Transposing

Tip 191 Printable Monobook Previous Next

created January 3, 2002 · complexity intermediate · author Kontra Gergely · version 5.7

---

Swapping a line with the line directly above or below it is a common task when writing computer software. This tip provides some mappings for normal, insert and visual modes which make this more easily accomplished. Adding the following to your _vimrc file allows you to move a line (or multiple lines) of text up or down within a document using the <Control> and <Up>/<Down> arrow keys. This is similar to the <Alt> and <Up>/<Down> arrow text movement feature in Eclipse.

function! MoveLineUp()
  call MoveLineOrVisualUp(".", "")
endfunction

function! MoveLineDown()
  call MoveLineOrVisualDown(".", "")
endfunction

function! MoveVisualUp()
  call MoveLineOrVisualUp("'<", "'<,'>")
  normal gv
endfunction

function! MoveVisualDown()
  call MoveLineOrVisualDown("'>", "'<,'>")
  normal gv
endfunction

function! MoveLineOrVisualUp(line_getter, range)
  let l_num = line(a:line_getter)
  if l_num - v:count1 - 1 < 0
    let move_arg = "0"
  else
    let move_arg = a:line_getter." -".(v:count1 + 1)
  endif
  call MoveLineOrVisualUpOrDown(a:range."move ".move_arg)
endfunction

function! MoveLineOrVisualDown(line_getter, range)
  let l_num = line(a:line_getter)
  if l_num + v:count1 > line("$")
    let move_arg = "$"
  else
    let move_arg = a:line_getter." +".v:count1
  endif
  call MoveLineOrVisualUpOrDown(a:range."move ".move_arg)
endfunction

function! MoveLineOrVisualUpOrDown(move_arg)
  let col_num = virtcol(".")
  execute "silent! ".a:move_arg
  execute "normal! ".col_num."|"
endfunction

nnoremap <silent> <C-Up> :<C-u>call MoveLineUp()<CR>
nnoremap <silent> <C-Down> :<C-u>call MoveLineDown()<CR>
inoremap <silent> <C-Up> <C-o>:<C-u>call MoveLineUp()<CR>
inoremap <silent> <C-Down> <C-o>:<C-u>call MoveLineDown()<CR>
vnoremap <silent> <C-Up> :<C-u>call MoveVisualUp()<CR>
vnoremap <silent> <C-Down> :<C-u>call MoveVisualDown()<CR>

The above mappings all take a count so 5<C-Up> would move the current line (or visual selection) 5 lines up.

They make use of the :move command to do the movement which avoids overwritting a register which other methods may suffer from. As :move wont move a line to an invalid location an extra check is made to move no further than the start (or end) of the file. The mappings are also careful to restore the original cursor location in the line (or selection) by first getting it with virtcol() and then restoring it with |.

See also

• Swapping characters, words and lines
• upAndDown.vim plugin implementing this tip

References

• :help :move
• :help v:count1
• :help virtcol()
• :help bar