Tiktoken

This implementation aims for maximum performance, especially in the token count operation.
There's also a benchmark console app here for easy tracking of this.
We will be happy to accept any PR.

Implemented encodings

• cl100k_base
• r50k_base
• p50k_base
• p50k_edit

Usage

var encoding = Tiktoken.Encoding.ForModel("gpt-4");
var tokens = encoding.Encode("hello world"); // [15339, 1917]
var text = encoding.Decode(tokens); // hello world
var numberOfTokens = encoding.CountTokens(text); // 2

var encoding = Tiktoken.Encoding.Get("p50k_base");
var tokens = encoding.Encode("hello world"); // [31373, 995]
var text = encoding.Decode(tokens); // hello world

Benchmarks

You can view the reports for each version here

BenchmarkDotNet=v0.13.5, OS=macOS Ventura 13.3.1 (a) (22E772610a) [Darwin 22.4.0]
Apple M1 Pro, 1 CPU, 10 logical and 10 physical cores
.NET SDK=7.0.203
  [Host]     : .NET 7.0.5 (7.0.523.17405), Arm64 RyuJIT AdvSIMD
  Job-MEZVRD : .NET 7.0.5 (7.0.523.17405), Arm64 RyuJIT AdvSIMD DEBUG

BuildConfiguration=Debug  

Possible optimizations

• Modes - Fast(without special token regex)/Strict
• SIMD?
• Parallelism?
• string as dictionary key?

Support

Priority place for bugs: https://github.com/tryAGI/LangChain/issues
Priority place for ideas and general questions: https://github.com/tryAGI/LangChain/discussions
Discord: https://discord.gg/Ca2xhfBf3v