_zimfw_list_unuseds() {
  local -i i=1
  local -a zinstalled=(${ZIM_HOME}/modules/*(N/:t)) subdirs
  # Search into subdirectories
  while (( i <= ${#zinstalled} )); do
    if (( ${_zmodules[(I)${zinstalled[i]}/*]} || ${_zdisableds[(I)${zinstalled[i]}/*]} )); then
      subdirs=(${ZIM_HOME}/modules/${zinstalled[i]}/*(N/:t))
      zinstalled+=(${zinstalled[i]}/${^subdirs})
      zinstalled[i]=()
    else
      (( i++ ))
    fi
  done
  # Unused = all installed modules not in _zmodules and _zdisableds
  _zunuseds=(${${zinstalled:|_zmodules}:|_zdisableds})
  local zunused
  for zunused in ${_zunuseds}; do
    _zimfw_print -PR "%B${zunused}:%b ${ZIM_HOME}/modules/${zunused}${1}"
  done
}