import type { Prepend } from "./Prepend";
import type { Args, Fn } from "../HKT";

/**
 * Concatenate two strings.
 *
 * It is actually an alias of {@link Prepend}.
 *
 * Sig: `(s1: string, s2: string) => string`
 */
export type Concat<S1 extends string, S2 extends string> = Prepend<S1, S2>;

/**
 * [Fn] Concatenate two strings.
 *
 * It is actually an alias of {@link Prepend}.
 *
 * Sig: `(s1: string, s2: string) => string`
 */
export default interface ConcatFn extends Fn<[string, string], string> {
  def: ([s1, s2]: Args<this>) => Prepend<typeof s1, typeof s2>;
}