[FEATURE] Allow to use a newline instead of padding

[cryptomilk]

Hi,

it would be great to have support to comment out code blocks in C using #if 0, like:

#if 0
/* main */
int main(void)
{
    return 0;
}
#endif

The reason is that also comment blocks can be commented out. Sadly the following doesn't work (yet):

ft.set('c', {'/*%s*/', '#if 0\n%s\n#endif'})

Thanks!

[numToStr]

To be honest, I won't be adding any special support for any specific language. And I don't think new lines in block comments would work like you showed. I tried the following and it worked for me.

ft.c = { '/*%s*/', '#if 0%s#endif' }
-- or
ft.set('c', { '/*%s*/', '#if 0%s#endif' })

If you need the desired result you should add an empty line above and below the code and then do the comments.

2021-10-16.20-34-24.mp4

[cryptomilk]

You don't have to support a special language, but allow to set it in the filetype config, like:

ft.set({
    lang = 'c',
    line = { '/*%s*/' },
    block = {
        comment =  '#if 0%s#endif',
        padding = false,
        newline = true,
 })

[numToStr]

I think you are mixing block comments with something else. And your use case is totally different and have nothing to do with comments. I hope you know that.

[cryptomilk]

In the end it comes down to insert a newline instead of some padding. It might be that you want that, that you have:

--[[
ft.set('c', { '/*%s*/', '#if 0%s#endif' })
ft.set('cpp', { '/*%s*/', '#if 0%s#endif' })
--]]

Currently you get:

--[[ ft.set('c', { '/*%s*/', '#if 0%s#endif' })
ft.set('cpp', { '/*%s*/', '#if 0%s#endif' }) --]]

[numToStr]

The problem with new lines is that the plugin is now responsible for adding and removing newlines. And honestly, I don't want to deal with newlines for now 😐 .

[numToStr]

To cover your original use case. I made some helpers for you. This is not perfect but it's the best I could do.

local Op = require('Comment.opfunc')
local U = require('Comment.utils')
local A = vim.api

local if_def = '#if 0%s#endif'

function _G.___comment_ifdef(vmode, uncomment)
    local srow, erow = U.get_region(vmode)

    if uncomment then
        A.nvim_buf_set_lines(0, srow - 1, srow, false, { '' })
        A.nvim_buf_set_lines(0, erow - 1, erow, false, { '' })
        return
    end

    local new_srow = srow - 1 -- moving one line upwords
    local new_erow1, new_erow2 = erow + 1, erow + 2 -- moving one line downwards

    A.nvim_buf_set_lines(0, new_srow, new_srow, false, { '' })
    A.nvim_buf_set_lines(0, new_erow1, new_erow1, false, { '' })

    local lines = {
        A.nvim_buf_get_lines(0, new_srow, srow, false)[1],
        A.nvim_buf_get_lines(0, new_erow1, new_erow2, false)[1],
    }

    local lcs, rcs = U.unwrap_cstr(if_def)

    Op.blockwise({
        cfg = { padding = true },
        cmode = U.cmode.comment,
        lcs = lcs,
        rcs = rcs,
        srow = srow,
        erow = new_erow2,
        lines = lines,
    })
end

local opts = { noremap = true, silent = true }

-- This is only for comment. Supports dot-repeat
-- Example: gla{ (comment around curly bracket)
A.nvim_set_keymap('n', 'gl', '<CMD>set operatorfunc=v:lua.___comment_ifdef<CR>g@', opts)

-- Comment/Uncomment in visual mode
A.nvim_set_keymap('x', 'gl', '<ESC><CMD>lua ___comment_ifdef(vim.fn.visualmode(), false)<CR>', opts)
A.nvim_set_keymap('x', 'gL', '<ESC><CMD>lua ___comment_ifdef(vim.fn.visualmode(), true)<CR>', opts)

[cryptomilk]

I've implemented it using a post hook now:

local A = vim.api
local C = require('Comment.config'):new()
local U = require('Comment.utils')
local ft = require('Comment.ft')

ft.set('c', {'/*%s*/', '#if 0%s#endif'})
ft.set('cpp', {'/*%s*/', '#if 0%s#endif'})

local post_hook = function(ctx)
    if vim.bo.filetype ~= 'c' and vim.bo.filetype ~= 'cpp' and vim.bo.filetype ~= 'lua' then
        return
    end

    if ctx.range.srow == -1 then
        return
    end

    if ctx.ctype == 1 then
        return
    end

    local cfg = C:get()
    local cstr = ft.get(vim.bo.filetype, ctx.ctype)
    local lcs, rcs = U.unwrap_cstr(cstr)
    local padding = U.get_padding(cfg.padding)
    local lines = A.nvim_buf_get_lines(0, ctx.range.srow - 1, ctx.range.erow, false)

    if ctx.cmode == 1 then
        -- comment
        local str = lines[1]
        local i, j = string.find(str, lcs .. padding)
        lines[1] = string.sub(str, i, j - #padding)
        table.insert(lines, 2, string.sub(str, 0, i - 1) .. string.sub(str, j + #padding, #str))

        str = lines[#lines]
        i, j = string.find(str, rcs)
        lines[#lines] = string.sub(str, 0, i - #padding - 1)
        table.insert(lines, #lines + 1, string.sub(str, i, j))
    elseif ctx.cmode == 2 then
        -- uncomment
        if #lines[1] == 0 and #lines[#lines] == 0 then
            table.remove(lines, 1)
            table.remove(lines, #lines)
        end
    end

    vim.api.nvim_buf_set_lines(0, ctx.range.srow - 1, ctx.range.erow, false, lines)
end

require('Comment').setup({
    post_hook = post_hook,
})

The result looks like:

#if 0
/* main */
int main(void)
{
    return 0;
}
#endif

[numToStr]

Just curious, Why do you need config in post_hook?

[cryptomilk]

I thought I need it to local lcs, rcs = U.parse_cstr(cfg, ctx), but after reading the functions, it isn't needed.

[numToStr]

There is also U.unwrap_cstr() that only deals with commentstring. You might wanna use that instead of U.parse_cstr()

[cryptomilk]

I already implemented that, see code above ;-)

[cryptomilk]

I need access the config to get cfg.padding.

[numToStr]

Just call the following to get the config

require('Comment').get_config()

[rr0gi]

seconding support for newlines (it is a personal preference matter ofc)
(thanks for the hook code but would be nice to have it builtin support \n in commentstring)