"
" strip_trailing_whitespace.vim: User command to strip both horizontal and
" vertical whitespace in a buffer, with optional range, reporting both
" accurately and restoring the cursor afterwards.
"
" Author: Tom Ryder <tom@sanctum.geek.nz>
" License: Same as Vim itself
"
if exists('g:loaded_strip_trailing_whitespace') || &compatible
finish
endif
if !has('user_commands') || v:version < 600
finish
endif
let g:loaded_strip_trailing_whitespace = 1
" Wrapper function to strip both horizontal and vertical trailing whitespace,
" return the cursor to its previous position, and report changes
function s:Strip(start, end) abort
" Save cursor position
let l:line = line('.')
let l:col = col('.')
" Strip horizontal space
let l:horizontal = s:StripHorizontal(a:start, a:end)
let l:msg = l:horizontal.' trimmed'
let l:changed = l:horizontal > 0
" If we're going to the end, strip vertical space
if a:end == line('$')
let l:vertical = s:StripVertical()
let l:msg = l:msg.', '.l:vertical.' deleted'
let l:changed = l:changed || l:vertical > 0
endif
" Return the cursor
call s:Cursor(l:line, l:col)
" Report what changed
echomsg l:msg
" Return whether anything changed
return l:changed
endfunction
" Strip horizontal trailing whitespace, return the number of lines changed
function s:StripHorizontal(start, end) abort
" Start a count of lines trimmed
let l:count = 0
" Iterate through buffer
let l:num = 1
while l:num <= line('$')
" If the line has trailing whitespace, strip it off and bump the count
let l:line = getline(l:num)
if l:line =~# '\s\+$'
call setline(l:num, substitute(l:line, '\s*$', '', ''))
let l:count = l:count + 1
endif
" Bump for next iteration
let l:num = l:num + 1
endwhile
" Return the number of lines trimmed
return l:count
endfunction
" Strip trailing vertical whitespace, return the number of lines changed
function s:StripVertical() abort
" Store the number of the last line we found with non-whitespace characters
" on it; start at 1 because even if it's empty it's never trailing
let l:eof = 1
" Iterate through buffer
let l:num = 1
while l:num <= line('$')
" If the line has any non-whitespace characters in it, update our pointer
" to the end of the file text
let l:line = getline(l:num)
if l:line =~# '\S'
let l:eof = l:num
endif
" Bump for next iteration
let l:num = l:num + 1
endwhile
" Get the number of lines to delete; if there are any, build a range and
" remove them with :delete, suppressing its normal output (we'll do it)
let l:count = line('$') - l:eof
if l:count
let l:range = (l:eof + 1).',$'
silent execute l:range.'delete'
endif
" Return the number of lines deleted
return l:count
endfunction
" Position the cursor; use cursor() if we have it, :normal if not (Vim 6.0)
function s:Cursor(line, col) abort
if exists('*cursor')
return cursor(a:line, a:col)
else
execute 'normal! '.a:line.'G'.a:col.'|'
return 1
endif
endfunction
" User command for the above
command! -range=% StripTrailingWhitespace
\ call <SID>Strip(<line1>, <line2>)
