/// <summary>
/// Computes the filter that includes only leaf filters that satisfy the given predicate.
/// The result is guaranteed to be less than or equal in restrictiveness to the original.
/// This means that it will never filter out results that the original filter would not have
/// filtered.
/// </summary>
/// <param name="node"></param>
/// <param name="predicate"></param>
/// <returns></returns>
public static IFilterNode <TFilter> GetPartial <TFilter>(this IFilterNode <TFilter> node, Func <TFilter, bool> predicate)
where TFilter : IFilter
=> node.Relax(
filter =>
{
if (predicate(filter))
{
return(filter.ToLeafFilterNode());
}
return(FilterNode <TFilter> .True);
},
filter =>
{
if (predicate(filter))
{
return(filter.ToLeafFilterNode());
}
return(FilterNode <TFilter> .False);
});
