#compdef -condition-

local prev="$words[CURRENT-1]"

if [[ "$prev" = -o ]]; then
  _options
elif [[ "$prev" = -([no]t|ef) ]]; then
  _files
else
  local ret=1 expl

  _files && ret=0
  _description expl parameter
  compgen "$expl[@]" -v && ret=0

  return ret
fi