Switch from rls to rust-analyzer and from rust.vim to rust-tools.nvim

This includes some transition support for both rls and rust-analyzer
that should eventually be removed.

install-language-servers.sh

@@ -75,7 +75,7 @@ function install_language_servers() {
 
     # Rust
     if want_lang rust ;then
-        maybe_run rustup component add rls rustfmt rust-analysis rust-src clippy rustfmt
+        maybe_run rustup component add rustfmt rust-analysis rust-src clippy rust-analyzer
     fi
 
     # Go

neovim/lua/plugins.lua

@@ -269,6 +269,12 @@ use({
     requires = "neovim/nvim-lspconfig",
 })
 
+-- Rust analyzer
+use({
+    "simrat39/rust-tools.nvim",
+    disable = vim.fn.has("nvim-0.7.0") ~= 1,
+})
+
 -- Better display of lsp diagnostics
 -- TODO: Pin < 0.7 version
 use({
@@ -441,7 +447,6 @@ use({
 
 -- Filetypes
 use("ViViDboarder/vim-forcedotcom")
-use("rust-lang/rust.vim")
 use("hsanson/vim-android")
 use({
     "sheerun/vim-polyglot",

neovim/lua/plugins/lsp.lua

@@ -254,17 +254,39 @@ function M.config_lsp()
         lsp_config.bashls.setup(default_setup)
         lsp_config.gopls.setup(default_setup)
         lsp_config.pyright.setup(default_setup)
-        lsp_config.rls.setup({
+
+        -- Set up rust analyzer (preferred) or rls
+        -- TODO: Remove rls and all configuration for it when all machines are up to date
+        if vim.fn.executable("rust-analyzer") == 1 then
+            -- Prefer rust-tools, if present
+            utils.try_require("rust-tools", function(rust_tools)
+                rust_tools.setup({
+                    capabilities = capabilities,
+                    on_attach = function(client, bufnr)
+                        default_attach(client, bufnr)
+                        -- TODO: override some bindings from rust-tools
+                        -- Eg. rust_tools.hover_actions.hover_actions or rt.code_action_group.code_action_group
+                    end,
+                })
+            end, function()
+                lsp_config.rust_analyzer.setup({
                     capabilities = capabilities,
                     on_attach = default_attach,
                     settings = {
-                rust = {
-                    build_on_save = false,
-                    all_features = true,
-                    unstable_features = true,
+                        ["rust-analyzer"] = {
+                            cargo = {
+                                features = "all",
+                            },
                         },
                     },
                 })
+            end)
+        else
+            lsp_config.rls.setup({
+                capabilities = capabilities,
+                on_attach = default_attach,
+            })
+        end
 
         -- Configure neovim dev for when sumneko_lua is installed
         utils.try_require("neodev", function(neodev)