import type { Args, Fn } from "../HKT";
import type { AssertStr, IsNever } from "../helpers";

/**
 * Convert `null` to a string.
 *
 * Sig: `(n: null) => string`
 */
export type ToStr<N extends null> = AssertStr<IsNever<N> extends true ? never : "null">;

/**
 * [Fn] Convert `null` to a string.
 *
 * Sig: `(n: null) => string`
 */
export default interface ToStrFn extends Fn<[null], string> {
  def: ([n]: Args<this>) => ToStr<typeof n>;
}