Challenges in Designing a Domain-Specific Language (DSL) with TypeScript: A Case Study

declare interface Read {
  read(): Effect.Effect<boolean>;
}

declare interface Write extends Read {
  write<A, E, R>(fa: Effect.Effect<A, E, R>): Effect.Effect<void, E, R>;
}

class ReadTx extends Context.Tag("ReadTx")<ReadTx, Read>() {}
class WriteTx extends Context.Tag("WriteTx")<WriteTx, Write>() {}

function prog(): Effect.Effect<[boolean, string], never, ReadTx | WriteTx> {
  const read: Effect.Effect<boolean, never, ReadTx> = Effect.gen(function* () {
    const readTx = yield* ReadTx;

    return yield* readTx.read();
  });
  const write: Effect.Effect<string, never, WriteTx> = Effect.gen(function* () {
    const writeTx = yield* WriteTx;

    const a = yield* writeTx.read();
    const b = yield* writeTx.write(Effect.succeed(a));

    return "done";
  });

  return Effect.gen(function* () {
    const a = yield* read;
    const b = yield* write;

    return [a, b];
  });
}

declare interface Read {
  read(): Effect.Effect<boolean>;
}

declare interface Write extends Read {
  write<A, E, R>(fa: Effect.Effect<A, E, R>): Effect.Effect<void, E, R>;
}

class ReadTx extends Context.Tag("ReadTx")<ReadTx, Read>() {}
class WriteTx extends Context.Tag("WriteTx")<WriteTx, Write>() {}

function prog(): Effect.Effect<[boolean, string], never, ReadTx | WriteTx> {
  const read: Effect.Effect<boolean, never, ReadTx> = Effect.gen(function* () {
    const readTx = yield* ReadTx;

    return yield* readTx.read();
  });
  const write: Effect.Effect<string, never, WriteTx> = Effect.gen(function* () {
    const writeTx = yield* WriteTx;

    const a = yield* writeTx.read();
    const b = yield* writeTx.write(Effect.succeed(a));

    return "done";
  });

  return Effect.gen(function* () {
    const a = yield* read;
    const b = yield* write;

    return [a, b];
  });
}