use builtin; use str; set edit:completion:arg-completer[my-app] = {|@words| fn spaces {|n| builtin:repeat $n ' ' | str:join '' } fn cand {|text desc| edit:complex-candidate $text &display=$text' '(spaces (- 14 (wcswidth $text)))$desc } var command = 'my-app' for word $words[1..-1] { if (str:has-prefix $word '-') { break } set command = $command';'$word } var completions = [ &'my-app'= { cand -h 'Print help' cand --help 'Print help' } ] $completions[$command] }