_mix_refresh () {
    if [ -f .mix_tasks ]; then
      rm .mix_tasks
    fi
    echo "Generating .mix_tasks..." > /dev/stderr
    _mix_generate
    cat .mix_tasks
  }
  
  _mix_does_task_list_need_generating () {
    [ ! -f .mix_tasks ];
  }
  
  _mix_generate () {
    mix --help | grep -v 'iex -S' | tail -n +2 | cut -d " " -f 2 > .mix_tasks
  }
  
  _mix () {
    if [ -f mix.exs ]; then
      if _mix_does_task_list_need_generating; then
        echo "
  Generating .mix_tasks..." > /dev/stderr
        _mix_generate
      fi
      compadd `cat .mix_tasks`
    fi
  }
  
  compdef _mix mix
  alias mix_refresh='_mix_refresh'