Can't use // line comments in C

[realh]

I want to use // for my C comments, but the plugin seems to be hardwired to use /* */ for C. This config has no effect:

local ft = require('Comment.ft')

ft.c = {'//%s', '//%s'}

[sharpchen]

should use get and set instead

require('Comment.ft').set('c', {'//%s', '//%s'})

And I don't think this make any sense? the second element is for block commenting, you can never use // to do that because that uses a different string format.
Simply use gc to do line commenting for each line you selected.

[realh]

I got it working with this:

vim.api.nvim_create_autocmd('Filetype', {
  pattern = 'c',
  callback = function()
		vim.bo.commentstring = '//%s'
  end,
  group = comment_augroup
})

Does Comment.ft get ignored for filetypes which have a commentstring?

[sharpchen]

vim.bo.commentstring is the last resort, pre_hook and ft has higher priority

Comment.nvim/lua/Comment/utils.lua

Lines 173 to 185 in e30b7f2

	function U.parse_cstr(cfg, ctx)
	-- 1. We ask `pre_hook` for a commentstring
	local inbuilt = U.is_fn(cfg.pre_hook, ctx)
	-- 2. Calculate w/ the help of treesitter
	or F.calculate(ctx)
	assert(inbuilt or (ctx.ctype ~= U.ctype.blockwise), {
	msg = vim.bo.filetype .. " doesn't support block comments!",
	})
	-- 3. Last resort to use native commentstring
	return U.unwrap_cstr(inbuilt or vim.bo.commentstring)
	end

[realh]

ft.set works, thanks. I thought I could assign to ft.c because of the examples for javascript and yaml in README.md, where it says "Metatable magic". Are those examples wrong? If not, why does that syntax work for yaml and javascript, but not c?

[sharpchen]

I never noticed that usage, it actually should work since it uses set too.

Comment.nvim/lua/Comment/ft.lua

Lines 310 to 314 in e30b7f2

	---@export ft
	return setmetatable(ft, {
	__newindex = function(this, k, v)
	this.set(k, v)
	end,

But it's set only, you can't get the value with the same form.

[A-caibird]

you can use a plug: https://github.com/JoosepAlviste/nvim-ts-context-commentstring/wiki/Integrations#commentnvim