Problem Statement

The task is to implement a   metronome. The metronome should be capable of producing high and low audio beats, accompanied by a visual beat indicator, and the beat pattern and tempo should be configurable. For the purpose of this task, it is acceptable to play sound files for production of the beat notes, and an external player may be used. However, the playing of the sounds should not interfere with the timing of the metronome. The visual indicator can simply be a blinking red or green area of the screen (depending on whether a high or low beat is being produced), and the metronome can be implemented using a terminal display, or optionally, a graphical display, depending on the language capabilities. If the language has no facility to output sound, then it is permissible for this to implemented using just the visual indicator.

Let's start with the solution:

import "timer" for Timer
import "io" for Stdout

var metronome = Fn.new { |bpm, bpb, maxBeats|
    var delay = (60000/bpm).floor
    var beats = 0
    while (true) {
        Timer.sleep(delay)
        System.write((beats % bpb == 0) ? "\n\aTICK " : "\atick ")
        Stdout.flush()
        beats = beats + 1
        if (beats == maxBeats) break
    }
    System.print()
}

metronome.call(120, 4, 20) // limit to 20 beats