Backspace over whitespace

" bairui's <bs>   ;)
" <bs> will effectively undo <cr> when autoindent is on
inoremap <expr> <bs> BackspaceIgnoreIndent()
function! BackspaceIgnoreIndent()
  if search('^\s*\%#', 'bn') != 0
    return "\<c-u>\<c-h>"
  else
    return "\<c-h>"
  endif
endfunction

finish

test

  this