public static IFilter Join(IFilter first, IFilter second)
{
if (first == null && second == null)
{
return(null);
}
else if (first == null)
{
return(second);
}
else if (second == null)
{
return(first);
}
else if (first.Empty)
{
return(second);
}
else if (second.Empty)
{
return(first);
}
else
{
if (first is FilterExpression && second is FilterExpression && ((FilterExpression)first).Result == ((FilterExpression)second).Result)
{
return(FilterExpression.Combine((FilterExpression)first, (FilterExpression)second));
}
return(new JoinedFilterExpression(first, second));
}
}
public static IFilter Join(IFilter first, IFilter second)
{
if (first == null && second == null)
return null;
else if (first == null)
return second;
else if (second == null)
return first;
else if (first.Empty)
return second;
else if (second.Empty)
return first;
else
{
if (first is FilterExpression && second is FilterExpression && ((FilterExpression)first).Result == ((FilterExpression)second).Result)
return FilterExpression.Combine((FilterExpression)first, (FilterExpression)second);
return new JoinedFilterExpression(first, second);
}
}