Set a mark to its previous value

Question

Sometimes I use marks to navigate easily through different files using mA, mB... and 'A, 'B...

And sometime (more often than I'd like to admit) because of inattention or whatever the reason is, I use m[LETTER] with an already existing mark which erase its previous value when I don't want to. Most of the time when I do that I don't have open the file originally pointed by the mark.

In this case when I immedialy realized that I made a mistake, is it possible to get the previous value of my mark other than remembering where it was pointing to, navigating to this location and setting it again?

I haven't found a command like that in the doc so if that doesn't exist is there a clever workaround that some of you use in this situation?

Answer 1

Here is some basic VimScript which roughly does what you want.

We override the ma through mz mappings to store the current value in g:previous_marks before calling the original m to actually set the mark. We also define <Leader>ma through <Leader>mz to show the history for said mark.

You will probably want to store the info in g:previous_marks in a more organized way, and add the ability to quickly restore a mark (rather than just seeing the locations), but this example shows how it can be done, further tweaks are left as an exercise to the reader ;-)

let g:previous_marks = {}
fun! MyMark(mark)
    let l:marks = ''
    redir => l:marks
        try
            silent! execute 'marks ' . a:mark
        catch
        endtry
    redir END

    if l:marks != ''
        if !has_key(g:previous_marks, a:mark)
            let g:previous_marks[a:mark] = []
        endif
        call add(g:previous_marks[a:mark], split(l:marks, "\n")[1])
    endif

    execute 'normal! m' . a:mark
endfun

fun! ShowHistory(mark)
    if !has_key(g:previous_marks, a:mark)
        echoerr 'No history for ' . a:mark
        return
    endif

    for l:line in g:previous_marks[a:mark]
        echo l:line
    endfor
endfun

fun! MakeMappings()
    for l:char in range(97, 122)
        let l:char = nr2char(l:char)

        execute 'nnoremap <silent> m' . l:char . ' :call MyMark("' . l:char . '")<CR>'
        execute 'nnoremap <silent> <Leader>m' . l:char . ' :call ShowHistory("' . l:char . '")<CR>'
    endfor
endfun

call MakeMappings()

Answer 2

Not exactly what you want, but perhaps more useful: the signature plugin. It shows the current marks as signs in the gutter margin, and has simple shortcuts for editing them. It can also put the list of signs in a location list for quick access.

Answer 3

Since the actual problem seems to be navigation between multiple files/positions, I'd suggest this simple solution, which is based on the Unite plugin:

:Unite jump -auto-preview

This command (which can be mapped to something like <leader>j for example) will show the jump list, with a preview: each time you navigate the list with j/k, several lines around the cursor position in that file will be displayed.

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Alternative:

The default marks are so easy to be overwritten: perhaps named bookmarks would better fit your use case, e.g. with the simple_bookmarks plugin.