fixed lsp keybindings.

They now work on more than just the first buffer you open of a given
filetype.

neovim/.config/nvim/lua/cmp-lsp.lua

@@ -5,6 +5,7 @@
 local capabilities = vim.lsp.protocol.make_client_capabilities()
 capabilities = require('cmp_nvim_lsp').update_capabilities(capabilities)
 
+local luasnip = require 'luasnip'
 
 local lspconfig = require('lspconfig')
 
@@ -23,6 +24,11 @@ vim.o.completeopt = 'menuone,noselect'
 -- nvim-cmp setup
 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(),
@@ -37,6 +43,8 @@ cmp.setup {
 		['<Tab>'] = function(fallback)
 			if cmp.visible() then
 				cmp.select_next_item()
+			elseif luasnip.expand_or_jumpable() then
+				luasnip.expand_or_jump()
 			else
 				fallback()
 			end
@@ -44,6 +52,8 @@ cmp.setup {
 		['<S-Tab>'] = function(fallback)
 			if cmp.visible() then
 				cmp.select_prev_item()
+			elseif luasnip.jumpable(-1) then
+				luasnip.jump(-1)
 			else
 				fallback()
 			end
@@ -51,5 +61,7 @@ cmp.setup {
 	},
 	sources = {
 		{ name = 'nvim_lsp' },
+		{ name = 'luasnip' },
+		{ name = 'buffer' }
 	},
 }