Schema.Union

decode時に上から評価していくので順序が重要

code:ts

const Circle = Schema.Struct({

kind: Schema.Literal("circle"),

radius: Schema.Number

})

const Square = Schema.Struct({

kind: Schema.Literal("square"),

sideLength: Schema.Number

})

const Shape = Schema.Union(Circle, Square)

ただのunionをDiscriminated unionに変換する場合は、Schema.attachPropertySignatureが使える

code:ts

const Circle = Schema.Struct({

radius: Schema.Number

})

const Square = Schema.Struct({

sideLength: Schema.Number

})

const DiscriminatedShape = Schema.Union(

Circle.pipe(Schema.attachPropertySignature("kind", "circle")),

Square.pipe(Schema.attachPropertySignature("kind", "square"))

)