Formatting of folds

Question

Is it possible to 'fold at the proper indentation' ? For example, the point in the below is to see conditional flow:

However, with how the above is formatted, it's almost impossible to see visually that those 42 lines are part of the else statement. Is it possible to do something like this in vim, or not really?

Answer 1

It's possible indeed!

As @Biggybi mentioned, you have to use foldtext to achieve that.

You assign a function to foldtext, and within this function, you can access the v:foldstart and v:foldend variables.

From there, you can access the indentation. Here's a simple example:

    function! NeatFoldText()
        let lines_count      = v:foldend - v:foldstart + 1
        return repeat(' ', indent(nextnonblank(v:foldstart))) . lines_count . ' lines '
    endfunction

    set foldtext=NeatFoldText()

---

If you want to have something a bit more advanced, here's what I have in my vimrc:

    function! NeatFoldText()
        let foldchar         = matchstr(&fillchars, 'fold:\zs.')
        let lines_count      = v:foldend - v:foldstart + 1
        let lines_count_text = printf("┈─ %1s lines ─┈", lines_count) . repeat(foldchar, 10)
        let foldtextstart    = repeat(' ', indent(nextnonblank(v:foldstart))) . " ••• " 
        let foldtextend      = lines_count_text . repeat(foldchar, 8)
        let foldtextlength   = strlen(substitute(foldtextstart . foldtextend, '.', 'x', 'g')) + &foldcolumn

        return foldtextstart . repeat(foldchar, winwidth(0) - foldtextlength) . foldtextend
    endfunction