Feature: Add "duplicate" (yank, comment, paste) function?

[garymh]

Would it be possible to add in a motion for "duplicating" text? I often (hopefully I'm not the only one) will yank and paste and a line/paragraph of code and then comment out the original so I can look at it for reference while I rework it. For example:

def cool_function(hello)
	puts hello
end

Typing something like gcd{motion} (ip here for a paragraph) would give us:

# def cool_function(hello)
# 	puts hello
# end

def cool_function(hello)
	puts hello
end

This was suggested as a feature with vim-commentary but I think it's still being discussed/considered: tpope/vim-commentary#42

It would be neat to see here too 😃

Love the plugin, btw!

[numToStr]

To be clear I won't support this inside the plugin. Currently, I am working on #62 which will give you the selected region in the pre_hook as an argument and you can use pre_hook in a way that is similar to your use case.

I am just dumping my brain here and assuming that the PR is merged. IMO following will be steps

1. Get the text using the provided range
2. Add the grabbed text below the original text
3. The plugin will comment the original text

What do you say?

[garymh]

@numToStr Sounds great! I appreciate it!

[numToStr]

For future somebody, this is what you'll need

require('Comment').setup({
    pre_hook = function(ctx)
        local lines = require('Comment.utils').get_lines(ctx.range)
        local srow = ctx.range.erow
        vim.api.nvim_buf_set_lines(0, srow, srow, false, lines)
    end,
    post_hook = function(ctx)
        local U = require('Comment.utils')
        local srow = ctx.range.erow
        local erow = srow + 1
        local line = U.get_lines({ srow = srow, erow = erow })
        local _, col = U.grab_indent(line[1])
        vim.api.nvim_win_set_cursor(0, { erow, col })
    end,
})

NOTE: The only downside is this duplication will happen every time. But you can determine when to do this by using ctx argument

[garymh]

Hi @numToStr ! Has this changed recently because of the API? It seems to have stopped working...

[numToStr]

@garymh Yes, because of the recent (breaking) changes I made to the lua APIs. Following is the updated version:

local U = require("Comment.utils")
local A = require("Comment.api")

function _G.___gdc(vmode)
	local range = U.get_region(vmode)
	local lines = U.get_lines(range)

	-- Copying the block
	local srow = range.erow
	vim.api.nvim_buf_set_lines(0, srow, srow, false, lines)

	-- Doing the comment
	A.comment_linewise_op(vmode)

	-- Move the cursor
	local erow = srow + 1
	local line = U.get_lines({ srow = srow, erow = erow })
	local _, col = U.grab_indent(line[1])
	vim.api.nvim_win_set_cursor(0, { erow, col })
end

[garymh]

Awesome!! Thank you so much!!

[paopaol]

how do i use the function ___gdc, :lua _G.__gdc('n') ?

[numToStr]

@paopaol See #73 (comment)

[garymh]

Hello! It looks like the new refactor broke this function...

E5108: Error executing lua ...ite/pack/packer/start/Comment.nvim/lua/Comment/utils.lua:63: attempt to get length of local 'iter' (a nil
 value)                                                                                                                                
stack traceback:                                                                                                                       
        ...ite/pack/packer/start/Comment.nvim/lua/Comment/utils.lua:63: in function 'is_empty'                                         
        ...ite/pack/packer/start/Comment.nvim/lua/Comment/utils.lua:305: in function 'uncomment'                                       
        ...te/pack/packer/start/Comment.nvim/lua/Comment/opfunc.lua:135: in function 'linewise'                                        
        ...te/pack/packer/start/Comment.nvim/lua/Comment/opfunc.lua:76: in function 'opfunc'                                           
        .../site/pack/packer/start/Comment.nvim/lua/Comment/api.lua:152: in function 'comment_linewise_op'                             
        /Users/gary/.config/nvim/lua/config/comment.lua:22: in function </Users/gary/.config/nvim/lua/config/comment.lua:12>    

Should I just stick to 0.6.1? I'm afraid my Lua isn't good enough to fix it 😞

[numToStr]

@garymh This should do it

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

function _G.___gdc(motion)
    local range = U.get_region(motion)
    local lines = U.get_lines(range)

    -- Copying the block
    local srow = range.erow
    vim.api.nvim_buf_set_lines(0, srow, srow, false, lines)

    -- Doing the comment
    A.comment_linewise_op(motion)

    -- After #183 you might wanna use
    -- A.comment.linewise(motion)

    -- Move the cursor
    local erow = srow + 1
    local line = U.get_lines({ srow = srow, erow = erow })
    local col = U.indent_len(line[1])
    vim.api.nvim_win_set_cursor(0, { erow, col })
end

(Also make sure to update the plugin, as I discovered a bug while testing this function)

[garymh]

Perfect! Thank you so much, again! 😄