在可视模式下映射命令会导致错误E481：不允许范围

我正在尝试在Neovim中进行键盘绑定，以将选定的块发送到打开的Neovim终端。我已将这些答案用作准则https://vi.stackexchange.com/a/3390/3405 https://stackoverflow.com/a/6271254/859391

尽管我正在尝试在选择了可视行的情况下调用命令，我不断收到“ No Range Allowed”错误。我缺少明显的东西吗？

function! s:get_visual_selection()
  " Why is this not a built-in Vim script function?!
  let [lnum1, col1] = getpos("'<")[1:2]
  let [lnum2, col2] = getpos("'>")[1:2]
  let lines = getline(lnum1, lnum2)
  let lines[-1] = lines[-1][: col2 - (&selection == 'inclusive' ? 1 : 2)]
  let lines[0] = lines[0][col1 - 1:]
  return join(lines, "\n")
endfunction

augroup Terminal
  au!
  au TermOpen * let g:last_terminal_job_id = b:terminal_job_id
augroup END

function! REPLSend(lines)
  call jobsend(g:last_terminal_job_id, lines[0])
  call jobsend(g:last_terminal_job_id, "\r") " needed for the way REPL handles the input
endfunction

command! REPLSendLine call REPLSend([s:get_visual_selection()])
vnoremap <silent> <leader>l :REPLSendLine<cr>
" leader is <Space>