/// <summary>
/// Merges two instances based on the stronger of both variabilities and the set union of their reaching definitions
/// </summary>
/// <param name="a">first instance</param>
/// <param name="b">second instance</param>
/// <returns>instance representing the merged information of both instances</returns>
public static VariabilityInfo MergeDefs(VariabilityInfo a, VariabilityInfo b)
{
Contract.Requires(a.Definitions != null);
Contract.Requires(b.Definitions != null);
return(new VariabilityInfo(
VariabilityOperations.Stronger(a.Variability, b.Variability),
a.Definitions.Union(b.Definitions).Distinct().ToArray()));
}
/// <summary>
/// Two instances are defined to be equal iff they have the same variability and the same set of reaching definitions.
/// </summary>
/// <param name="obj">some object, possibly an instance of VariabilityInfo</param>
/// <returns>whether both instances meet the equality criterion</returns>
public override bool Equals(object obj)
{
VariabilityInfo vi = obj as VariabilityInfo;
if (vi == null)
{
return(false);
}
return(Variability == vi.Variability &&
Definitions.SequenceEqual(vi.Definitions));
}
/// <summary>
/// Merges two instances under assumption of a single reaching definition
/// </summary>
/// <param name="a">first instance</param>
/// <param name="b">second instance</param>
/// <param name="def">the one and only reaching definition</param>
/// <returns>merged instance, based on the stronger of both variabilities</returns>
public static VariabilityInfo MergeByNewDef(VariabilityInfo a, VariabilityInfo b, int def)
{
return(CreateBySingleDef(
VariabilityOperations.Stronger(a.Variability, b.Variability),
def));
}
