I just realized that VIM 7.3 has built-in support for highlighting Markdown files. Excellent. However, it doesn't fold on the headings.
Can any offer suggestions on how to get this working?
Alternatively, I'm using Markdown only as a way to get simple structured text. If there is a better alternative format, please also suggest. But not sure I dig TVO or VimOutliner.
When I use markdown I only use the hash-style headings with space separating hashes and text. This makes the folding task a lot simpler.
I'm pretty new to Vim, so use the following at your own risk. I added the following code to my vimrc and it folds headings based on number of hashes, and it retains the syntax colouring.
function! MarkdownLevel()
if getline(v:lnum) =~ '^# .*$'
return ">1"
endif
if getline(v:lnum) =~ '^## .*$'
return ">2"
endif
if getline(v:lnum) =~ '^### .*$'
return ">3"
endif
if getline(v:lnum) =~ '^#### .*$'
return ">4"
endif
if getline(v:lnum) =~ '^##### .*$'
return ">5"
endif
if getline(v:lnum) =~ '^###### .*$'
return ">6"
endif
return "="
endfunction
au BufEnter *.md setlocal foldexpr=MarkdownLevel()
au BufEnter *.md setlocal foldmethod=expr
There is a vim-markdown plugin at https://github.com/plasticboy/vim-markdown .
The code related to folding from there appears to be:
" fold region for headings
syn region mkdHeaderFold
\ start="^\s*\z(#\+\)"
\ skip="^\s*\z1#\+"
\ end="^\(\s*#\)\@="
\ fold contains=TOP
" fold region for lists
syn region mkdListFold
\ start="^\z(\s*\)\*\z(\s*\)"
\ skip="^\z1 \z2\s*[^#]"
\ end="^\(.\)\@="
\ fold contains=TOP
syn sync fromstart
setlocal foldmethod=syntax
Working from @Omar comment to this answer, I coded a fold method to languages which comment with //, like JS. Add following to ~/.vimrc:
autocmd FileType javascript setlocal foldmethod=expr foldcolumn=6
autocmd FileType javascript setlocal foldexpr=JSFolds()
" Level of a folding:
"// #: level 1
"// ##: level 2
"// ###: level 3
function! JSFolds()
" Option 1: // and no space and hashes:
"if getline(v:lnum) =~ '^//#'
" Option 2: // and 1 space and hashes:
"if getline(v:lnum) =~ '^//\+ #'
" Option 3: spaces/tabs/nothing and // and 1 space and hashes:
if getline(v:lnum) =~ '^\s*//\+ #'
" Option 4: anything and // and 1 space and hashes:
" DANEGROUS! Potential conflict with code. E.g. print("// # Title");
" if getline(v:lnum) =~ '//\+ #'
" Number of hashs # in line that success previous condition (if)
" determine the fold level
let repeatHash = len(matchstr(getline(v:lnum), '#\+'))
return ">" . repeatHash
endif
return "="
endfunction
Examples. Note on the left the fold levels ("|" and "-"):
- // # ** Fold style recommended **
- // # 1 easy case
|- // ## 2 easy case
||- // ### 3 easy case
||| // Comment inside level 3
|||- // #### 4 easy case
|||| // Comment inside level 4
|- // ## 2 easy case (indents are OK with Option 3)
|| /#### error (JS comment needs 2 slashes)
||
- // # ** Fold of just 1 line **
|-- // ### 3 easy case
||- // ### = same fold level as previous line, thus previous line folds just itself ?!? (not concerns this fold function)
|||
- // # ** Space needed before, BUT not needed after hash/-es **
|- // ##Fold Level changed Because no space after hashes is OK: '// # ' vs '// #NoSpace'. NoSpace could even be a return carriage (enter).
|| //## Fold Level Unchanged Because no space after pair of slashes: '// #' vs '//#'
|| // ##txt Unchanged Because too much space after slashes
|| // ## txt Unchanged Because too much space after slashes
||
- // # ** Odds vs Even slashes **
- /// # 1 overrides typo 3 slash instead of just 2 (/// vs //)
- ///// # 1 overrides typo 5 slash instead of just 4 (///// vs ////). Read Recommenting Comments notes.
|- // ## ** As long as the pattern is at least '// # ', further previous slashes are ok **
- // # 1 easy case
|-- // ### 3 ok (and recommended fold style)
||- ///// ### 3 ok (recommented + typo)
||- ////// ### 3 ok (re-recommented)
||- /// ### 3 ok (typo)
||- //// ### 3 ok (recommented)
||- ///////// ### 3 ok (who cares? it works!)
|||
- // # ** Recommenting Comments **
- // # 1 easy case
| // Comment inside level 1
- //// # 1 recommented a comment
| //// Comment inside level 1
- ///// # 1 re-re-recomment
| ///// Comment inside level 1
|
- // # ** Recommenting Comments adding text **
|-- // ### //// # 3 changing fold level on purpose of a recommented a comment
||| // Comment inside level 3
||| // text // ## 2 (recommented a comment adding text)
||| // text#text // ## 2 right {recommented a comment adding initial text, as long as this text has no hash just after '// ' (2*slash + space) would be ok }
- // #text#text // ## 2 wrongly {recommented a comment adding initial text, as long as this text has no hash just after '// ' (2*slash + space) would be ok }
- // # changeFoldIntentionally // ## 1 clear intention to change fold level of comments
- // #changeFoldIntentionally // ## 1 clear intention to change fold level of comments (previousi example, with space after hash would be clearer)
|-- // ### changeFoldIntentionally // ## 3 clear intention to change fold level of comments
|||
PD: totally open to critics and improvements of the code. Actually I'm a beginner with vimscript.
Here's what I came up with as a combination of many of the other answers here. I found that most of them, including the builtin g:markdown_folding, do not properly handle code blocks that contain # characters as part of comments. I based this on matching the syntax IDs, which also handles <h1-6> tags properly.
" ~/.vim/ftplugin/markdown.vim
function MarkdownLevel(lnum)
for synID in synstack(a:lnum, 1)
let name = synIDattr(synID, "name")
if name == 'htmlH1' | return ">1"
elseif name == 'htmlH2' | return ">2"
elseif name == 'htmlH3' | return ">3"
elseif name == 'htmlH4' | return ">4"
elseif name == 'htmlH5' | return ">5"
elseif name == 'htmlH6' | return ">6"
endif
endfor
return "="
endfunction
setlocal foldexpr=MarkdownLevel(v:lnum)
setlocal foldmethod=expr
setlocal foldlevel=1