nvim: Extend lsp for nvim lua development

Added new functionality to lsp: hovering, go-to definition, referencing,
implementations, etc accessible through the usual hotkeys.

Added commands to invoke LspHover and temporarily disable lsp for the
current buffer (is re-enabled on re-entering the buffer, e.g. with
:e<cr>)

Added tjdevries extended lua lsp implementation containing functionality
for the nvim api itself (especially useful for `vim.api`, `vim.fn`).

nvim/.config/nvim/init.vim

@@ -80,6 +80,8 @@ Plug 'reedes/vim-textobj-sentence'
 Plug 'junegunn/goyo.vim', { 'for': ['pandoc', 'markdown', 'txt'], 'on': 'Goyo' }      " provide distraction free writing
 Plug 'junegunn/limelight.vim', { 'for': ['pandoc', 'markdown', 'txt'], 'on': 'Goyo' } " provide even distraction free-er writing (lowlight paragraphs)
                                                                                       " Language Integration
+Plug 'tjdevries/nlua.nvim'                                                            " lua lsp integration
+Plug 'euclidianAce/BetterLua.vim'                                                     " better syntax highlighting for lua
 Plug 'sheerun/vim-polyglot'                                                           " syntax plugins for almost every language
 Plug 'stephpy/vim-yaml'
 Plug 'mhartington/nvim-typescript', {'for': 'typescript','do': './install.sh'}

nvim/.config/nvim/lua/nvim-lspconfig/init.lua

@@ -0,0 +1,31 @@
+
+local on_attach = function(client, bufnr)
+  -- Keybindings for LSPs
+  -- Note these are in on_attach so that they don't override bindings in a non-LSP setting
+  vim.fn.nvim_set_keymap("n", "gd", "<cmd>lua vim.lsp.buf.definition()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "gD", "<cmd>lua vim.lsp.buf.implementation()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "K", "<cmd>lua vim.lsp.buf.hover()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "<c-k>", "<cmd>lua vim.lsp.buf.signature_help()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "1gD", "<cmd>lua vim.lsp.buf.type_definition()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "gr", "<cmd>lua vim.lsp.buf.references()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "g0", "<cmd>lua vim.lsp.buf.document_symbol()<CR>", {noremap = true, silent = true})
+  vim.fn.nvim_set_keymap("n", "gW", "<cmd>lua vim.lsp.buf.workspace_symbol()<CR>", {noremap = true, silent = true})
+end
+
+require'nvim_lsp'.pyls.setup{on_attach=on_attach}
+require'nvim_lsp'.vimls.setup{on_attach=on_attach}
+require'nvim_lsp'.bashls.setup{on_attach=on_attach}
+require'nvim_lsp'.gopls.setup{on_attach=on_attach}
+require'nvim_lsp'.texlab.setup{on_attach=on_attach}
+
+-- To get builtin LSP running, do something like:
+-- NOTE: This replaces the calls where you would have before done `require('nvim_lsp').sumneko_lua.setup()`
+require('nlua.lsp.nvim').setup(require('nvim_lsp'), {
+  on_attach = on_attach,
+
+  -- Include globals you want to tell the LSP are real :)
+  globals = {
+    -- Colorbuddy
+    "Color", "c", "Group", "g", "s",
+  }
+})

nvim/.config/nvim/plugin/nvim-lspconfig.vim

@@ -1,12 +1,6 @@
-lua << END
+command! LspHover lua vim.lsp.buf.hover()<CR>
+command! LspDisable lua vim.lsp.stop_client(vim.lsp.get_active_clients())<CR>
 
-require'nvim_lsp'.pyls.setup{}
-require'nvim_lsp'.vimls.setup{}
-require'nvim_lsp'.bashls.setup{}
-require'nvim_lsp'.gopls.setup{}
-require'nvim_lsp'.texlab.setup{}
-
--- requires manual `:LspInstall sumneko_lua`
-require'nvim_lsp'.sumneko_lua.setup{}
-
-END
+" actual LSP config takes place in lua ('lua/lsp')
+lua require("nvim-lspconfig")
+setlocal omnifunc=v:lua.vim.lsp.omnifunc