How to retain i_CTRL+p i_CTRL+n and use them to select a completion option

[cskeeters]

I just wanted to share two options that allow a user to use this plugin and keep the builtin i_CTRL+p and i_CTRL+n (which I can't live without) and doesn't resort to the arrow keys.

Considering I often want to retype keywords or variable names that are close to the cursor, I find the old functionality provided by i_CTRL+p and sometimes i_CTRL+n more useful for producing code quickly than LSP assisted autocompletion, especially when I'm familiar with the code base. It's like a CPU L1 cache hit as what you're looking for is likely on the previous line. It's the fastest because you typically only need to type one or two letters before triggering the completion accurately and little to no visual scanning is involved. However, LSP assisted autocompletion is cool and useful when you're referencing functions in other files, or language builtins when your working in a language your not used to. Turns out you can and I will document two ways that I like.

One way to do this is by using the super-tab preset and removing the <C-p> and <C-n> key bindings. Also, if my cursor is at the end of the bottom of the screen, I don't like it when the menu covers the text in the lines above it as that henders my ability to scan quickly to determine the number of characters I may need to type before triggering i_CTRL+p. This does both.

return {
    'saghen/blink.cmp',
    opts = {
        keymap = {
            preset = 'super-tab',

            ['<C-n>'] = false,
            ['<C-p>'] = false,
        },

        completion = {
            -- Ok to show documentation as we're committing to having other text blocked
            documentation = { auto_show = true }

            menu = {
                -- Don't automatically show the completion menu
                auto_show = false,
            },

            ghost_text = { enabled = true },
        },

        signature = { enabled = true },
    },
}

Note

This is not a complete working config. It's only a skeleton to show the relevant options.

Trying this, it doesn't strike me as that bad. <C-e><Tab> can be used to input indentation. However, according to @tjdevries "you are wrong to use anything other than the default" 😄. So I have this other solution that uses the default preset.

-- Function to handle both blink.cmp and default <C-n> behavior
function C_n_handler()
    local blink = require('blink.cmp')
    if blink.is_menu_visible() then
        blink.select_next()
    else
        vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<C-n>", true, true, true), "n", true)
    end
end

-- Function to handle both blink.cmp and default <C-p> behavior
function C_p_handler()
    local blink = require('blink.cmp')
    if blink.is_menu_visible() then
        blink.select_prev()
    else
        vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<C-p>", true, true, true), "n", true)
    end
end

return {
    'saghen/blink.cmp',
    opts = {
        keymap = {
            preset = 'default',

            ['<C-n>'] = false,
            ['<C-p>'] = false,
        },

        completion = {
            -- Ok to show documentation as we're committing to having other text blocked
            documentation = { auto_show = true }

            menu = {
                -- Don't automatically show the completion menu
                auto_show = false,
            },

            ghost_text = { enabled = true },
        },

        signature = { enabled = true },
    },

    init = function()
        vim.keymap.set("i", "<C-n>", C_n_handler, { noremap = true, silent = true })
        vim.keymap.set("i", "<C-p>", C_p_handler, { noremap = true, silent = true })
    end,
}

It hides the popup menu by default, which keeps the hover window out of the way if you're glancing to look at what variables might conflict with standard i_CTRL+p which I like, and it enables ghost_text which is good enough for some cases and lets me know that there are options to view. Without the menu open, i_CTRL+p and i_CTRL+n work normally. Once you hit <C-Space>, the menu opens and <C-n> and <C-p> change the selection in the menu.