function map(mode, lhs, rhs, opts)
    local options = { noremap = true, silent = true }
    if opts then
        options = vim.tbl_extend("force", options, opts)
    end
    vim.keymap.set(mode, lhs, rhs, options)
end
--This code just maps vim.keymap.set() to something easier to type. Also, typing { noremap = true, silent = true } won’t be needed, because that is also implemented in the function.

vim.g.mapleader = " "

map("n", "<leader>+", ":bNext<cr>") --switch tabs
map("n", "<leader>n", ":Neotree toggle<cr>") --open Nerdtree
map("n", "<leader>z", ":ZenMode<cr>") --open ZenMode (distraction-free)
map("n", "<leader>d", ":ToggleDiag<cr>") -- toggle all diagnostics




vim.api.nvim_create_autocmd('LspAttach', {
  desc = 'LSP actions',
  callback = function()
    local bufmap = function(mode, lhs, rhs)
      local opts = {buffer = true}
      vim.keymap.set(mode, lhs, rhs, opts)
    end

    -- Displays hover information about the symbol under the cursor
    bufmap('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>')

    -- Jump to the definition
    bufmap('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>')

    -- Jump to declaration
    bufmap('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>')

    -- Lists all the implementations for the symbol under the cursor
    bufmap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>')

    -- Jumps to the definition of the type symbol
    bufmap('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>')

    -- Lists all the references 
    bufmap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>')

    -- Displays a function's signature information
    bufmap('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>')

    -- Renames all references to the symbol under the cursor
    bufmap('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>')

    -- Selects a code action available at the current cursor position
    bufmap('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>')

    -- Show diagnostics in a floating window
    bufmap('n', 'gl', '<cmd>lua vim.diagnostic.open_float()<cr>')

    -- Move to the previous diagnostic
    bufmap('n', '[d', '<cmd>lua vim.diagnostic.goto_prev()<cr>')

    -- Move to the next diagnostic
    bufmap('n', ']d', '<cmd>lua vim.diagnostic.goto_next()<cr>')
  end
})