On Friday, 20 May 2022 at 14:59:07 UTC, Alexander Zhirov wrote:
> I have a loop spinning, I want to pause in it in order to repeat the next iteration. An error is displayed during compilation.

The error has nothing to do with the sleep

> source/app.d(32,5): Warning: statement is not reachable
> Error: warnings are treated as errors
>        Use -wi if you wish to treat warnings only as informational.


this is saying the stuff after your `while(true)` is never reached because it is an infinite loop.

On 5/20/22 07:59, Alexander Zhirov wrote:
> I have a loop spinning, I want to pause in it in order to repeat the
> next iteration. An error is displayed during compilation.
>
> ```d

>      while (true)
>      {

We are in an unconditional loop which is also infinite.

>      }

But you have code after the loop:

>      file.close();
>
>      return 0;
> }
>
> ```

> source/app.d(32,5): Warning: statement is not reachable

That is warning you that your code cannot be executed. One option:

1) Change main's return type to 'void' and remove 'return 0'. (The program will automatically return 0 to its starter upon successful completion and non-zero upon an uncaught exception.)


2) Remove file.close(), which is not needed because File is an RAII type; its objects close their handles in their destructors automatically.

However, since your code never gets to that point, you may have unflushed data when you terminate the program. I think it depends on your file system whether '\n' which is implied at ends of writeln is a flush trigger.

3) Regardless, I would add file.flush() after the last writeln in the loop.

> Is there any way to pause to slow down the cycle?

That is correct. There is a more pleasant syntax that takes advantage of D's UFCS:

  Thread.sleep(10.seconds);

Ali

Or you could capture a sigint and close the file then.