Add cmp for completion support, luasnip for snippets and better syntax highlighting using treesitter

init.lua

@@ -3,7 +3,10 @@ require 'plugins'
 vim.cmd('colorscheme space-vim-dark')
 
 require 'lsp'
+require 'completion'
+require 'treesitter'
 require 'debugger'
 require 'term'
 require 'settings'
 require 'keys'
+

lua/completion.lua

@@ -0,0 +1,44 @@
+local luasnip = require 'luasnip'
+local cmp = require 'cmp'
+
+cmp.setup {
+  snippet = {
+    expand = function(args)
+      require('luasnip').lsp_expand(args.body)
+    end,
+  },
+  mapping = {
+    ['<C-p>'] = cmp.mapping.select_prev_item(),
+    ['<C-n>'] = cmp.mapping.select_next_item(),
+    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
+    ['<C-f>'] = cmp.mapping.scroll_docs(4),
+    ['<C-Space>'] = cmp.mapping.complete(),
+    ['<C-e>'] = cmp.mapping.close(),
+    ['<CR>'] = cmp.mapping.confirm {
+      behavior = cmp.ConfirmBehavior.Replace,
+      select = true,
+    },
+    ['<Tab>'] = function(fallback)
+      if vim.fn.pumvisible() == 1 then
+        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-n>', true, true, true), 'n')
+      elseif luasnip.expand_or_jumpable() then
+        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<Plug>luasnip-expand-or-jump', true, true, true), '')
+      else
+        fallback()
+      end
+    end,
+    ['<S-Tab>'] = function(fallback)
+      if vim.fn.pumvisible() == 1 then
+        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<C-p>', true, true, true), 'n')
+      elseif luasnip.jumpable(-1) then
+        vim.fn.feedkeys(vim.api.nvim_replace_termcodes('<Plug>luasnip-jump-prev', true, true, true), '')
+      else
+        fallback()
+      end
+    end,
+  },
+  sources = {
+    { name = 'nvim_lsp' },
+    { name = 'luasnip' },
+  },
+}

lua/keys.lua

@@ -9,3 +9,15 @@ key('', '<C-n>', ':NERDTreeToggle<CR>', {})
 
 key('i', '<TAB>', 'pumvisible() ? "<C-n>" : "<Tab>"', {expr = true, silent = true})
 key('i', '<S-TAB>', 'pumvisible() ? "<C-p>" : "<S-Tab>"', {expr = true, silent = true})
+
+-- Highlight on yank
+vim.api.nvim_exec(
+  [[
+  augroup YankHighlight
+    autocmd!
+    autocmd TextYankPost * silent! lua vim.highlight.on_yank()
+  augroup end
+]],
+  false
+)
+

lua/lsp.lua

@@ -23,7 +23,7 @@ local on_attach = function(client, bufnr)
   buf_set_keymap('n', 'ff',    ':lua vim.lsp.buf.formatting()<CR>',       opts)
   buf_set_keymap('n', 'gn', '<cmd>lua vim.lsp.buf.rename()<CR>', opts)
 
-  require'completion'.on_attach(client)
+  --require'completion'.on_attach(client)
 
   -- Set highlight colors
   local highlights = {
@@ -49,11 +49,16 @@ local on_attach = function(client, bufnr)
   )
 end
 
+-- nvim-cmp supports additional completion capabilities
+local capabilities = vim.lsp.protocol.make_client_capabilities()
+capabilities = require('cmp_nvim_lsp').update_capabilities(capabilities)
+
 
 local servers = require'lspinstall'.installed_servers()
 for _, lsp in ipairs(servers) do
   local config = {
     on_attach = on_attach,
+    capabilities = capabilities,
     flags = {debounce_text_changes = 150}
   }
   if lsp == "lua" then
@@ -61,3 +66,9 @@ for _, lsp in ipairs(servers) do
   end
   nvim_lsp[lsp].setup(config)
 end
+
+
+-- Set completeopt to have a better completion experience
+vim.o.completeopt = 'menuone,noselect'
+
+

lua/plugins.lua

@@ -31,6 +31,11 @@ return require('packer').startup({function()
   use 'nvim-lua/completion-nvim'
   use 'nvim-lua/popup.nvim'
   use 'nvim-lua/plenary.nvim'
+  use 'hrsh7th/nvim-cmp' -- Autocompletion plugin
+  use 'hrsh7th/cmp-nvim-lsp'
+  use 'saadparwaiz1/cmp_luasnip'
+  use 'L3MON4D3/LuaSnip' -- Snippets plugin
+  use 'nvim-treesitter/nvim-treesitter'
   -- Debugger --
   use 'mfussenegger/nvim-dap'
 end,

lua/treesitter.lua

@@ -0,0 +1,17 @@
+require('nvim-treesitter.configs').setup {
+  highlight = {
+    enable = true, -- false will disable the whole extension
+  },
+  incremental_selection = {
+    enable = false,
+    keymaps = {
+      init_selection = 'gnn',
+      node_incremental = 'grn',
+      scope_incremental = 'grc',
+      node_decremental = 'grm',
+    },
+  },
+  indent = {
+    enable = true,
+  }
+}