import type { Int } from ".";
import type { Sub } from "./Sub";
import type { Arg0, Fn } from "../../HKT";

/**
 * Subtract 1 from an {@link Int}.
 *
 * Sig: `(n: Int) => Int`
 */
export type Dec<I extends Int> = Sub<I, 1>;

/**
 * [Fn] Subtract 1 from an {@link Int}.
 *
 * Sig: `(n: Int) => Int`
 */
export default interface DecFn extends Fn<[Int], Int> {
  def: () => Dec<Arg0<this>>;
}