/// <summary>
/// Combine the specified filter expressions.
/// </summary>
/// <param name="first">First.</param>
/// <param name="second">Second.</param>
public static FilterExpression Combine(FilterExpression first, FilterExpression second)
{
if (first == null)
return second;
if (second == null)
return first;
if (first.Result != second.Result)
throw new ArgumentException("Both filters must have the same result property");
return new FilterExpression(first.m_filters.Union(second.m_filters).Select(x => x.Type == FilterType.Regexp ? ("[" + x.Filter + "]") : x.Filter), first.Result);
}