reverse-i-search for vim with fzf

fzf-reverse-i-search.vim

" reverse-i-search
function! s:get_history()
    redir => history
    silent! history
    redir END
  return map(split(history, '\n'), "strpart(v:val, 9)")
endfunction
function! s:run_cmd(cmd)
    execute a:cmd
endfunction
command! FZFCmds call fzf#run({
    \   'source':   <sid>get_history(),
    \   'sink':     function('<sid>run_cmd'),
    \   'options':  '-x --tac +s --prompt="cmd >"',
    \   'right':     '40%'})
nnoremap <leader>r :FZFCmds<CR>