use moi/util/condition
use moi/util/file

var extensions = [ tar bz2 zip gz lz4 sz xz zst rar ]

fn complete [@argv]{
  var m = $argv[-1]
  var type = (condition:cset (eq $m '') prefix deep-prefix)
  file:match-extensions &type=$type $m $@extensions
}

edit:completion:arg-completer[desarchiver] = $complete~