Prevent console line advancing on user input

[Steven Schveighoffer]

On 4/6/23 4:01 AM, anonymouse wrote:
> Wondering if this is possible? Ask a user at input and wait for response:
> 
> write("Is the sky blue? ");
> readf!" %s\n"(response);
> 
> If the user's response is correct, I'd like to change the color of 
> provided response to indicate it was correct then advance to the next 
> line and ask a different question.
> 
> If the user's response is incorrect, I'd like to clear the line and 
> repeat the question without advancing down the screen vertically.
> 
> I'm assuming it can be done by intercepting all input before the console 
> processes them and outputting a '\r', a blank line the length of the 
> screen, and another '\r' to get back to the beginning before reprinting 
> the question. But I have no idea how to intercept the raw input.

You can't intercept raw input. It's the terminal that decides when to 
send you the line of text, you cannot control it via `stdin`.

You need to use a terminal-control library, such as `arsd.terminal`

https://github.com/adamdruppe/arsd/blob/master/terminal.d

-Steve