ludic/docs/language/control/kw-while.md

id	name	category	kind	tokens	sig	tip	order
kw-while	while	control	keyword	while	while cond { … }	Loop as long as a condition holds, re-checking it before each pass.	1

A while loop re-evaluates its condition before every pass and runs the body as long as it stays true, so it is the tool when the number of iterations is not known up front. As with if, the condition needs no parentheses and the braces are required. break leaves the loop immediately and continue jumps to the next condition check. When you are simply counting over a fixed range, prefer the numeric for i in a .. b loop, which is clearer and binds a fresh index for you; reach for while when the step or the stopping test is irregular.

program Countdown {
  state CountdownState {
    fuse: int = 5
    elapsed_frames: int = 0
  }

  handler Tick(countdown_st: mut CountdownState) phase Update {
    countdown_st.elapsed_frames = countdown_st.elapsed_frames + 1
    while countdown_st.fuse > 0 and countdown_st.elapsed_frames % 60 == 0 {
      countdown_st.fuse = countdown_st.fuse - 1
      countdown_st.elapsed_frames = countdown_st.elapsed_frames + 1
    }
  }

  handler DrawWorld(countdown_st: CountdownState) phase Render {
    Screen.clear(Color.MidnightBlue)
    Screen.draw_number(x: 8, y: 8, value: countdown_st.fuse, color: Color.Crimson, scale: 3)
    Screen.show()
  }
}