import { Fn } from '../Fn';
import { Invoke } from '../Invoke';
import { HandleNever, IfInvoking, Input } from '../utils';
export interface FlatMap<T extends Fn<unknown, unknown[]>> extends Fn<T['in'][], T['out'][number][]> {
    out: IfInvoking<this, InvokeFlatMap<T, Input<this>>, T['out'][number][]>;
}
export type InvokeFlatMap<T extends Fn<unknown, unknown[]>, In extends T['in'][]> = Internal<T, In, []>;
type Internal<T extends Fn<unknown, unknown[]>, In extends T['in'][], Acc extends T['out'][number][]> = In extends [infer First extends T['in'], ...infer Rest extends T['in'][]] ? Internal<T, Rest, [...Acc, ...Invoke<T, HandleNever<First, In[0]>>]> : Acc;
export {};