/// <summary>
/// Determines if a common super type (LUB) exists between type1 and type2.
/// </summary>
/// <param name="type1"></param>
/// <param name="type2"></param>
/// <param name="commonType"></param>
/// <returns>
/// true if a common super type between type1 and type2 exists and out commonType represents the common super type.
/// false otherwise along with commonType as null
/// </returns>
internal static bool TryGetCommonType(TypeUsage type1, TypeUsage type2, out TypeUsage commonType)
{
Debug.Assert(type1 != null, "type1 must not be NULL");
Debug.Assert(type2 != null, "type2 must not be NULL");
commonType = null;
if (type1.EdmEquals(type2))
{
commonType = ForgetConstraints(type2);
return(true);
}
if (Helper.IsPrimitiveType(type1.EdmType) && Helper.IsPrimitiveType(type2.EdmType))
{
return(TryGetCommonPrimitiveType(type1, type2, out commonType));
}
EdmType commonEdmType;
if (TryGetCommonType(type1.EdmType, type2.EdmType, out commonEdmType))
{
commonType = ForgetConstraints(TypeUsage.Create(commonEdmType));
return(true);
}
commonType = null;
return(false);
}
/// <summary>
/// Get the "new" type corresponding to the input type. For structured types,
/// we return the flattened record type.
/// For collections of structured type, we return a new collection type of the corresponding flattened
/// type.
/// For enum types we return the underlying type of the enum type.
/// For strong spatial types we return the union type that includes the strong spatial type.
/// For everything else, we return the input type
/// </summary>
/// <param name="type">the original type</param>
/// <returns>the new type (if any)</returns>
private md.TypeUsage GetNewType(md.TypeUsage type)
{
if (TypeUtils.IsStructuredType(type))
{
TypeInfo typeInfo = GetTypeInfo(type);
return(typeInfo.FlattenedTypeUsage);
}
md.TypeUsage elementType;
if (TypeHelpers.TryGetCollectionElementType(type, out elementType))
{
md.TypeUsage newElementType = GetNewType(elementType);
if (newElementType.EdmEquals(elementType))
{
return(type);
}
else
{
return(TypeHelpers.CreateCollectionTypeUsage(newElementType));
}
}
if (TypeUtils.IsEnumerationType(type))
{
return(TypeHelpers.CreateEnumUnderlyingTypeUsage(type));
}
if (md.TypeSemantics.IsStrongSpatialType(type))
{
return(TypeHelpers.CreateSpatialUnionTypeUsage(type));
}
// simple scalar
return(type);
}
/// <summary>
/// determines if subType is equal to or a sub-type of superType.
/// </summary>
/// <param name="subType"></param>
/// <param name="superType"></param>
/// <returns>true if subType is equal to or a sub-type of superType, false otherwise</returns>
internal static bool IsSubTypeOf(TypeUsage subType, TypeUsage superType)
{
Debug.Assert(subType != null, "subType must not be NULL");
Debug.Assert(superType != null, "superType must not be NULL");
if (subType.EdmEquals(superType))
{
return(true);
}
if (Helper.IsPrimitiveType(subType.EdmType) && Helper.IsPrimitiveType(superType.EdmType))
{
return(IsPrimitiveTypeSubTypeOf(subType, superType));
}
return(subType.IsSubtypeOf(superType));
}