KTrie 2.5.0

dotnet add package KTrie --version 2.5.0                
NuGet\Install-Package KTrie -Version 2.5.0                
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="KTrie" Version="2.5.0" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add KTrie --version 2.5.0                
#r "nuget: KTrie, 2.5.0"                
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install KTrie as a Cake Addin
#addin nuget:?package=KTrie&version=2.5.0

// Install KTrie as a Cake Tool
#tool nuget:?package=KTrie&version=2.5.0                


Trie (a.k.a. prefix tree) is an ordered tree data structure that is used to store an associative array where the keys are usually strings. All the descendants of a node have a common prefix of the string associated with that node, and the root is associated with the empty string.
Reference: Wikipedia

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  • Looking up keys is faster. Looking up a key of length key takes O(|key|) time
  • Looking up prefixes is faster. Looking up a prefix takes O(|prefix|) time
  • Removing takes O(|key|) time
Trie trie = ["star", "start", "stack", "stop", "stay", "key"];

           s  k
          /    \
         t      e
        / \      \
      a    o     [y]
    / | \    \
  [r][y] c   [p]
  /       \
[t]       [k]

where [char] -- is end of word

The library provides two implementations of the trie data structure:

  • Trie : ICollection<string>, this is a set which stores unique strings
  • TrieDictionary<TValue> : IDictionary<string, TValue>, this is a key-value-pair collection


TrieDictionary initialization:

// Initialization
TrieDictionary<int> trie = [];

// or using constructor with comparer
IEqualityComparer<char> comparer = ...; // specify the comparer
TrieDictionary<int> trieWithComparer = new(comparer);

Adding items to trie

trie.Add("key", 17);

The Add method throws ArgumentNullException if a value with the specified key already exists, however setting the Item property overwrites the old value. In other words, TrieDictionary<TValue> has the same behavior as Dictionary<TKey, TValue>.

The main advantage of trie is really fast prefix lookup. To find all items of TrieDictionary<TValue> which have keys with given prefix use StartsWith method which returns IEnumerable<KeyValuePair<string, TValue>>:

var result = trie.StartsWith("abc");

Another handy method is Matches(IReadOnlyList<Character> pattern)

var result = trie.Matches([Character.Any, 'c', Character.Any, Character.Any, 't']);

which will return all words that match this regex: ^.c.{2}t$, e.g.: octet, scout, scoot.

There are two overloads of the StartsWith method:

  • StartsWith(string value)
  • StartsWith(IReadOnlyList<Character> pattern)

Benchmark tests

For performance tests I used 370105 English words (from: https://github.com/dwyl/english-words).

Method Mean Error StdDev Allocated
Load_Trie 211,557.48 us 1,981.525 us 1,756.570 us 72741.27 KB
Load_DictionaryWithAllPrefixes 577,935.48 us 6,096.177 us 5,090.583 us 317389.57 KB
Trie_StartsWith 11,420.52 us 78.619 us 69.693 us 3604.64 KB
Linq_StartsWith 117,671.68 us 1,777.550 us 1,662.722 us 2843.55 KB
Linq_GroupedByFirstLetter_StartsWith 10,544.61 us 206.705 us 339.622 us 2844.41 KB
Linq_DictionaryWithAllPrefixes 3,593.91 us 69.920 us 80.520 us 2840.66 KB
Trie_Matches 15.13 us 0.298 us 0.446 us 18.05 KB
Trie_PatternStartsWith 66.07 us 1.306 us 1.504 us 65.65 KB
String_PatternMatching 887.43 us 13.962 us 12.377 us 1.56 KB
String_PrefixPatternMatching 911.10 us 14.261 us 13.340 us 33.72 KB
Regex_PatternMatching 27,146.03 us 232.150 us 217.153 us 1.57 KB
Regex_PrefixPatternMatching 27,414.88 us 265.306 us 248.168 us 33.73 KB

© Kirill Polishchuk

Product Compatible and additional computed target framework versions.
.NET net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • net8.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories (1)

Showing the top 1 popular GitHub repositories that depend on KTrie:

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Integrated development environment (IDE), an editor for Smart Scripts (SAI/smart_scripts) for TrinityCore based servers. Cmangos support work in progress. Featuring a 3D view built with OpenGL and custom ECS framework
Version Downloads Last updated
2.5.0 788 4/29/2024
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