Compact C Folding in Vim - c

Question

I'm trying to make a simple Vim script that would create very compact top-level folds for c files. Ideally, if it was run on this code:
static void funca(...)
{
...
}
/* Example comment */
static void funcb(...)
{
...
}
Then it would create folds which would look like this when closed:
+-- x Lines: static void funca(...)----------------------
+-- x Lines: static void funcb(...)----------------------
So basically it would be like foldmethod=syntax with foldlevel=1, except that each fold would start one line further up, and would extend further down to include all following blank lines.
I know how to make one of these folds (assuming foldmethod=manual):
/^{<cr>kVnn?^$<cr>zf
But I'm not sure how to put it into a function. This is my effort:
function Cfold()
set foldmethod=manual " Manual folds
ggzE " Delete all folds
while (/^{<cr>) " Somehow loop through each match
kVnn?^$<cr>zf " This would work fine except for the last function
endwhile
endfunction
map <Leader>f :call Cfold()<cr>
But it isn't valid, I'm not entirely sure how functions work. Also, it won't work for the last function in the file, since it won't find '^{' again. If someone could help me get this working, and somehow add a case for the last function in a file, I would be extremely grateful.
Thanks in advance :)

Answer 1

You can create folds programmatically using the foldexpr and foldtext. Try this, though you may have to tweak CFoldLevel so it doesn't swallow non-function parts of the code:
function! CFoldLevel(lnum)
let line = getline(a:lnum)
if line =~ '^/\*'
return '>1' " A new fold of level 1 starts here.
else
return '1' " This line has a foldlevel of 1.
endif
endfunction
function! CFoldText()
" Look through all of the folded text for the function signature.
let signature = ''
let i = v:foldstart
while signature == '' && i < v:foldend
let line = getline(i)
if line =~ '\w\+(.*)$'
let signature = line
endif
let i = i + 1
endwhile
" Return what the fold should show when folded.
return '+-- ' . (v:foldend - v:foldstart) . ' Lines: ' . signature . ' '
endfunction
function! CFold()
set foldenable
set foldlevel=0
set foldmethod=expr
set foldexpr=CFoldLevel(v:lnum)
set foldtext=CFoldText()
set foldnestmax=1
endfunction
See :help 'foldexpr' for more details.