divider line comment

[chrisgrieser]

Not really using this plugin, but I created a function that adds a divider line comment (similar to an hr element in markdown). It uses commentstring to work in most languages, and also correctly considers textwidth and indentation.

I'd do a PR to add this, but tbh I haven't found the time yet to figure out Comments.nvim's code base 😅 (If anyone has some pointers, or wants to make a PR themselves, feel free to do so!)

function commentHr(opts)
	local fn = vim.fn
	local bo = vim.bo
	local append = vim.fn.append
	local setline = vim.fn.setline

	if not (opts) then opts = {linechar = "-"} end
	local linechar = opts.linechar
	local wasOnBlank = getline(".") == ""
	local indent = fn.indent(".")
	local textwidth = bo.textwidth
	local comStr = bo.commentstring
	local comStrLength = #(comStr:gsub("%%s", ""):gsub(" ", ""))

	if comStr == "" then
		vim.notify(" No commentstring for this filetype available.", vim.log.levels.WARN)
		return
	end
	if comStr:find("-") then linechar = "-" end

	local linelength = textwidth - indent - comStrLength
	local fullLine = string.rep(linechar, linelength)
	local hr = comStr:gsub(" ?%%s ?", fullLine)
	if bo.filetype == "markdown" then hr = "---" end

	local linesToAppend = {"", hr, ""}
	if wasOnBlank then linesToAppend = {hr, ""} end

	append(".", linesToAppend)

	-- shorten if it was on blank line, since fn.indent() does not return indent
	-- line would have if it has content
	if wasOnBlank then
		cmd [[normal! j==]] -- move down and indent
		local hrIndent = fn.indent(".")
		-- cannot use simply :sub, since it assumes one-byte-size chars
		local hrLine = getline(".") ---@type string
		hrLine = hrLine:gsub(linechar, "", hrIndent)
		setline(".", hrLine)
	else
		cmd [[normal! jj==]]
	end
end