Nested

1import { type Writer } from "./core.js";
2import { writeArray, writeTupleNamed } from "./composite.js";
3
4/**
5 * Inverse of `readNested`: `Nested(...)` has no wire format of its own, so for the
6 * `flatten_nested = 0` shape it is simply `Array(Tuple(a T1, b T2, …))`. This thin
7 * alias composes the existing array + named-tuple writers, mirroring the reader:
8 *
9 *   writeNested({ a: writeUInt8, b: writeString })
10 *     === writeArray(writeTupleNamed({ a: writeUInt8, b: writeString }))
11 *
12 * When generating code, prefer inlining (monomorphize the array + tuple) over this
13 * generic composition.
14 */
15export const writeNested = <T extends Record<string, unknown>>(writers: {
16  [K in keyof T]: Writer<T[K]>;
17}): Writer<readonly T[]> => writeArray(writeTupleNamed(writers));