External Operator Demo Sample Code

void CallbackDemo( void )
{
	char		theExpression[ 128 ];
	long		expLength;
	bool		keepLooping = true;

	LZObjectHandle	hCurrentContext = 0;
	bool		bSetContextResult = false;
	long		lDefineOpResult = 0;
	
	bool		bIsSymbol = false;
	bool		bIsOp = false;
	bool		bIsVar = false;

	lzCreatePublicContext( "CallbackDemo" );
	hCurrentContext = lzSetContext( "CallbackDemo", false );

	if ( !hCurrentContext )
	{
		cout << "Failed to set Elzed context.\r\n";
		cout << lzGetLastErrorText() << "\r\n\n";
	}

	lDefineOpResult = lzLinkCallbackOp(	kGlobalScope,					// scope
						"xfunc",					// operator name
						"prefix",					// operator type
						"boolean",					// return type
						"number first, string second, boolean third",	// parm list
						"/",						// precedence matching operator
						MyExternalFunction );				// function pointer

	lDefineOpResult = lzLinkCallbackOp(	kGlobalScope,					// scope
						"yfunc",					// operator name
						"prefix",					// operator type
						"number",					// return type
						"number first, number second",			// variable parm list
						"^",						// precedence matching operator
						MyOtherExternalFunction );			// function pointer

	lDefineOpResult = lzDefineExpOp(	kGlobalScope,					// scope
						"zfunc",					// operator name
						"prefix",					// operator type
						"number",					// return type
						"number first, number second",			// parm list
						"/",						// precedence matching operator
						"first^second" );				// expression

	if ( lDefineOpResult )
	{
		cout << "Failed to load external operator.\r\n";
		cout << lzGetLastErrorText() << "\r\n\n";
	}

	bIsSymbol = lzIsSymbol( kAnyScope, "+" );

	bIsSymbol = lzIsSymbol( kCosmicScope, "zfunc" );
	bIsSymbol = lzIsSymbol( kGlobalScope, "zfunc" );
	bIsSymbol = lzIsSymbol( kAnyScope, "zfunc" );

	bIsOp = lzIsOp( kCosmicScope, "zfunc" );
	bIsOp = lzIsOp( kGlobalScope, "zfunc" );
	bIsOp = lzIsOp( kAnyScope, "zfunc" );

	bIsVar = lzIsVar( kAnyScope, "sauron" );

	while ( keepLooping )
	{
		GetInputString( theExpression, 128 );

		expLength = strlen( theExpression );
		
		if ( expLength == 0 )
			keepLooping = false;

		else if ( (expLength == 1) && (theExpression[ 0 ] == '\r') )
			keepLooping = false;
			
		else if (theExpression[ 0 ] == '\\')
			keepLooping = false;

		else
		{
			cout << "  " << lzEvalExpStrToStr( theExpression ) << '\n';
			
			if ( lzGetLastErrorID() )
				cout << lzGetLastErrorText() << '\n';
				
			cout.flush();
		}
	}

	bSetContextResult = lzDestroyPublicContext( "CallbackDemo" );
}