Function struct

packages/typeclass/src/Monoid.ts:101–111

(
  fields: R
)

 * @since 0.24.0
 */
export const struct = <R extends { readonly [x: string]: Monoid<any> }>(
  fields: R
): Monoid<{ readonly [K in keyof R]: [R[K]] extends [Monoid<infer A>] ? A : never }> => {
  const empty = {} as any
  for (const k in fields) {
    if (Object.prototype.hasOwnProperty.call(fields, k)) {
      empty[k] = fields[k].empty
    }
  }
  return fromSemigroup(semigroup.struct(fields), empty)
}