If you want better concurrency than full synchronization, there is one way I know of to do it, using a ConcurrentHashMap as the backing map. The following is a sketch only. public final class ConcurrentHashSet<E> extends ForwardingSet<E> implements Set<E>, Queue<E> { private enum Dummy { VALUE } private final ConcurrentMap<E, Dummy> map; ConcurrentHashSet(ConcurrentMap<E, Dummy> map) … Read more
Why is this interface used? Because it supports the basic operations that would allow a client programmer to iterate over any kind of collection (note: not necessarily a Collection in the Object sense). Why are the methods… not directly coded to the data structure implementation itself? They are, they’re just marked Private so you can’t … Read more
Could you not just use the same query client-side when you want to look at the items? In a lib directory: enabledItems = function() { return Items.find({enabled: true}); } processedItems = function() { return Items.find({processed: true}); } On the server: Meteor.publish(‘enabled_items’, function() { return enabledItems(); }); Meteor.publish(‘processed_items’, function() { return processedItems(); }); On the client … Read more
It seems that the INotifyCollectionChanged interface allows for updating when multiple items were added, so I’m not sure why ObservableCollection<T> doesn’t have an AddRange. You could make an extension method for AddRange, but that would cause an event for every item that is added. If that isn’t acceptable you should be able to inherit from … Read more
Why? Because if you force iterator to have a reset method every iterator has to have a reset method. That gives every iterator writer extra work. Plus some iterators are really hard (or really expensive) to reset, and you wouldn’t want users to call reset on them. Iterators over files or streams are good examples. … Read more
Many “obvious” features are missing from the JDK and its various APIs. Why this particular feature was omitted / forgotten? We can only guess. But your question has been a RFE at Sun/Oracle for a long time: https://bugs.java.com/bugdatabase/view_bug?bug_id=6278287 http://www.java.net/node/644910 You could support those RFEs by commenting on them. Note, here’s an authoritative answer by Joshua … Read more
“Random access O(1)” is an extremely exacting requirement which basically imposes an underlying hash table — and I hope you do mean random READS only, because I think it can be mathematically proven than it’s impossible in the general case to have O(1) writes as well as O(N) ordered iteration. I don’t think you will … Read more
Using breakOut Use breakOut as the CanBuildFrom and let the typer know what you want your result type to be (unfortunately you need to specify String here) scala> import collection.breakOut import collection.breakOut scala> List(1, 2, 3) res0: List[Int] = List(1, 2, 3) scala> res0.map(_.toString)(breakOut) : Vector[String] res2: Vector[String] = Vector(1, 2, 3) Using to[Collection] (starting … Read more
Consider what you’re doing here by using filters in the controller to affect how a model behaves when saved or updated. I think a much cleaner method would be a before_save call back in the model or an observer. This way, you’re getting the same behavior no matter where the change originates from, whether its … Read more
It would be as easy as casting the whole dictionary reference to IReadOnlyDictionary<string, IReadOnlyList<string>> because Dictionary<TKey, TValue> implements IReadOnlyDictionary<TKey, TValue>. BTW, you can’t do that because you want the List<string> values as IReadOnlyList<string>. So you need something like this: var readOnlyDict = (IReadOnlyDictionary<string, IReadOnlyList<string>>)dict .ToDictionary(pair => pair.Key, pair => pair.Value.AsReadOnly()); Immutable dictionaries This is just … Read more