AutoComparable

Generates IComparable<T>

---

Installation

dotnet add package VoloGen.Comparable
dotnet add package VoloGen.Comparable.Generator

Requirements

The annotated type must:

• Be declared as partial
• Not be static
• Define one core method:
  • static int Compare(T left, T right) – your comparison logic

What Gets Generated

Generated Member	Delegates To
int CompareTo(T other)	Compare(this, other)
int IComparable.CompareTo(object? obj)	Compare(this, (T)obj) with type check
operator <(T, T)	Compare(left, right) < 0
operator >(T, T)	Compare(left, right) > 0
operator <=(T, T)	Compare(left, right) <= 0
operator >=(T, T)	Compare(left, right) >= 0
operator ==(T, T)	Compare(left, right) == 0
operator !=(T, T)	Compare(left, right) != 0

When [AutoEquality] is also present, this generator takes ownership of == and != so they delegate to Compare rather than Equal. This avoids duplicate operator declarations.

Example

Struct

using VoloGen;

[AutoComparable]
public partial struct Amount
{
    private readonly decimal _value;

    public Amount(decimal value)
    {
        _value = value;
    }

    public static int Compare(Amount left, Amount right)
    {
        return left._value.CompareTo(right._value);
    }

    public override bool Equals(object? obj)
    {
        return obj is Amount other && _value == other._value;
    }

    public override int GetHashCode()
    {
        return _value.GetHashCode();
    }
}

Multi-Field Comparison

using VoloGen;

[AutoComparable]
public partial struct Coordinate
{
    private readonly int _x;
    private readonly int _y;

    public static int Compare(Coordinate left, Coordinate right)
    {
        var xCompare = left._x.CompareTo(right._x);
        if (xCompare != 0)
        {
            return xCompare;
        }
        return left._y.CompareTo(right._y);
    }
}

Usage

var a = new Amount(10.00m);
var b = new Amount(30.00m);
var c = new Amount(50.00m);

Console.WriteLine(a < b);   // True
Console.WriteLine(c > b);   // True
Console.WriteLine(a <= a);  // True
Console.WriteLine(a == a);  // True

// IComparable<T> -- works with sorting
var amounts = new[] { c, a, b };
Array.Sort(amounts);
// amounts: 10, 30, 50

Diagnostics

ID	Trigger
VG0002	Type is not partial
VG0003	Type is static
VG0005	Missing Compare method