Add LSP basics (PHP)

Add for PHP via existing phpactor as server.
Use new signature plugin for proper none irritating inline help during
function calls.

TODO: Get rid of preview window showing up …

home/programs/neovim.nix

@@ -314,6 +314,27 @@ in {
       '';
     }
 
+    # LSP (=Language Server Protocol)
+
+    {
+      plugin = nvim-lspconfig;
+      type = "lua";
+      config = ''
+        require'lspconfig'.phpactor.setup({
+          cmd = {
+            '${phpactor}/bin/phpactor',
+            'language-server',
+          },
+        })
+      '';
+    }
+
+    {
+      plugin = lsp_signature-nvim;
+      type = "lua";
+      config = pkgs.lib.fileContents ./neovim/plugins/lsp-signature.lua;
+    }
+
     # More related to testing, linting, …
 
     {

home/programs/neovim/configuration/after/ftplugin/php.vim

@@ -7,8 +7,6 @@ syn spell toplevel
 set nospell
 
 if exists('&omnifunc') && exists('g:loaded_phpactor')
-    setlocal omnifunc=phpactor#Complete
-    " Would enable autocompletion via lsp
-    " setlocal omnifunc=v:lua.vim.lsp.omnifunc
+    setlocal omnifunc=v:lua.vim.lsp.omnifunc
 endif
 

home/programs/neovim/plugins/lsp-signature.lua

@@ -0,0 +1,4 @@
+require "lsp_signature".setup({
+    -- For now, as this would hide parts of autocomplete
+    floating_window = false,
+})