IndexedLinq enhances IP.i4o (index for objects) (https://github.com/ipashchuk/IP.i4o) wich enhances the i4o library (https://github.com/ericksoa/i4o) from which it was forked. This library was renamed as well in order to prevent confusion if, for example, both this and the original were to appear on NuGet.

• [https://github.com/dotnetprojects/IndexedLinq] (https://github.com/dotnetprojects/IndexedLinq)

• Allows indexes to be added to collections to optimize LINQ queries since, by default, LINQ queries collection items sequentially. Specifically, this is achieved by adding either a comparison or an equality index, which have O(log n) or O(1) operation, respectively.

Standard (unoptimized) LINQ queries: **O(n)**
LINQ queries with comparison index: **O(log n)**
LINQ queries with equality index: **O(1)**

• Optimized inefficient index queries whereby the binary search was performed twice: first to check if the key existed and again to look up the key/value
• Removed c5 collections dependency/source code (it was used by i40 primarily for its red-black tree implementation and helper methods for selecting ranges) in favor of the .NET built-in generic SortedList<TKey,TValue> (the range selection functionality was implemented via SortedList<TKey,TValue> extension methods).
• Removed Silverlight projects -- this is mainly because I'm not developing anything for Silverlight at the moment and do not want to spend time maintaining it.

• Net Standard 2.0 support

• github.com/ipashchuk/IP.i4o/wiki

• [https://github.com/dotnetprojects/IndexedLinq/issues] (https://github.com/dotnetprojects/IndexedLinq/issues)

• NuGet [https://www.nuget.org/packages/DotNetProjects.IndexedLinq/] (https://www.nuget.org/packages/DotNetProjects.IndexedLinq/)
• Download/fork the source and build.

GNU Lesser General Public License (LGPL), Version 2.1