Reference Generated Code From Source Code

With Metalama, your source code can reference generated code as if it were part of the original source. This marks a significant step forward from previous MSIL-based generation methods, where code additions remained invisible to the source code.

Benefits

• Idiomatically C#. No need for cumbersome constructs like in MSIL-based approaches.
• IntelliSense. Code completion works seamlessly with generated code.

Example

Consider a scenario where an aspect implements the Memento pattern for the Fish class. In this case, the source code will “recognize” that the class implements the IMementoable interface, allowing you to invoke the generated SaveToMemento and RestoreMemento methods. IntelliSense and design-time code verification will function as expected.

Suppose we have the following class in the source code:

[Memento]
public sealed partial class Fish
{
    public string? Name { get; set; }
    public string? Species { get; set; }
    public DateTime DateAdded { get; set; }
}

The [Memento] aspect automatically implements the IMementoable interface, defined as follows:

public interface IMementoable
{
  IMemento SaveToMemento();
  void RestoreMemento( IMemento memento );
}

Another part of the source can use the IMementoable interface and its methods as if they were defined directly in the source code:

var fish = new Fish() { Name = "Hannibal", Species = "Tilapia" };

// Save by using the generated SaveToMemento method.
var memento = fish.SaveToMemento();

// Change
fish.Name = "Shark";

// Undo change by using the generated RestoreMemento method.
fish.RestoreMemento(memento);