effect-io-ai

Package: effect
Module: Utils

Utils.SingleShotGen

Yields its wrapped value exactly once through an IterableIterator.

When to use

Use to implement [Symbol.iterator]() on Effect-like types so they can be yield*-ed inside generator functions, such as Effect.gen and Option.gen.

Details

The first call to next() returns { value: self, done: false }. Every subsequent call returns { value: a, done: true } where a is the argument passed to next(). [Symbol.iterator]() returns a new SingleShotGen wrapping the same value, so the outer type can be iterated multiple times.

Example (Yielding a wrapped value in a generator)

import { Utils } from "effect"

const gen = new Utils.SingleShotGen<string, number>("hello")

// First call yields the wrapped value
console.log(gen.next(0))
// { value: "hello", done: false }

// Second call signals completion with the provided value
console.log(gen.next(42))
// { value: 42, done: true }

See

• Gen for the type-level signature that relies on SingleShotGen

Signature

declare class SingleShotGen<T, A> { constructor(self: T) }

Source

Since v2.0.0