[ Discussion ] Is there any ways can make completion window auto popup without press `<C-n>` in InsertMode?

1 
api.nvim_create_autocmd("TextChangedI", {
    pattern = "*",
    callback = function ()
            local cursor_left = utils.get_cursor_content(-1, -1)
            if vim.fn.pumvisible() == 0 and cursor_left:match("%a") then
                api.nvim_input("<C-n>")
            end
    end
})

this snippets can auto popup completion window but in some case it seems will cause infinity loop such as input lua| <------ Cursor stay here :frowning:

local key_str = "a:b:c:d:e:f:g:h:i:j:k:l:m:n:o:p:q:r:s:t:u:v:w:x:y:z:_:-"

for key in string.gmatch(key_str, "[^:]") do
    vim.keymap.set("i", key, function ()
        if vim.fn.pumvisible() == 0 then
            return key .. "<C-n>"
        end
        return key
    end, { expr = true })
end

this implementation wont get any bad performance issue but it’s not that elegant :smiley_cat:

is there any cool way can implement that?