sample.ts

/**
 * @tsplus type Codec
 */
export interface Codec<A> {
  decode: (value: unknown) => E.Either<string, A>;
  encode: (value: A) => unknown;
}

/**
 * @tsplus implicit
 */
export const implicitStrig: Codec<string> = {
  decode: (_) => E.right("" + _),
  encode: (_) => _,
};
/**
 * @tsplus derive Codec<_, _> 10
 */
export declare function deriveStruct<A>(
  ...rules: A extends Record<string, any>
    ? [
        {
          [K in keyof A]: Codec<A[K]>
        }
      ]
    : never
): Codec<A>;

/**
 * @tsplus derive Codec<_, _> 10
 */
 export declare function deriveLiteralString<A extends string>(
  ...[value]: [value: A]
): Codec<A>


// esempio
interface GetUserRequest {
  _tag: "GetUser"
  username: string
}

interface GetUserResponse {
  name: string
  surname: string
}

type Message<Req, Res> = {
  request: Codec<Req>
  response: Codec<Res>
}

const codecUser = Derive<Message<GetUserRequest, GetUserResponse>>("explain");