Delly.Modeling 2026.6.22

Delly.Modeling

A .NET modeling library that provides source code generation capabilities for object modeling, enabling reflection-like property access and manipulation at compile time through Roslyn Source Generators.

Features

• Compile-time generation: Property access code is generated at compile time, eliminating runtime reflection overhead
• AOT-compatible: Works with Ahead-of-Time compilation (e.g., Native AOT)
• High performance: Up to 10x faster than traditional reflection-based property access
• Type safety: Compile-time type checking while maintaining dictionary-like property access
• Zero runtime allocation: Uses static singleton instances for models
• Framework support: .NET Standard 2.0 and .NET 6.0+

Installation

NuGet Packages

dotnet add package Delly.Modeling
dotnet add package Delly.Modeling.Generator

Quick Start

Mark your class with the [Modelable] attribute and declare it as partial:

using Delly.Modeling;

[Modelable]
public partial class User(string id)
{
    public string Id { get; } = id;
    public string Name { get; set; } = string.Empty;
    public string? Password { get; set; }
    public long Age { get; set; }
}

The source generator will automatically generate code that enables property access:

// Get the model for the User class
var model = User.GetModel();

// Get all property names
var properties = model.GetProperties();
// Returns array of property model objects

// Get a specific property
var ageProperty = model.GetProperty(nameof(User.Age));

// Get property value
var age = ageProperty?.GetValue(user);

// Set property value
ageProperty?.SetValue(user, 25L);

Supported Types

The library includes built-in models for common types:

• string → StringModel
• int / Int32 → Int32Model
• long / Int64 → Int64Model
• bool / Boolean → BooleanModel
• double / Double → DoubleModel
• decimal / Decimal → DecimalModel
• DateTime → DateTimeModel
• Guid → GuidModel

Performance

The source generator approach provides significant performance benefits over reflection:

Benchmark results may vary depending on hardware and runtime

Project Structure

• Delly.Modeling - Core modeling library (.NET Standard 2.0, .NET 6.0)

  • ModelableAttribute - Attribute to mark classes for source generation
  • IModel - Interface for model objects
  • IModelProperty - Interface for model properties
  • Built-in type models in the Models namespace

• Delly.Modeling.Generator - Roslyn Source Generator (.NET Standard 2.0)

  • ModelableSourceGenerator.cs - Main source generator implementation
  • ModelableSyntaxReceiver.cs - Syntax receiver for collecting [Modelable] classes

• Deme - Performance benchmark demonstration application (.NET 10.0 with AOT)

• NugetDemo - NuGet package usage demonstration

Building and Running

# Build the solution
dotnet build

# Run the demo application (with benchmark)
cd Deme
dotnet run

How It Works

1. Mark a class with [Modelable] and declare it as partial
2. The source generator scans for classes with this attribute at compile time
3. Generated code includes:
   • A static GetModel() method that returns the model singleton
   • Property model classes implementing IModelProperty for each property
   • A main model class implementing IModel with property access methods
4. All generated code is emitted to obj/Generated and compiled with your project

License

See LICENSE file for details.