How to map TSToggle to J and have the fallback be the original J?

[lfilho]

Hi!
My use case: I would like to use J as the keymap for toggling. But, if the plugin fails to join/split something, I'd like it to just execute vim's default J (just joining two lines regardless of its semantics, i.e. just removing the linebreak).

Is that possible and if so how to do it? Thanks!

[Wansmer]

Hi! You can to do this with the fallback option and pass as fallback vim.cmd.join() or vim.api.nvim_feedkeys('J', 'n', true).
How to create fallback:

1. How to use `fallback` option #126
2. Fallback to mini.splitjoin #143 (comment)

[lfilho]

Hi @Wansmer thanks for your answer. I did see those before posting, but I still couldn't figure out how to apply to my case. Different from those, I don't want that to a particular language or conditional to Treesitter existing or not. As a matter of fact, what i was trying to accomplish is on a regular language with treesitter working in it (javascript).

What I would like is:

1. invoke TSToggle as usual on my javascript file
2. It will try to do its thing
3. If it fails (no action from TSToggle), then call vim.cmd.join()

Hope that's clearer. Would you be able to guide me how to accomplish that? Thank you

[Wansmer]

The solution will be the same as here. You just have to loop through each node (not just comment as in the example) in each language and add a fallback function with vim.cmd.join().

Second solution, add a function to the error handler (opts.on_error) and call join in it. You can see the possible error texts in the file lua/treesj/notify.lua. However, this is a less predictable solution than the above option.

[lfilho]

I see, thanks. I'm not too familiar with lua nor the inner workings of your script.

Is this what it would look like?

    "Wansmer/treesj",
    keys = { { "J", "<cmd>TSJToggle<CR>", desc = "Split/Join" } },
    dependencies = { "nvim-treesitter/nvim-treesitter" },
    config = function()
      local langs = require("treesj.langs").presets

      -- Add fallback to all language
      for _, nodes in pairs(langs) do
        -- print nodes:

        for _, node in ipairs(nodes) do
          node.fallback = function()
            vim.cmd.join()
          end
        end
      end

      require("treesj").setup()
    end,
  },

It unfortunately didn't work. See screenshot below: i was just trying to get line 330 up (regular J). But TreeSJ just showed that notification, without actually calling vim.cmd.join(). Another weird things is the notification itself: it mentions containing a comment but as you can see in the screenshot, there isn't a comment in the code?!

Any clues? Thanks again

[Wansmer]

There's nothing wrong with your code. I guess I was wrong to advise you on this, sorry. Do this:

require("treesj").setup({
  on_error = function()
    vim.cmd.join()
  end,
})

vim.keymap.set("n", "J", require("treesj").join)

This will do what you want in all cases where treesj gets an error that for some reason it can't do join for a node.

2024-05-17.21.04.55.mov

it mentions containing a comment but as you can see in the screenshot, there isn't a comment in the code?!

Read how the plugin works.

The nearest matching node has a comment

[lfilho]

Ah that seems to work!! Thank you!!! <3