Recreate a browser's run-loop

example.coffee

# The code ported to ruby
results  = []
rounds   = 5
callback = (result) ->
  results.push result
  
  if results.length is rounds
    console.log "All #{rounds} requests have completed! Here they are:", results

[1 .. rounds].forEach (item) ->
  setTimeout (-> callback(item)), item * 1000
  
console.log "This line should appear on top of the output"

example.rb

require 'runner'
Runner.new do
  results  = []
  rounds   = 5
  callback = ->(result) {
    results.push result

    if results.size == rounds
      puts "All #{rounds} requests have completed! Here they are:", *results
    end
  }
  1.upto(rounds) do |item|
    timeout 0 do callback.call(item) end
  end

  puts "This line should appear on top of output"
end

runner.rb

class Runner
  Delayed = Struct.new(:id, :execute_at, :reschedule, :work) do
    def <=>(other)
      execute_at <=> other.execute_at
    end
  end

  def initialize(&block)
    @id      = 0
    @delayed = []
    if block
      instance_eval(&block)
      run
    end
  end

  def timeout(milliseconds, &work)
    @delayed << Delayed.new(@id+=1, Time.now+milliseconds.fdiv(1000), nil, work)
    @delayed.sort!
  end

  def intervall(milliseconds, &work)
    @delayed << Delayed.new(@id+=1, Time.now+milliseconds.fdiv(1000), milliseconds, work)
    @delayed.sort!
  end

  def clear_timeout(id)
    @delayed.delete_at(@delayed.find_index { |work| work.id == id })
  end

  def run
    until @delayed.empty?
      delayed = @delayed.shift
      delayed.work.call
      if delayed.reschedule
        delayed.execute_at = Time.now+delayed.reschedule.fdiv(1000)
        @delayed << delayed
        @delayed.sort!
      end
    end
  end
end