zsh/Completion/Commands/_complete_help

#compdef -k complete-word \C-xh

_complete_help() {
  setopt localoptions nullglob rcexpandparam extendedglob
  unsetopt markdirs globsubst shwordsplit nounset ksharrays

  local _sort_tags=_help_sort_tags text i j k
  typeset -A help_funcs help_tags help_sfuncs help_styles

  compadd() { return 1 }
  zstyle() {
    local _f="${${(@)${(@)funcstack[2,(i)_(main_complete|complete|approximate|normal)]}:#_(wanted|requested|loop|try)}% *}"

    [[ -z "$_f" ]] && _f="${${(@)funcstack[2,(i)_(main_complete|complete|approximate|normal)]}:#_(wanted|requested|loop|try)}"

    if [[ "$help_sfuncs[$2]" != *${_f}* ||
          "$help_styles[${2}${_f}]" != *${3}* ]]; then
      [[ "$help_sfuncs[$2]" != *${_f}* ]] &&
          help_sfuncs[$2]="${help_sfuncs[$2]}:${_f}"
      local _t

      case "$1" in
      -s) _t='[string] ';;
      -a) _t='[array]  ';;
      -h) _t='[assoc]  ';;
      *)  _t='[boolean]';;
      esac
      help_styles[${2}${_f}]="${help_styles[${2}${_f}]},${_t} ${3}:${_f}"
    fi

    # No need to call the completers more than once with different match specs.

    if [[ "$3" = matcher-list ]]; then
      eval "${4}=( '' )"
    else
      builtin zstyle "$@"
    fi
  }

  _main_complete

  unfunction compadd zstyle

  for i in "${(@ok)help_funcs}"; do
    text="${text}
tags in context :completion:${i}:"
    tmp=()
    for j in "${(@s.:.)help_funcs[$i][2,-1]}"; do
      tmp=( "$tmp[@]" "${(@s.,.)help_tags[${i}${j}][2,-1]}" )
    done
    zformat -a tmp '  (' "$tmp[@]"
    tmp=( '
    '${^tmp}')' )
    text="${text}${tmp}"
  done

  if [[ ${NUMERIC:-1} -ne 1 ]]; then
    text="$text
"
    for i in "${(@ok)help_sfuncs}"; do
      text="${text}
styles in context ${i}"
      tmp=()
      for j in "${(@s.:.)help_sfuncs[$i][2,-1]}"; do
        tmp=( "$tmp[@]" "${(@s.,.)help_styles[${i}${j}][2,-1]}" )
      done
      zformat -a tmp '  (' "$tmp[@]"
      tmp=( '
    '${^tmp}')' )
      text="${text}${tmp}"
    done
  fi
  compstate[list]='list force'
  compstate[insert]=''

  compadd -UX "$text[2,-1]" -n ''
}

_help_sort_tags() {
  local f="${${(@)${(@)funcstack[3,(i)_(main_complete|complete|approximate|normal)]}:#_(wanted|requested|loop|try)}% *}"

  if [[ "$help_funcs[$curcontext]" != *${f}* ||
        "$help_tags[${curcontext}${f}]" != *(${(j:|:)~argv})* ]]; then
    [[ "$help_funcs[$curcontext]" != *${f}* ]] &&
        help_funcs[$curcontext]="${help_funcs[$curcontext]}:${f}"
    help_tags[${curcontext}${f}]="${help_tags[${curcontext}${f}]},${argv}:${f}"
    comptry "$@"
  fi
}

_complete_help "$@"