/eagle_plugin.cpp file in this project. Powerful path navigation support
makes it easy to extract a subset of a ptree.
*/
#include <boost/property_tree/ptree_fwd.hpp>
#include <richio.h>
#include <dsnlexer.h>
typedef boost::property_tree::ptree PTREE;
typedef const PTREE CPTREE;
/**
* Function Scan
* fills an empty PTREE with information from a KiCad s-expresion stream. Use
* a DSNLEXER with an empty keyword table as @a aLexer. Useful for parsing
* s-expression files or strings of arbitrary grammars, say from a file or clipboard.
* The s-expression must be "KiCad compatible". See Documentation/s-expressions.txt
* for this KiCad compatible definition (it is the non-specctra mode).
* And also see in tools/property_tree.cpp for example usage.
*
* <code>
*
* FILE* fp = fopen( argv[1], "r" );
*
* static const KEYWORD empty_keywords[1] = {};
*
* DSNLEXER lexer( empty_keywords, 0, fp, wxString( FROM_UTF8( argv[1] ) ) );
*
* try
* {
* PTREE doc;
* Scan( &doc, &lexer );
* }
* catch( IO_ERROR ioe )
* {
* fprintf( stderr, "%s\n", TO_UTF8( ioe.errorText ) );
* }
*
* </code>
*/
void Scan( PTREE* aTree, DSNLEXER* aLexer ) throw ( IO_ERROR );
/**
* Function Format
* outputs a PTREE into s-expression format via an OUTPUTFORMATTER derivative.
*/
void Format( OUTPUTFORMATTER* out, int aNestLevel, int aCtl, CPTREE& aTree ) throw( IO_ERROR );
#endif // PTREE_H_