private static UnaryComparison compExprToUnaryComp(ComparisonExpression expr)
{
if (!expr.isUnary())
{
return(null);
}
if (expr.arithmetic_operand1.isConstant())
{
LinearIntegerExpression tmp = expr.arithmetic_operand1;
expr.arithmetic_operand1 = expr.arithmetic_operand2;
expr.arithmetic_operand2 = tmp;
switch (expr.comparison_operator)
{
case ComparisonExpression.ComparisonOperator.GEQ:
expr.comparison_operator = ComparisonExpression.ComparisonOperator.LEQ;
break;
case ComparisonExpression.ComparisonOperator.GT:
expr.comparison_operator = ComparisonExpression.ComparisonOperator.LT;
break;
case ComparisonExpression.ComparisonOperator.LEQ:
expr.comparison_operator = ComparisonExpression.ComparisonOperator.GEQ;
break;
case ComparisonExpression.ComparisonOperator.LT:
expr.comparison_operator = ComparisonExpression.ComparisonOperator.GT;
break;
default:
break;
}
}
VariableType variable = expr.GetVariables().First();
int coefficient = expr.arithmetic_operand1.coefficients[variable];
int constant = expr.arithmetic_operand2.constant;
double divided = (double)constant / (double)coefficient;
switch (expr.comparison_operator)
{
case ComparisonExpression.ComparisonOperator.EQ:
case ComparisonExpression.ComparisonOperator.NEQ:
if (!isInt(divided))
{
return(null);
}
else
{
expr.arithmetic_operand2 = LinearIntegerExpression.Constant(Convert.ToInt32(divided));
}
break;
case ComparisonExpression.ComparisonOperator.GEQ:
expr.arithmetic_operand2 = LinearIntegerExpression.Constant(Convert.ToInt32(Math.Ceiling(divided)));
break;
case ComparisonExpression.ComparisonOperator.GT:
expr.arithmetic_operand2 = LinearIntegerExpression.Constant(Convert.ToInt32(Math.Floor(divided)));
break;
case ComparisonExpression.ComparisonOperator.LEQ:
expr.arithmetic_operand2 = LinearIntegerExpression.Constant(Convert.ToInt32(Math.Floor(divided)));
break;
case ComparisonExpression.ComparisonOperator.LT:
expr.arithmetic_operand2 = LinearIntegerExpression.Constant(Convert.ToInt32(Math.Ceiling(divided)));
break;
default:
throw new ArgumentException();
}
if (expr.comparison_operator == ComparisonExpression.ComparisonOperator.GEQ)
{
expr.comparison_operator = ComparisonExpression.ComparisonOperator.GT;
expr.arithmetic_operand2.constant--;
}
if (expr.comparison_operator == ComparisonExpression.ComparisonOperator.LEQ)
{
expr.comparison_operator = ComparisonExpression.ComparisonOperator.LT;
expr.arithmetic_operand2.constant++;
}
switch (expr.comparison_operator)
{
case ComparisonExpression.ComparisonOperator.EQ:
return(UnaryComparison.equal(variable, expr.arithmetic_operand2.constant));
case ComparisonExpression.ComparisonOperator.GT:
return(UnaryComparison.greater(variable, expr.arithmetic_operand2.constant, new HashSet <int>()));
case ComparisonExpression.ComparisonOperator.LT:
return(UnaryComparison.between(variable, -1, expr.arithmetic_operand2.constant, new HashSet <int>()));
default:
return(null);
}
}