An extensible math expression parser with plug-ins

#include "TestCases.h"
#include "MTParser.h"
#include <windows.h>
#include "MTParserExcepStrEng.h"


MTSTRING MTTestCases::longToS(long val)
{
	MTCHAR str[20];
	return MTLTOSTR(val, str, 10);

}

bool MTTestCases::test()
{
	
	addTest(_T("1+2"), 3, true);
	addTest(_T("1-2"), -1, true);
	addTest(_T("1--2"), 3, true);	

	addTest(_T("2*3"), 6, true);	
	addTest(_T("4/2"), 2, true);	
	addTest(_T("2^3"), 8, true);	
	addTest(_T("10%3"), 1, true);	
	addTest(_T("avg(1,1-1+2,3,(2+2))"), 2.5, true);	
	addTest(_T("sum(1,2,3,2^2)"), 10, true);	
	addTest(_T("rand()*0"), 0, true);		// function with no argument	
	addTest(_T("min(1,2,3)"), 1, true);		// overloaded function	
	
	addTest(_T("x+y+sin(0)/2^3-40.9*2"), -81.8, true);	

	addTest(_T("min(sin(x),2)"), 0, true);
	addTest(_T("max(100.98,101)"), 101, true);

	addTest(_T("min(sin([x+1]),2)"), 0, true);	// begin-end variable name delimiters
	addTest(_T("[min](1,0)"), 0, false);		// min is not a variable name
	

	addTest(_T("min(sin(ali),2)"), 0, false);	// undefined variable "ali"
	addTest(_T("foo(sin(x),2)"), 0, false);		// undefined function "foo"

	// unary minus op
	addTest(_T("-1"),-1, true);			
	addTest(_T("--1"), 1, true);			
	addTest(_T("---1"), -1, true);	
	addTest(_T("-(1)"), -1, true);	
	addTest(_T("-(1+2)"), -3, true);	
	addTest(_T("--(1)"), 1, true);	
	addTest(_T("1+-2"), -1, true);	
	addTest(_T("1+-(((1+2)))"), -2, true);	
	

	// brackets
	addTest(_T("-(1)+3"), 2, true);	
	addTest(_T("(2+3"), 2, false);		// missing closing bracket
	addTest(_T("(2+3-(3/2)"), 2, false);		// missing closing bracket
	addTest(_T("3/2)"), 2, false);		// missing opening bracket
	addTest(_T("(1)-2"), -1, true);	
	addTest(_T("sin(((1-1)))"), 0, true);	// tricky inside brackets
	addTest(_T("-(((-2)))+3"), 5, true);	
	addTest(_T("avg((2),4)"), 3, true);	

	// argument separator
	addTest(_T("avg(2,,2)"), 0, false);		// useless ","
	addTest(_T("avg(2,2,)"), 0, false);		// useless "," at the end	
	addTest(_T("avg(,2,2)"), 0, false);		// useless "," at the beginning	
	
	// bad syntax	
	addTest(_T("sin(1,2)"), 0, false);		// too many arguments
	addTest(_T("sin()"), 0, false);			// not enough argument
	addTest(_T("1+2/4+"), 0, false);		// expression cannot end with an operator
	addTest(_T("sin(+))"), 0, false);		// missing + arguments
	addTest(_T("sin(-)"), 0, false);		// missing - arguments
	addTest(_T("(2+3)2"), 0, false);		// the * operator is not implicit
	addTest(_T("5.1.2+3"), 0, false);		// 5.1.2 is not a valid number

	return runTest();
}


void MTTestCases::addTest(MTSTRING expr, MTDOUBLE result, bool valid)
{
	TESTCASE tc;
	tc.expr = expr;
	tc.expectedResult = result;
	tc.valid = valid;

	m_testCases.push_back(tc);

}

bool MTTestCases::runTest()
{
	MTParser parser;

	int nbTests = m_testCases.size();
	bool success = true;
	MTDOUBLE x,y;
	x=0;
	y=0;

	try
	{
		parser.defineVar(_T("x"), &x);
		parser.defineVar(_T("x+1"), &x);	// variable name with operator character: use begin-end delimiters
		parser.defineVar(_T("y"), &y);
	}
	catch( MTException &e )
	{
		MTSTRING msg = _T("Unit test definition error: ");
		msg += e.m_description;
		
		msg += _T("\n\r");

		OutputDebugString(msg.c_str());
		return false;
	}


	int t;
	for( t=0; t<nbTests; t++ )
	{
		try
		{
			MTDOUBLE val = parser.evaluate(m_testCases[t].expr.c_str());

			if(!m_testCases[t].valid )
			{
				MTSTRING msg = _T("Test failed #");
				msg += longToS(t);
				msg += _T(", ");
				msg += m_testCases[t].expr;
				msg += _T(".  Reason->expected failed");	
				msg += _T("\n\r");
				
				OutputDebugString(msg.c_str());
				success = false;

			}	  

			
			if( val != m_testCases[t].expectedResult )
			{
				MTSTRING msg = _T("Test failed #");
				msg += longToS(t);
				msg += _T(", ");
				msg += m_testCases[t].expr;
				
				msg += _T(".  Reason->bad result");		
				msg += _T("\n\r");

				OutputDebugString(msg.c_str());
				success = false;
			}
			

		}
		catch( MTException &e)
		{
			if( m_testCases[t].valid )
			{
				MTSTRING msg = _T("Test failed #");
				msg += longToS(t);
				msg += _T(", ");
				msg += m_testCases[t].expr;
				
				msg += _T(".  Reason-> ");
				msg += e.m_description;
				msg += _T("\n\r");

				OutputDebugString(msg.c_str());
				success = false;
			}

		}
	}

	return success;

}