Vimのビルトイン補完をぜんぶ動かして候補をまとめられるかと思ったけど無理だった

let s:sid = expand("\<SID>")
let s:cmp_list = []

function! s:start() abort
  let s:cmp_list = []
  call feedkeys($"\<c-x>\<c-f>\<cmd>call {s:sid}f_cmp()\<cr>", 'ni')
endfunction

function! s:f_cmp() abort
  let file_items = complete_info(['items']).items
  call map(file_items, "{'word':v:val.word, 'menu':'file'}")
  call extend(s:cmp_list, file_items)
  if &filetype == 'vim'
    call feedkeys($"\<c-x>\<c-z>\<c-x>\<c-v>\<cmd>call {s:sid}v_cmp()\<cr>", 'ni')
  else
    call feedkeys($"\<c-x>\<c-z>\<c-x>\<c-o>\<cmd>call {s:sid}o_cmp()\<cr>", 'ni')
  endif
endfunction

function! s:v_cmp() abort
  let vim_items = complete_info(['items']).items
  call map(vim_items, "{'word':v:val.word, 'menu':'vim'}")
  call extend(s:cmp_list, vim_items)
  call feedkeys($"\<c-x>\<c-z>\<c-x>\<c-o>\<cmd>call {s:sid}o_cmp()\<cr>", 'ni')
endfunction

function! s:o_cmp() abort
  let omni_items = complete_info(['items']).items
  call map(omni_items, "{'word':v:val.word, 'menu':'omni'}")
  call extend(s:cmp_list, omni_items)
  call feedkeys($"\<c-x>\<c-z>\<c-x>\<c-k>\<cmd>call {s:sid}k_cmp()\<cr>", 'ni')
endfunction

function! s:k_cmp() abort
  let dict_items = complete_info(['items']).items
  call map(dict_items, "{'word':v:val.word, 'menu':'dict'}")
  call extend(s:cmp_list, dict_items)
  call feedkeys($"\<c-x>\<c-z>\<c-x>\<c-u>", 'ni')
endfunction


function! Completefunc(findstart, base) abort
  if a:findstart
    return mi#cmp#findstart()
  endif
  return s:cmp_list
endfunction

set completefunc=Completefunc
inoremap <c-x><c-u> <cmd>call <sid>start()<cr>

  function! s:auto_close_paren() abort
    if slice(get(v:completed_item, 'word', ''), -1) ==# '('
      call feedkeys(")\<left>", 'ni')
    endif
  endfunction
  autocmd CompleteDone * call s:auto_close_paren()

function! mi#cmp#dict_completefunc(findstart, base) abort
  if a:findstart
    return mi#cmp#findstart()
  endif

  let base = substitute(s:cmp_info.lastword, "'", "''", 'g')

  let compl_list = mi#cmp#dict_keywords()

  " if empty(base)
    return compl_list
  " endif

  " Filter the list based on the first few characters the user entered
  " return filter(deepcopy(compl_list), "v:val =~# '^" . escape(base, '\\/.*$^~[]') . ".*'")
endfunction

function! mi#cmp#dict_keywords() abort
  if exists('s:dict_keywords_cache')
    return s:dict_keywords_cache
  endif
  let dict_path_list = split(&dictionary, ',')
  let keywords = []
  for dict_path in dict_path_list
    try
      let lines = readfile(dict_path)
      call extend(keywords, map(lines, "{'word':v:val, 'menu':'dk-" .. dict_path->substitute('.*/', '', '') .. "'}"))
    catch
      echomsg v:exception
    endtry
  endfor
  call uniq(sort(keywords))
  let s:dict_keywords_cache = keywords
  return s:dict_keywords_cache
endfunction