Java result. Source: https://x.com/ptr_to_joel/status/1955055394725958101

Result.java

sealed interface Result<T> {
  record Ok<T>(T value) implements Result<T> {};
  record Err<T>(Throwable err) implements Result<T> {};

  static <T> Result<T> of (Callable<T> code) {
    try {
      return new Ok<T>(code.call());
    } catch (Throwable throwable) {
      return new Err<T>(throwable);
    }
  }

  default <R> Result<R> map(Function<T, R> mapper) {
    return switch (this) {
      case Ok<T> ok -> Result.of(() -> mapper.apply(ok.value()));
      case Err<T> err -> new Err<R>(err.err()); 
    }
  }
}