winix/confparser/confparser.cpp

/*
 * This file is a part of Winix
 * and is not publicly distributed
 * 
 * Copyright (c) 2008-2010, Tomasz Sowa
 * All rights reserved.
 * 
 */
 
#include "confparser.h"


ConfParser::ConfParser()
{
	separator  = '=';
	commentary = '#';
}


ConfParser::Status ConfParser::Parse(const char * file_name)
{
	line = 1;
	table.clear();

	file.clear();
	file.open( file_name );
	
	if( !file )
		return cant_open_file;
	
	ReadChar();
	status = ParseFile();
	
	file.close();
	
return status;
}



ConfParser::Status ConfParser::ParseFile()
{
	while( lastc != -1 )
	{
		if( ReadVariable() )
		{
			if( lastc != separator )
				return syntax_error;
		
			ReadChar(); // skipping separator
			
			if( !ReadValue() )
				return syntax_error;

			//table.insert( std::make_pair(variable, value) );
			table[variable] = value;
		}
		
		if( lastc == commentary )
			SkipLine();
		
		if( lastc != -1 && lastc != '\n' )
			return syntax_error;
		
		ReadChar(); // skipping '\n' if was
	}
	
return ok;	
}


bool ConfParser::IsVariableChar(int c)
{
	if( (c>='a' && c<='z') ||
	    (c>='A' && c<='Z') ||
	    (c>='0' && c<='9') ||
	    c=='.' || c==',' || c=='_' )

		return true;
	
return false;
}


bool ConfParser::IsValueSimpleChar(int c)
{
	//if( c==-1 || c=='\n' || IsWhite(c) || c==commentary )
	if( c==-1 || c=='\n' || c==commentary )
		return false;
	
return true;
}


bool ConfParser::ReadVariable()
{
	variable.clear();
	
	SkipWhite();
	
	while( IsVariableChar(lastc) )
	{
		variable += lastc;
		ReadChar();
	}

	SkipWhite();

return !variable.empty();
}



bool ConfParser::ReadValue()
{
	value.clear();
	
	SkipWhite();

	
	if( lastc == '"' )
		// quoted value
		return ReadValueQuoted();
	else
		return ReadValueSimple();
}




bool ConfParser::ReadValueQuoted()
{
	ReadChar(); // skipping the first quote
	
	while( lastc != '\n' && lastc != '"' && lastc != -1 )	
	{
		if( lastc == '\\' )
			ReadChar();
		
		value += lastc;	
		ReadChar();
	}
	
	if( lastc != '"' )
		return false;
		
	ReadChar(); // skipping the last quote
	
	SkipWhite();
	
return true;
}





bool ConfParser::ReadValueSimple()
{
	while( IsValueSimpleChar(lastc) )
	{
		value += lastc;
		ReadChar();
	}
	
	Trim(value);
	SkipWhite();
	
return true;	
}


int ConfParser::ReadChar()
{
	lastc = file.get();

	if( lastc == '\n' )
		++line;
	
return lastc;
}


bool ConfParser::IsWhite(int c)
{
	if( c==' ' || c=='\t' || c==13 || c==160 )
		return true;
		
return false;	
}



void ConfParser::SkipWhite()
{
	while( IsWhite(lastc) )
		ReadChar();
}



void ConfParser::SkipLine()
{
	while( lastc != -1 && lastc != '\n' )
		ReadChar();	
}



void ConfParser::Trim(std::string & s)
{
std::string::size_type i;
	
	if( s.empty() )
		return;
	
	// looking for white characters at the end
	for(i=s.size()-1 ; i>0 && IsWhite(s[i]) ; --i);
	
	if( i==0 && IsWhite(s[i]) )
	{
		// the whole string has white characters
		s.clear();
		return;
	}
	
	// deleting white characters at the end
	if( i != s.size() - 1 )
		s.erase(i+1, std::string::npos);
	
	// looking for white characters at the beginning
	for(i=0 ; i<s.size() && IsWhite(s[i]) ; ++i);
	
	// deleting white characters at the beginning
	if( i != 0 )
		s.erase(0, i);
}