scala

shared/home/default.nix

@@ -21,6 +21,7 @@
         zigpkgs."0.11.0"
 
         scala_2_12
+        metals
         coursier
       ])
     else [];
@@ -43,12 +44,20 @@
 
           zig-vim
 
+          cmp-nvim-lsp
+          nvim-cmp
           nvim-metals
           plenary-nvim
         ]
         else []
       );
-    extraLuaConfig = builtins.readFile ./init.lua;
+    extraLuaConfig =
+      builtins.readFile
+      (pkgs.substituteAll {
+        src = ./init.lua;
+        inherit (pkgs) metals;
+      })
+      .outPath;
   };
 
   programs.git = {

shared/home/init.lua

@@ -74,3 +74,131 @@ vim.api.nvim_exec([[
     " TeX
     au FileType tex setlocal spell spelllang=en_us ts=2 sw=2 sts=2
 ]], false)
+
+local api = vim.api
+local cmd = vim.cmd
+local map = vim.keymap.set
+
+----------------------------------
+-- OPTIONS -----------------------
+----------------------------------
+-- global
+vim.opt_global.completeopt = { "menuone", "noinsert", "noselect" }
+vim.opt_global.shortmess:remove("F")
+
+-- LSP mappings
+map("n", "gD",  vim.lsp.buf.definition)
+map("n", "K",  vim.lsp.buf.hover)
+map("n", "gi", vim.lsp.buf.implementation)
+map("n", "gr", vim.lsp.buf.references)
+map("n", "gds", vim.lsp.buf.document_symbol)
+map("n", "gws", vim.lsp.buf.workspace_symbol)
+map("n", "<leader>cl", vim.lsp.codelens.run)
+map("n", "<leader>sh", vim.lsp.buf.signature_help)
+map("n", "<leader>rn", vim.lsp.buf.rename)
+map("n", "<leader>f", vim.lsp.buf.format)
+map("n", "<leader>ca", vim.lsp.buf.code_action)
+
+map("n", "<leader>ws", function()
+  require("metals").hover_worksheet()
+end)
+
+-- all workspace diagnostics
+map("n", "<leader>aa", vim.diagnostic.setqflist)
+
+-- all workspace errors
+map("n", "<leader>ae", function()
+  vim.diagnostic.setqflist({ severity = "E" })
+end)
+
+-- all workspace warnings
+map("n", "<leader>aw", function()
+  vim.diagnostic.setqflist({ severity = "W" })
+end)
+
+-- buffer diagnostics only
+map("n", "<leader>d", vim.diagnostic.setloclist)
+
+map("n", "[c", function()
+  vim.diagnostic.goto_prev({ wrap = false })
+end)
+
+map("n", "]c", function()
+  vim.diagnostic.goto_next({ wrap = false })
+end)
+
+-- completion related settings
+-- This is similiar to what I use
+local cmp = require("cmp")
+cmp.setup({
+  sources = {
+    { name = "nvim_lsp" },
+    { name = "vsnip" },
+  },
+  snippet = {
+    expand = function(args)
+      -- Comes from vsnip
+      vim.fn["vsnip#anonymous"](args.body)
+    end,
+  },
+  mapping = cmp.mapping.preset.insert({
+    -- None of this made sense to me when first looking into this since there
+    -- is no vim docs, but you can't have select = true here _unless_ you are
+    -- also using the snippet stuff. So keep in mind that if you remove
+    -- snippets you need to remove this select
+    ["<CR>"] = cmp.mapping.confirm({ select = true }),
+    -- I use tabs... some say you should stick to ins-completion but this is just here as an example
+    ["<Tab>"] = function(fallback)
+      if cmp.visible() then
+        cmp.select_next_item()
+      else
+        fallback()
+      end
+    end,
+    ["<S-Tab>"] = function(fallback)
+      if cmp.visible() then
+        cmp.select_prev_item()
+      else
+        fallback()
+      end
+    end,
+  }),
+})
+
+
+
+----------------------------------
+-- LSP Setup ---------------------
+----------------------------------
+local metals_config = require("metals").bare_config()
+
+-- Example of settings
+metals_config.settings = {
+  showImplicitArguments = true,
+  excludedPackages = { "akka.actor.typed.javadsl", "com.github.swagger.akka.javadsl" },
+  --useGlobalExecutable = true, -- nix addition
+  metalsBinaryPath = "@metals@/bin/metals",
+}
+
+-- *READ THIS*
+-- I *highly* recommend setting statusBarProvider to true, however if you do,
+-- you *have* to have a setting to display this in your statusline or else
+-- you'll not see any messages from metals. There is more info in the help
+-- docs about this
+ metals_config.init_options.statusBarProvider = "on"
+
+-- Example if you are using cmp how to make sure the correct capabilities for snippets are set
+metals_config.capabilities = require("cmp_nvim_lsp").default_capabilities()
+
+-- Autocmd that will actually be in charging of starting the whole thing
+local nvim_metals_group = api.nvim_create_augroup("nvim-metals", { clear = true })
+api.nvim_create_autocmd("FileType", {
+  -- NOTE: You may or may not want java included here. You will need it if you
+  -- want basic Java support but it may also conflict if you are using
+  -- something like nvim-jdtls which also works on a java filetype autocmd.
+  pattern = { "scala", "sbt", "java" },
+  callback = function()
+    require("metals").initialize_or_attach(metals_config)
+  end,
+  group = nvim_metals_group,
+})