if &compatible
  set nocompatible
endif
let s:compl_key_dict = {
      \ char2nr("\<C-l>"): "\<C-x>\<C-l>",
      \ char2nr("\<C-n>"): "\<C-x>\<C-n>",
      \ char2nr("\<C-p>"): "\<C-x>\<C-p>",
      \ char2nr("\<C-k>"): "\<C-x>\<C-k>",
      \ char2nr("\<C-t>"): "\<C-x>\<C-t>",
      \ char2nr("\<C-i>"): "\<C-x>\<C-i>",
      \ char2nr("\<C-]>"): "\<C-x>\<C-]>",
      \ char2nr("\<C-f>"): "\<C-x>\<C-f>",
      \ char2nr("\<C-d>"): "\<C-x>\<C-d>",
      \ char2nr("\<C-v>"): "\<C-x>\<C-v>",
      \ char2nr("\<C-u>"): "\<C-x>\<C-u>",
      \ char2nr("\<C-o>"): "\<C-x>\<C-o>",
      \ char2nr('s'): "\<C-x>s",
      \ char2nr("\<C-s>"): "\<C-x>s"
      \}

let s:hint_i_ctrl_x_msg_lines = [
      \ '<C-l>: While lines',
      \ '<C-n>: keywords in the current file',
      \ "<C-k>: keywords in 'dictionary'",
      \ "<C-t>: keywords in 'thesaurus'",
      \ '<C-i>: keywords in the current and included files',
      \ '<C-]>: tags',
      \ '<C-f>: file names',
      \ '<C-d>: definitions or macros',
      \ '<C-v>: Vim command-line',
      \ '<C-u>: User defined completion',
      \ '<C-o>: omni completion',
      \ 's: Spelling suggestions'
      \]
let s:hint_i_ctrl_x_msg = join(s:hint_i_ctrl_x_msg_lines, "\n")

function! s:hint_i_ctrl_x() abort " {{{
  echo (&lines > len(s:hint_i_ctrl_x_msg_lines)) ? s:hint_i_ctrl_x_msg : join(s:hint_i_ctrl_x_msg_lines[: &lines - 2], "\n")
  return get(s:compl_key_dict, getchar(), '')
endfunction " }}}

inoremap <silent><expr><C-x>  <SID>hint_i_ctrl_x()