.NET

1.12.0-rc15

(feat): Generate discriminated unions with:

• Type safety with compile-time checking
• Exhaustive discriminant value matching
• JSON serialization support

Here’s a simple example how to use a shape discriminated union:

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var shape = new Shape(new Circle { Radius = 5 });
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// Type checking
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if (shape.IsCircle) {
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    Console.WriteLine($"Radius: {circle.AsCircle().Radius}");
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}
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// Discriminant value matching
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var area = shape.Match(
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    circle => Math.PI * circle.Radius * circle.Radius,
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    square => square.Length * square.Length,
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    (type, _) => throw new NotSupportedException($"Unknown: {type}")
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);
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// TryAs pattern
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if (shape.TryAsCircle(out var circle)) {
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    Console.WriteLine($"Radius: {circle.Radius}");
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}

This feature is off by default for backward compatibility. To enable it, set use-discriminated-unions to true in the generator configuration.

(feat): Improved serialization tests for generated classes for normal objects and discriminated unions.

(feat): Generated classes now follow the C# convention for odering consts, fields, constructors, properties, methods, operators, and inner classes.