Short key mapping by lua for Neovim?

Question

The simple way to remap key in lua is:

vim.api.nvim_set_keymap('n', 'foo', 'bar', { noremap = true, silent = true })

But I want a simple syntax like vimScript: nnoremap foo bar

n_keymap('foo','bar')

How I can I write this function n_keymap ?

Answer 1

A simple way to do it is like this:

local n_keymap = function(lhs, rhs)
    vim.api.nvim_set_keymap('n', lhs, rhs, { noremap = true, silent = true })
end

n_keymap('foo','bar')

But in my opinion that doesn't make any sense because the map function are quite powerful (they support different modes, recursive or not, silent or not, expression mappings, buffer local mappings, etc...) so

1. At one point you will have to incorporate these features into you own function which is basically reinventing the wheel
2. You won't make the syntax easier or shorter than what already exists in vimscript while keeping it readable
3. You are creating something super custom that you are the only one to use, that you will need to maintain and which will most likely cost you more time in maintenance than if you'd use the built-in mechanisms.

So my recommendation would be: do use that.

Answer 2

I have found a slightly different solution here:

local function map(mode, lhs, rhs, opts)
local options = {noremap = true}
    if opts then options = vim.tbl_extend('force', options, opts) end
    vim.api.nvim_set_keymap(mode, lhs, rhs, options)
end

Bellow, you have some example mappings using the proposed function

-- <Tab> to navigate the completion menu
map('i', '<S-Tab>', 'pumvisible() ? "\\<C-p>" : "\\<Tab>"', {expr = true})
map('i', '<Tab>', 'pumvisible() ? "\\<C-n>" : "\\<Tab>"', {expr = true})

map('n', '<C-l>', '<cmd>noh<CR>')    -- clears highlights
map("i", "<s-cr>", "<c-o>o")         -- adds new line below (insert)
map("i", "<c-cr>", "<c-o>O")         -- adds new line above (insert)

-- It adds motions like 25j and 30k to the jump list, so you can cycle
-- through them with control-o and control-i.
-- source: https://www.vi-improved.org/vim-tips/
map("n", "j", [[v:count ? (v:count > 5 ? "m'" . v:count : '') . 'j' : 'gj']], { expr = true })
map("n", "k", [[v:count ? (v:count > 5 ? "m'" . v:count : '') . 'k' : 'gk']], { expr = true })

Answer 3

This is a bug. On vim this menu used to be horizontal. They made it vertical on neovim but they didn't change the controls. You can fix it like:

Lua

vim.api.nvim_set_keymap('c', '<Up>', 'wildmenumode() ? "<Left>" : "<Up>"', {expr = true, noremap=true})
vim.api.nvim_set_keymap('c', '<Down>', 'wildmenumode() ? "<Right>" : "<Down>"', {expr = true, noremap=true})
vim.api.nvim_set_keymap('c', '<Left>', 'wildmenumode() ? "<Up>" : "<Left>"', {expr = true, noremap=true})
vim.api.nvim_set_keymap('c', '<Right>', 'wildmenumode() ? "<Down>" : "<Right>"', {expr = true, noremap=true})

Vimscript alternative

cnoremap <expr> <Up> wildmenumode() ? '<Left>' : '<Up>'
cnoremap <expr> <Down> wildmenumode() ? '<Right>' : '<Down>'
cnoremap <expr> <Left> wildmenumode() ? '<Up>' : '<Left>'
cnoremap <expr> <Right> wildmenumode() ? '<Down>' : '<Right>'

See: https://github.com/neovim/neovim/issues/9953