effect-io-ai

Package: effect
Module: Match

Match.discriminatorsExhaustive

Matches values by a discriminator field and requires every possible case to be handled.

When to use

Use to define an exhaustive discriminator handler map that finalizes the matcher.

Details

This is the exhaustive variant of discriminators. Each possible discriminator value must have a corresponding handler, so the matcher is finalized directly and does not require Match.exhaustive at the end of the pipeline.

Example (Handling all discriminator cases)

import { Match, pipe } from "effect"

const match = pipe(
  Match.type<
    { type: "A"; a: string } | { type: "B"; b: number } | {
      type: "C"
      c: boolean
    }
  >(),
  Match.discriminatorsExhaustive("type")({
    A: (a) => a.a,
    B: (b) => b.b,
    C: (c) => c.c
  })
)

See

• discriminators for defining discriminator handlers without finalizing the matcher

Signature

declare const discriminatorsExhaustive: <D extends string>(field: D) => <R, Ret, P extends { readonly [Tag in Types.Tags<D, R> & string]: (_: Extract<R, Record<D, Tag>>) => Ret; } & { readonly [Tag in Exclude<keyof P, Types.Tags<D, R>>]: never; }>(fields: P) => <I, F, A, Pr>(self: Matcher<I, F, R, A, Pr, Ret>) => [Pr] extends [never] ? (u: I) => Unify<A | ReturnType<P[keyof P]>> : Unify<A | ReturnType<P[keyof P]>>

Source

Since v4.0.0