swc-binding/dev.yidafu.swc/Union

Union

@Serializable

sealed class Union

Union types for representing TypeScript union types in Kotlin.

TypeScript union types like string | number | boolean are represented using Union classes (U2, U3) in Kotlin.

Usage Examples

Binary Union (U2)

// TypeScript: string | number
val value: Union.U2<String, Number> = Union.U2.ofA("hello")
// or
val value2: Union.U2<String, Number> = Union.U2.ofB(42)

// Check which type it is
if (value.isA()) {
    println(value.valueOfA()) // "hello"
}

Ternary Union (U3)

// TypeScript: string | number | boolean
val value: Union.U3<String, Number, Boolean> = Union.U3.ofA("hello")
// or
val value2: Union.U3<String, Number, Boolean> = Union.U3.ofB(42)
val value3: Union.U3<String, Number, Boolean> = Union.U3.ofC(true)

Serialization

Union types are automatically serialized/deserialized when used in AST nodes. The serializer will try each type in order until one succeeds.

Inheritors

Types

@Serializable(with = Union.U2.U2Serializer::class)

data class U2<A, B>(val a: A? = null, val b: B? = null) : Union

Binary union type: A | B

@Serializable(with = Union.U3.U3Serializer::class)

data class U3<A, B, C>(val a: A? = null, val b: B? = null, val c: C? = null) : Union

Ternary union type: A | B | C