CLSS.ExtensionMethods.IDictionary.MoveKey

Problem

Changing the key of a key/value pair in any IDictionary collection is a 3-line process by default:

var value = dict[existingKey];
dict.Remove(existingKey);
dict[newKey] = value;

Checking for conflicting keys requires even more lines of code.

Solution

MoveKey does this in 1 line:

using CLSS;

dict.MoveKey(existingKey, newKey);

In case the source IDictionary contains an element with newKey, MoveKey will throw an exception and the key move will not proceed.

With an implicit type invocation, it returns an IDictionary<TKey, TValue>. With an explicit type invocation, it returns the original collection type.

using CLSS;

var customSortedNames = new Dictionary<int, string>()
{
  [1] = "Ryan",
  [2] = "David",
  [3] = "Wendell"
};
numbers.MoveKey(2, 5); // returns IDictionary<int, string>
numbers.MoveKey<Dictionary<int, string>, int, string>(1, 6); // returns Dictionary<int, string>;

This package also provides the TryMoveKey method. In the case of new key conflict, TryMoveKey will proceed, assign the conflicting value that was previously associated to newKey to the 3rd argument and return true. TryMoveKey returns false if there is no conflict.

using CLSS;

if (dict.TryMoveKey(existingKey, newKey, out var conflictingValue))
{ /* Do something with conflictingValue */ }

This package is a part of the C# Language Syntactic Sugar suite.