import { ElementOf, IsEmpty, List } from "../../list";
import { Satisfies, Unreachable } from "../../type";
import { $, HKT, _, I } from "..";
type _$Exists<P extends HKT<any, boolean>, L extends List> = L extends readonly [...infer Init, infer Last] ? $<P, Last> extends true ? true : _$Exists<P, Init> : $<P, ElementOf<L>> extends true ? true : false;
/**
 * checks whether there exists some element of list `L` that satisfies predicate `P`.
 *
 * an empty list is vacuously unsatisfied (i.e. returns false)
 *
 * @param P   - HKT predicate to operate on each individual element of `L`
 * @param L   - the list to search
 *
 * @since 0.0.2
 */
export type $Exists<P extends HKT<any, boolean>, L extends List> = IsEmpty<L> extends true ? false : L extends readonly [infer H, ...infer T] ? $<P, H> extends true ? true : $Exists<P, T> : L extends readonly [...any, any] ? _$Exists<P, L> : L extends {
    0?: any;
} ? L extends readonly [_?: infer H, ...__: infer T] ? $<P, H> extends true ? true : $Exists<P, T> : Unreachable : false;
/**
 * checks whether there exists some element of the input list satisfies predicate `P`
 *
 * an empty list is vacuously unsatisfied (i.e. returns false)
 *
 * @since 0.0.2
 */
export interface Exists<P extends HKT<any, boolean>> extends HKT {
    [HKT.i]: Satisfies<_<this>, List<I<P>>>;
    [HKT.o]: $Exists<P, I<this>>;
}
export {};
//# sourceMappingURL=exists.d.ts.map