RockHouse.Collections

RockHouse.Collections is a Collection class package that mimics the Java language API and the Apache.Commons.CollectionsAPI. It also adds several proprietary APIs.

The following is an example of a class.

• CollectionUtils
• DictionaryUtils
• EnumerableUtils
• ListUtils
• SetUtils
• Dictionaries.HashMap
• Dictionaries.LinkedHashMap
• Dictionaries.LinkedOrderedDictionary
• Dictionaries.ListOrderedDictionary
• Dictionaries.LruMap/Dictionary
• Dictionaries.ReferenceDictionary
• Dictionaries.WeakHashMap
• Dictionaries.Multi.HashSetValuedDictionary
• Dictionaries.Multi.ListValuedMap/Dictionary
• Sets.LinkedHashSet
• Sets.LinkedOrderedSet
• Sets.ListOrderedSet

etc

Java language-like

var map = new HashMap<string, string>();

if (map.IsEmpty)
{
    Console.WriteLine("empty");
}

var get1 = map.Get("a"); // get1 is null

var put1 = map.Put("a", "1"); // put1 is null
var get2 = map.Get("a"); // get2 is 1

var put2 = map.Put("a", "2"); // put2 is 1
var get3 = map.Get("a"); // get3 is 2

Note: There are some incompatibilities with Java. Since null is not allowed in primitive types, the API that returns null substitutes default(V). For example, default(int) is 0.

Utilities similar to functions in common scripting languages such as Perl, Ruby, Python, etc.

var list = new List<int>();
ListUtils.Push(list, 1, 2);
var tail = ListUtils.Pop(list); // tail is 2
ListUtils.Unshift(list, 0);
var head = ListUtils.Shift(list); // head is 0

Compatibility with .NET API

Collection initializer

var map = new HashMap<string, int>()
{
    { "a", 1 },
    { "b", 2 },
    { "c", 3 },
};

Indexer

map["key"] = 10;
var value = map["key"]; // value is 10
var abort = map["not found"]; // KeyNotFoundException

Enumerable

foreach (var entry in map)
{
    Console.WriteLine($"key={entry.Key}, value={entry.Value}");
}

LINQ

var filteredList = map.Where(e => e.Value > 1)
                        .Select(e => e.Key)
                        .ToList();

Json

With System.Text.Json

var json = JsonSerializer.Serialize(map);
var restore = JsonSerializer.Deserialize<HashMap<string, int>>(json);

License

This code is under the Apache License, Version 2.0.