edit:
it was a mistake to say that 'e' is returning $null for <esc> pressed during the loop, that was a mis-test that didn't have the 'f' switch. And to clarify, the counter example below returns $yes regardless if <enter/spacebar> are pressed during/after the loop.
//var %end $ticksqpc + 2000 | while ($ticksqpc < %end) noop | echo -a : $input(prompt,nv,title,default)
