/// <summary>
/// Determine the complete list of types reachable as a consequence of a starting group of types.
/// </summary>
/// <remarks>
/// Provide a single shared implementation that is used either at type-level checks, as well as in diagnostic checks to ensure fidelity of result.
/// </remarks>
/// <param name="initialTypes">The types to start searching from.</param>
/// <param name="ancestorsOnlyOnFirst"></param>
/// <param name="getTargets">
/// False to follow relationships in reverse to potential sources of grants.
/// True to follow relationships in forward to target types that receive grants.
/// </param>
/// <returns></returns>
public static IEnumerable <WalkStep <Tuple <Relationship, Direction, EntityType, EntityType> > > ReachableTypes(IEnumerable <EntityType> initialTypes)
{
var entityComparer = new EntityIdEqualityComparer <EntityType>( );
var tupleComparer = new CastingComparer <Tuple <Relationship, Direction, EntityType, EntityType>, EntityType>(t => t.Item3, entityComparer);
return(Delegates.WalkGraphWithSteps(
initialTypes.Select(et => new Tuple <Relationship, Direction, EntityType, EntityType>(null, Direction.Forward, et, null)),
tuple =>
{
EntityType et = tuple.Item3;
var securingRelationships = GetSecuredRelationships(et, false, false); // hmm .. this should probably pass true
return securingRelationships; // Item3 = the next entityType
},
tupleComparer
));
}
/// <summary>Try get a custom comparer for <paramref name="type"/></summary>
/// <param name="type">The type.</param>
/// <param name="comparer">The comparer.</param>
/// <returns>True if a custom comparer is provided for <paramref name="type"/></returns>
public bool TryGetComparer(Type type, out CastingComparer comparer)
{
comparer = null;
return this.comparers?.TryGetValue(type, out comparer) == true;
}
