/// <summary>
/// Determines whether two reference entities are semantically equivalent (whether they represent the same value).
/// </summary>
/// <param name="x">The first reference entity to compare.</param>
/// <param name="y">The second reference entity to compare.</param>
/// <returns>True when entities are semantically equivalent, false otherwise.</returns>
public bool Equals(IStonReferenceEntity x, IStonReferenceEntity y)
{
if (x == y)
{
return(true);
}
else if (x == null || y == null)
{
return(false);
}
IStonValuedEntity xval, yval;
xval = Document.GetReferencedValue(x);
yval = Document.GetReferencedValue(y);
if (xval == null || yval == null)
{
return(false);
}
else
{
return(Equals(xval, yval));
}
}
/// <summary>
/// Creates a structurally equivalent reference entity from a given entity.
/// </summary>
/// <param name="entity">The entity to copy the structure of.</param>
/// <returns>A structurally equivalent copy of the given entity.</returns>
public static IStonReferenceEntity Copy(IStonReferenceEntity entity)
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
return(new StonReferenceEntity(entity));
}
/// <summary>
/// Returns a hash code for a given reference entity, applied to entities semantic equivalence.
/// It is the same as its referenced value hash code.
/// </summary>
/// <param name="obj">The reference entity to get a hash code of.</param>
/// <returns>The hash code for the entity.</returns>
public int GetHashCode(IStonReferenceEntity obj)
{
if (obj == null)
{
return(0);
}
return(GetHashCode(Document.GetReferencedValue(obj)));
}
/// <summary>
/// Checks a validity of a given STON reference entity.
/// </summary>
/// <param name="entity">The entity to check the validity of.</param>
public static void ValidateEntity(IStonReferenceEntity entity)
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
try
{
if (entity.GlobalIdentifier != null)
{
ValidateGlobalIdentifier(entity.GlobalIdentifier);
}
if (entity.Address == null)
{
throw new StonException("A reference entity cannot have a non-existing address.");
}
ValidateAddress(entity.Address);
}
catch (StonException ex)
{
throw new StonReferenceException(entity, ex.Message);
}
}
/// <summary>
/// Creates a structurally equivalent reference entity from a given entity.
/// </summary>
/// <param name="entity">The entity to copy the structure of.</param>
public StonReferenceEntity(IStonReferenceEntity entity)
: this(entity.Address, entity.GlobalIdentifier)
{
}
// writes a reference entity
private void WriteEntity(StonTokenWriter writer, IStonReferenceEntity entity)
{
WriteGlobalIdentifier(writer, entity.GlobalIdentifier);
WriteReferenceAddress(writer, entity.Address);
}