Flush the   keyboard   buffer.

This reads characters from the keyboard input and
discards them until there are no more currently buffered,  
and then allows the program to continue.

The program must not wait for users to type anything.

import "io" for Stdin
 
System.print("Press some keys followed by enter.")
while (true) {
   var b = Stdin.readByte() // reads and removes a key from the buffer
   System.print("Removed key with code %(b).")
   if (b == 10) break      // buffer will be empty when enter key pressed
}
System.print("Keyboard buffer is now empty.")