Showing hierarchy of nested closed folds in Vim

Question

I have 3 levels of folds in my file, all of which are created using {{{ }}}, i.e.:

"Fold 1{{{
Fold level 1 text
"Fold2 {{{
Fold level 2 text
"}}}
"}}}

I would like to see the hierarchy of closed folds in Vim, i.e.:

+-- 1 Line: Fold 1
+---- 1 Line: Fold 2 " this could be indented

Is that possible?

Answer 1

No. As Fold2 is contained within Fold1, the entire outer Fold1 will be collapsed to a single line. You could only write a custom 'foldtext' expression that checks for contained folds, and put that information into the single summary line. (I'm not sure whether such an expression might take up too much performance by going through all contained folds.)

To get an overview of folds, I usually close all folds via zM, and then repetitively open levels via zr.

Answer 2

Ingo is right that it cannot be done inside the current buffer. But you can achieve it as a print in another buffer or in the output command buffer. The following command gets all folding lines without the body texts in between :

:g/{{{/

It works for your example below (that contains a nested fold) with foldmethod=marker and default ({{{) mark :

"Fold 1{{{
Fold level 1 text
"Fold2 {{{
Fold level 2 text
"}}}
"}}}

After you run the :g/{{{/ command, you get this :

"Fold 1{{{
"Fold2 {{{

If you want to redirect the result to a new buffer, then you can run :

:let @a='' | execute 'g/{{{/y A' | new | setlocal bt=nofile | put! a

It yanks the {{{ pattern to register "a", opens a new buffer and pastes the reg. You may then need to expand the result with zR if your default is 'collapse folds'.

Please see this other answer with a bigger sample text.