import { Fn } from '../Fn';
import { Invoke } from '../Invoke';
import { Reducer } from '../types';
import { HandleNever, IfInvoking, Input } from '../utils';
export type ReducerFn<Item, Accumulator> = Fn<Reducer<Item, Accumulator>, Accumulator>;
export interface Reduce<F extends ReducerFn<unknown, unknown>, InitialValue extends F['out']> extends Fn<F['in']['current'][], F['out']> {
    out: IfInvoking<this, InvokeReduce<F, InitialValue, Input<this>>, F['out']>;
}
export type InvokeReduce<F extends ReducerFn<unknown, unknown>, InitialValue extends F['out'], List extends F['in']['current'][]> = List extends [
    infer First extends F['in']['current'],
    ...infer Rest extends F['in']['current'][]
] ? InvokeReduce<F, Invoke<F, Reducer<InitialValue, HandleNever<First, List[0]>>>, Rest> : InitialValue;