effect-io-ai

Package: effect
Module: Struct

Struct.makeCombiner

Creates a Combiner for a struct shape by providing a Combiner for each property. When two structs are combined, each property is merged using its corresponding combiner.

When to use

Use when you need to merge two same-shape records by combining each property independently, such as summing counters or concatenating strings.

Details

Pass omitKeyWhen to drop properties whose merged value matches a predicate, such as omitting zero counters.

Example (Combining struct properties)

import { Number, String, Struct } from "effect"

const C = Struct.makeCombiner<{ readonly n: number; readonly s: string }>({
  n: Number.ReducerSum,
  s: String.ReducerConcat
})

const result = C.combine({ n: 1, s: "hello" }, { n: 2, s: " world" })
console.log(result) // { n: 3, s: "hello world" }

See

• makeReducer – like makeCombiner but with an initial value

Signature

declare const makeCombiner: <A>(combiners: { readonly [K in keyof A]: Combiner.Combiner<A[K]>; }, options?: { readonly omitKeyWhen?: ((a: A[keyof A]) => boolean) | undefined; }) => Combiner.Combiner<A>

Source

Since v4.0.0