Show which line is executing

execution_visualizer.rb

# Please convert this to a Sublime Text 3 plugin. 
require 'curses'
Curses.init_screen
SOURCE_LINES = File.read(__FILE__).split("\n")
TracePoint.trace(:line) do |tp|
  Curses.clear
  SOURCE_LINES.each_with_index do |src,row|
    Curses.setpos(row, 0)
    Curses.addstr(src)
  end
  Curses.setpos(tp.lineno-1, 0)
  Curses.refresh
end
loop do
  sleep 0.5
  sleep 0.5
  sleep 0.5
end
Curses.close