DesignPatterns

Lightweight runtime primitives + Roslyn source generators for .NET design patterns.

Mark implementations with attributes; the generators emit keys, registries, and pipelines, and analyzers catch misuse at compile time. Overlap with libraries such as MediatR, Polly, or Stateless is fine — this project explores compile-time glue around small primitives, not a one-framework-to-rule-them-all product.

Early preview. Public APIs, generated code shapes, and DP### diagnostics are not stable yet. Pin a package version (or a Git commit) until a stability announcement.

Install

<PackageReference Include="Skymly.DesignPatterns" Version="0.2.4-preview1" />

dotnet add package Skymly.DesignPatterns --version 0.2.4-preview1

C# namespaces remain DesignPatterns.*. Full guides: Getting started · 中文文档

Quick example

using DesignPatterns.Behavioral;

public interface IPaymentStrategy
{
    string Pay(decimal amount);
}

[RegisterStrategy<IPaymentStrategy>("alipay")]
public sealed class AlipayPayment : IPaymentStrategy
{
    public string Pay(decimal amount) => $"Alipay: {amount:C}";
}

// Generated: PaymentStrategyKeys + PaymentStrategyRegistry
var pay = PaymentStrategyRegistry.Instance.Get(PaymentStrategyKeys.Alipay);
Console.WriteLine(pay.Pay(100m));

What's included

Pattern	What you get
Singleton	[GenerateSingleton] → lazy Instance
Factory Registry	[RegisterFactory] → keys + registry (+ async / pooling)
Strategy	[RegisterStrategy] → keys + registry (+ guards / tracing)
Chain of Responsibility	[HandlerOrder] → ordered pipeline (+ guards / tracing)
Composite	[CompositePart] → catalog, forest build, traversal
Decorator	[Decorator] → ordered stack build
Event Aggregator	[RegisterEventHandler] → subscribe-all registries
State	[StateMachine] / [Transition] → tables, guards, hierarchy
Command Router	[RegisterCommandHandler] → 1:1 dispatch + optional pipeline
Step Builder	[GenerateBuilder] → compile-time type-state builder
Work Graph	[WorkGraph] / [WorkStep] → fork–join DAG waves

Diagnostics (DP###), CodeFixes, and deeper API notes live in the documentation site and maintainer design docs.

Docs & samples

Resource	Purpose
DesignPatterns.Docs	User guides (EN / 中文)
DesignPatterns.Samples	Runnable console samples
ROADMAP	Backlog and exploration candidates
CHANGELOG	Release notes

Contributing

Issues and PRs are welcome — please use English for Issue / PR / commit text. See CONTRIBUTING.md for build, test, and module boundaries.

./build.ps1 --target Ci --configuration Release

License

MIT