Make vim keep mark when I delete the line the mark is on

Question

How can I get vim to preserve marks when I delete the line the mark is on (i.e., automatically move the mark to the line immediately above or below the marked line)

Answer 1

One addition to @Kurt Hutchinson answer: there is a possibility to define an operator function. In this case you don’t need to define a mapping for every deletion command, but instead redefine d:

let s:typetochar={
            \ 'char': 'v',
            \ 'line': 'V',
            \'block': "\",
        \}
function! DeleteOperator(type)
    execute 'lockmarks normal! `["'.v:register.'d'.s:typetochar[a:type].'`]'
endfunction
function! s:Delete()
    set opfunc=DeleteOperator
    return 'g@'
endfunction
nnoremap  d  Delete()
nnoremap  dd Delete().'g@'
vnoremap d :lockmarks normal! gvd

Note the dd mapping: as d is actually using g@, there should be dg@ (expanded to g@g@) where you type dd. So in order to use cleaner dd you have to create a mapping.