zsh/Completion/X/_x_extension

#autoload

local expl

_tags extensions || return 1

(( $+_xe_cache )) || _xe_cache=( "${(@)${(@f)$(xdpyinfo)}[(r)number of extensions:*,-1][2,(r)default screen number:*][1,-2]//[      ]}" )

if [[ "$1" = -a ]]; then
  shift

  _wanted extensions expl 'X extensions' \
      compadd "$@" -M 'm:{a-z}={A-Z} r:|-=* r:|=*' - all "$_xe_cache[@]"
else
  [[ "$1" = - ]] && shift

  _wanted extensions expl 'X extensions' \
      compadd "$@" -M 'm:{a-z}={A-Z} r:|-=* r:|=*' -a _xe_cache
fi