effect-io-ai

Package: effect
Module: Tuple

Tuple.renameIndices

Renames tuple indices by providing an array of stringified source indices. Each position in the array specifies which index to read from (e.g., ["2", "1", "0"] reverses a 3-element tuple).

When to use

Use to reorder tuple elements while preserving index-specific types.

Details

The mapping returns a tuple in the requested index order.

Gotchas

The mapping uses stringified source indices, not arbitrary names.

Example (Swapping elements)

import { pipe, Tuple } from "effect"

const result = pipe(
  Tuple.make("a", "b", "c"),
  Tuple.renameIndices(["2", "1", "0"])
)
console.log(result) // ["c", "b", "a"]

See

• evolve – transform element values instead of positions

Signature

declare const renameIndices: { <const T extends ReadonlyArray<unknown>, const M extends { readonly [I in keyof T]?: `${keyof T & string}`; }>(mapping: M): (self: T) => { [I in keyof T]: I extends keyof M ? M[I] extends keyof T ? T[M[I]] : T[I] : T[I]; }; <const T extends ReadonlyArray<unknown>, const M extends { readonly [I in keyof T]?: `${keyof T & string}`; }>(self: T, mapping: M): { [I in keyof T]: I extends keyof M ? M[I] extends keyof T ? T[M[I]] : T[I] : T[I]; }; }

Source

Since v4.0.0