CsEffect.Core 0.3.0

CsEffect.Core

Core types and abstractions for the CsEffect system.

Overview

CsEffect.Core provides the foundational types for defining and using effects without any analyzer dependencies. This lightweight package contains only the essential abstractions needed to create and consume effect-aware APIs.

Core Types

IO Base Class

public class IO { }

Base class for all effect definitions. All effects inherit from IO.

Generic Effect Attribute

[Effect<ConsoleEffect>]
public void WriteToConsole() { ... }

Type-safe attribute for declaring effects on methods and properties.

AttachEffect Attribute

[AttachEffect(typeof(Console), "WriteLine", "Write")]
public sealed class ConsoleEffect : IO { }

Attribute for attaching effects to existing types and specific members.

Effect Severity Control

[EffectSeverity(EffectViolationLevel.Error)]
public sealed class CriticalEffect : IO { }

Configures whether effect violations are warnings or errors.

Usage

Defining Effects

// Base effect for console operations
public class ConsoleEffect : IO { }

// Specific console write effect
[AttachEffect(typeof(Console), "WriteLine", "Write")]
public sealed class ConsoleWriteEffect : ConsoleEffect { }

Using Effects

[Effect<ConsoleWriteEffect>]
public void LogMessage(string message)
{
    Console.WriteLine(message);
}

// Effect hierarchy - IO satisfies ConsoleWriteEffect
[Effect<IO>]
public void DoLogging()
{
    LogMessage("This works due to effect hierarchy");
}

Multiple Effects

[Effect<ConsoleWriteEffect>, Effect<FileWriteEffect>]
public void LogToConsoleAndFile(string message)
{
    Console.WriteLine(message);
    File.WriteAllText("log.txt", message);
}

Benefits

• 🪶 Lightweight: No analyzer or Roslyn dependencies
• 🎯 Pure: Only contains type definitions and attributes
• 🔄 Reusable: Can be used in any .NET project
• 🏗️ Foundational: Base for building effect libraries
• ⚡ Fast: Minimal runtime overhead

Integration

This package is designed to work with:

• CsEffect.System: Pre-built system effects (Console, File, HTTP)
• CsEffect.Analyzer: Development-time effect analysis
• CsEffect: Combined package with analyzer and code fixes

Creating Effect Libraries

// 1. Reference CsEffect.Core
// 2. Define your domain effects
[AttachEffect(typeof(Database), "Execute", "Query")]
public sealed class DatabaseEffect : IO { }

// 3. Use in your APIs
[Effect<DatabaseEffect>]
public User GetUser(int id) => database.Query<User>(id);

License

MIT