Tenekon.MethodOverloads.SourceGenerator 0.0.5

Tenekon.MethodOverloads.SourceGenerator

A C# source generator that creates combinatorial extension method overloads by treating a selected parameter window as optional and emitting legal, unique subsequences.

Quickstart

1. Mark a method with [GenerateOverloads] or a type with [GenerateMethodOverloads(Matchers = ...)].
2. (Optional) Add [OverloadGenerationOptions(...)] to control matching and output.
3. Build the project. Generated overloads appear in MethodOverloads_<Namespace>.g.cs.

MSBuild options

Emit attributes only (skip overload generation):

<PropertyGroup>
  <TenekonMethodOverloadsSourceGeneratorAttributesOnly>true</TenekonMethodOverloadsSourceGeneratorAttributesOnly>
</PropertyGroup>

Examples

A) GenerateOverloadsAttribute

Input:

namespace Demo;

using Tenekon.MethodOverloads.SourceGenerator;

public sealed class Calculator
{
    [GenerateOverloads(Begin = nameof(unit))]
    public void Add(int value, string? unit, bool useRounding) { }
}

Output:

namespace Demo;

public static class MethodOverloads
{
    public static void Add(this Calculator source, int value) =>
        source.Add(value, unit: default(string?), useRounding: default(bool));

    public static void Add(this Calculator source, int value, string? unit) =>
        source.Add(value, unit, useRounding: default(bool));

    public static void Add(this Calculator source, int value, bool useRounding) =>
        source.Add(value, unit: default(string?), useRounding);
}

B) Method-level matcher

Input:

namespace Demo;

using Tenekon.MethodOverloads.SourceGenerator;

public sealed class Customer
{
    [GenerateOverloads(Matchers = [typeof(CustomerMatcher)])]
    public void Update(string name, int loyaltyLevel, bool isActive) { }
}

internal interface CustomerMatcher
{
    [GenerateOverloads(nameof(paramB))]
    void Update(int paramA, bool paramB);
}

Output:

namespace Demo;

public static class MethodOverloads
{
    public static void Update(this Customer source, string name, int loyaltyLevel) =>
        source.Update(name, loyaltyLevel, isActive: default(bool));
}

C) Type-level matcher (static target)

Input:

namespace Demo;

using Tenekon.MethodOverloads.SourceGenerator;

[GenerateMethodOverloads(Matchers = [typeof(MathMatchers)])]
public static class MathUtils
{
    public static void Multiply(int left, int right, bool checkedOverflow) { }
}

internal interface MathMatchers
{
    [GenerateOverloads(nameof(paramB))]
    void Multiply(int paramA, bool paramB);
}

Output:

namespace Demo;

public static class MethodOverloads
{
    extension(MathUtils)
    {
        public static void Multiply(int left, int right) =>
            MathUtils.Multiply(left, right, checkedOverflow: default(bool));
    }
}

Key behavior

• Generates overloads from a contiguous optional window of parameters.
• Omits only legal subsets (no ref/out/in removal).
• Dedupes by signature and never duplicates existing overloads.

See docs/generator.md for full behavior and rules.