internal virtual T Or(T other)
{
if (!this.CanOr(other))
{
return(default(T));
}
// start with a deep copy of this
T result = this.Clone();
// Or will only affect the collection properties since CanOr requires the non-collection properties to have equivalent values
foreach (Tuple <PropertyInfo, ExpressionElementCollectionPropertyAttribute> tuple in this.ExpressionElementCollectionProperties)
{
// Get property and attribute
PropertyInfo property = tuple.Item1;
ExpressionElementCollectionPropertyAttribute attribute = tuple.Item2;
// Get the value of the collection
object thisVal = property.GetValue(result, null);
// CanOr ensures that the collections are either both null or neither null so only one needs to be tested
if (thisVal != null)
{
object otherVal = property.GetValue(other, null);
// Find Union function and invoke to get the union
object union = attribute.InvokeUnionMethod(new[] { thisVal, otherVal });
// set the union value on the copy (result)
property.SetValue(result, union, null);
}
}
return(result);
}
internal virtual T And(T other)
{
// start with a deep copy both elements
T result = this.Clone();
other = other.Clone();
// for AND, the non-collection properties cannot conflict
foreach (PropertyInfo property in this.ExpressionElementProperties)
{
// Get values
var thisVal = property.GetValue(result, null);
var otherVal = property.GetValue(other, null);
// if other has a constraint
if (otherVal != null)
{
// AND this has a constraint
if (thisVal != null)
{
// then they must be the same
if (!object.Equals(thisVal, otherVal))
{
return(default(T));
}
}
else
{
// other has one, but this doesn't simply add the constraint
property.SetValue(result, otherVal, null);
}
}
}
// for the collection properties, the result will have the intersection
foreach (Tuple <PropertyInfo, ExpressionElementCollectionPropertyAttribute> tuple in this.ExpressionElementCollectionProperties)
{
// Get property and attribute
PropertyInfo property = tuple.Item1;
ExpressionElementCollectionPropertyAttribute attribute = tuple.Item2;
// Get values
var thisVal = property.GetValue(result, null);
var otherVal = property.GetValue(other, null);
// if other has a constraint
if (otherVal != null)
{
// Take other's constraint in the absence of one on this, otherwise take the intersection
if (thisVal == null)
{
property.SetValue(result, otherVal, null);
}
else
{
// Find Intersect function and invoke to get the intersection
object intersect = attribute.InvokeIntersectMethod(new[] { thisVal, otherVal });
property.SetValue(result, intersect, null);
}
}
}
return(result);
}
