My first delve into vimscript was writing a plugin for folding markdown lists.
I reckon there are a few idioms I'm missing here, so I would greatly appreciate any comments to improve the plugin.
I've noticed something akin to "header guards" in C family languages among popular plugins:
if exists('g:touchdown__loaded') finish endif " ... plugin body goes here ..." let g:touchdown__loaded=1
Logic for folding markdown lists is handled in the next chunk:
function! IndentLevel(lnum) return indent(a:lnum) / &shiftwidth endfunction function! NextNonBlankLine(lnum) let numlines = line('$') let current = a:lnum + 1 while current <= numlines if getline(current) =~? '\v\S' return current endif let current += 1 endwhile return -2 endfunction function! GetListFold(lnum) if getline(a:lnum) =~? '\v^\s*$' return '-1' endif let this_indent = IndentLevel(a:lnum) let next_indent = IndentLevel(NextNonBlankLine(a:lnum)) if next_indent == this_indent return this_indent elseif next_indent < this_indent return this_indent elseif next_indent > this_indent return '>' . next_indent endif endfunction
I've also set up a custom text for the lists, but I want to make sure my logic doesn't apply to folds that aren't markdown lists. Calling
foldtext when the regex doesn't match is the closest thing I know to do:
function! GetFoldText() if (match(getline(v:foldstart), "[\s\t]*[-\*][\s\t]*.*") != -1) let nl = v:foldend - v:foldstart let linetext = substitute(getline(v:foldstart),"-","+",1) let txt = linetext . "\t (" . nl . ' lines hidden)' else let txt = foldtext() endif return txt endfunction
Finally I apply the fold strategy here. One thing to note is I want this to only apply to markdown files, but I'm not sure how to accomplish that idiomatically:
setlocal foldtext=GetFoldText() setlocal foldmethod=expr setlocal foldexpr=GetListFold(v:lnum) setlocal fillchars=fold:\