scroll_mapping.vimrc.vim

nnoremap <SID>[Scroll] <Nop>

if 0
  nmap j j<SID>[Scroll]
  nnoremap <script><expr> <SID>[Scroll]j
        \ (line('.') == line('$') ? "L\<SID>[Scroll]" : "j\<SID>[Scroll]")

  nmap k k<SID>[Scroll]
  nnoremap <script><expr> <SID>[Scroll]k
        \ (line('.') == 1 ? "H\<SID>[Scroll]" : "k\<SID>[Scroll]")
endif

nmap <C-d> <C-d><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]d
      \ (line('.') == line('$') ? "L\<SID>[Scroll]" : "\<C-d>\<SID>[Scroll]")

nmap <C-u> <C-u><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]u
      \ (line('.') == 1 ? "H\<SID>[Scroll]" : "\<C-u>\<SID>[Scroll]")

nmap <C-f> <C-f><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]f
      \ (line('.') == line('$') ? "L\<SID>[Scroll]" : "\<C-f>\<SID>[Scroll]")

nmap <C-b> <C-b><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]b
      \ (line('.') < winheight(0) ? "H\<SID>[Scroll]" : "\<C-b>\<SID>[Scroll]")

nmap <C-e> <C-e><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]e
      \ (line('.') == line('$') ? "L\<SID>[Scroll]" : "\<C-e>\<SID>[Scroll]")

nmap <C-y> <C-y><SID>[Scroll]
nnoremap <script><expr> <SID>[Scroll]y
      \ (line('.') == 1 ? "H\<SID>[Scroll]" : "\<C-y>\<SID>[Scroll]")