<Tab> keymap fallback behavior sync with <C-i>

[b1nhack]

Make sure you have done the following

• Updated to the latest version of blink.cmp
• Searched for existing issues and documentation (try <C-k> on https://cmp.saghen.dev)

Bug Description

I map: vim.keymap.set('i', '<C-i>', '<Esc>A')

In blink.cmp:

keymap = {
      preset = 'none',
      ['<Tab>'] = { 'snippet_forward', 'fallback' },
    },

In i mode, <Tab> behavior is <Esc>A

Relevant configuration

neovim version

NVIM v0.11.1

blink.cmp version

main, cb5e346

[Saghen]

Can you provide a repro.lua for this?

[b1nhack]

repro.lua

-- Run with `nvim -u repro.lua`

vim.keymap.set("i", "<C-i>", "<Esc>A")

vim.env.LAZY_STDPATH = ".repro"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

---@diagnostic disable-next-line: missing-fields
require("lazy.minit").repro({
	spec = {
		{
			"saghen/blink.cmp",
			-- please test on `main` if possible
			-- otherwise, remove this line and set `version = '*'`
			build = "cargo build --release",
			opts = {
				keymap = {
					preset = "none",
					["<Tab>"] = { "snippet_forward", "fallback" },
				},
			},
		},
		{
			"neovim/nvim-lspconfig",
			opts = {
				servers = {
					lua_ls = {},
				},
			},
			config = function(_, opts)
				local lspconfig = require("lspconfig")
				for server, config in pairs(opts.servers) do
					-- passing config.capabilities to blink.cmp merges with the capabilities in your
					-- `opts[server].capabilities, if you've defined it
					config.capabilities = require("blink.cmp").get_lsp_capabilities()
					lspconfig[server].setup(config)
				end
			end,
		},
	},
})

[drowning-cat]

What terminal you're using. Are you using tmux?

[b1nhack]

No. Just kitty.

[drowning-cat]

NVIM v0.12.0-dev-261+g6577d72d81

C-i.mp4

[drowning-cat]

Okay, looks like it's a bug of a certain version of neovim if I understand your problem correctly.

[b1nhack]

I think it's may cause by #487. Neovim can Distinguishing between <Tab> and <C-i>. But blink.cmp keymap has this issue when keymap fallback. So, maybe something wrong about fallback.

keymap = {
      preset = 'none',
      ['<Tab>'] = { 'snippet_forward', 'fallback' },
    },

[drowning-cat]

To make sure we're on the same page: the behavior in the video is expected. I tried installing neovim v0.11.1 from the official Arch repository, and it behaves exactly like in the video when using the kitty terminal.

In your case, when you use <Tab> for a function~ autocomplete, it always triggers the <C-i> action (C-i inserted) instead of jumping to the next position, right?

[b1nhack]

I don't understand. If I use <Tab> in blink.cmp keymap settings. Anytime I type <Tab> I just want type <C-i>. So I can't Type TAB in editor.

v.mov

When I Don't use <Tab> in blink.cmp keymap settings, everything is ok.

v.mov

[Saghen]

Seems like this might be out of our control: https://www.reddit.com/r/neovim/comments/u24o3m/how_to_make_ctrli_work_in_neovim/

local normalize = function(key) return vim.api.nvim_replace_termcodes(key, true, true, true) end

normalize('<Tab>') == normalize('<C-i>') == '\t'

See :h <Tab> Adding a mapping for <Tab> seems to be enough to override the behavior on terminals that support it: vim.keymap.set("i", "<Tab>", "<Tab>")

If anyone knows of a solution that would allow blink.cmp to differentiate the keymaps without this workaround, please do tell!

[drowning-cat]

Silly question from me, will this work?

vim.api.nvim_replace_termcodes(key, true, true, false)

[Saghen]

It's possible that could work but I imagine there would be caveats. If you want to play around with it, the relevant code is: https://github.com/Saghen/blink.cmp/blob/main/lua/blink/cmp/keymap/fallback.lua#L19