neovim: Add LanguageTool language server

users/simon/modules/git.nix

@@ -11,6 +11,11 @@
     };
 
     extraConfig = {
+      # Make LTeX not check anything below this.
+      # I often use git commit -v, which adds a full diff that should not be checked.
+      commit.template = toString (pkgs.writeText "git-commit-template" ''
+
+        # LTeX: enabled=false'');
       core.quotepath = "off";
       pull.ff = "only";
       diff = {

users/simon/modules/neovim/default.nix

@@ -48,6 +48,7 @@ in
       gopls
       haskell-language-server
       jdt-language-server
+      unstable.ltex-ls
       rnix-lsp
       rust-analyzer
       (python3.withPackages (ps: with ps; [

users/simon/modules/neovim/init.lua

@@ -290,6 +290,47 @@ lsp.jdtls.setup {
     on_attach = on_attach,
     cmd = {'jdt-language-server', '-configuration', '/home/simon/.cache/jdtls/config', '-data', '/home/simon/.cache/jdtls/workspace'}, -- copied from upstream, but changed executable name
 }
+lsp.ltex.setup {
+    on_attach = on_attach,
+    settings = {
+        ltex = {
+            language = 'en-GB',
+            languageToolHttpServerUri = 'https://languagetool.sbruder.de/',
+        },
+    },
+    -- both taken from upstream, extended
+    filetypes = {
+        'bib',
+        'gitcommit',
+        'mail',
+        'markdown',
+        'org',
+        'plaintex',
+        'rst',
+        'rnoweb',
+        'tex',
+        'pandoc'
+    },
+    get_language_id = function(_, filetype)
+        local language_id_mapping = {
+            bib = 'bibtex',
+            gitcommit = 'git-commit',
+            mail = 'markdown', -- quite wrong, but allows magic commands
+            pandoc = 'markdown',
+            plaintex = 'tex',
+            rnoweb = 'sweave',
+            rst = 'restructuredtext',
+            tex = 'latex',
+            xhtml = 'xhtml',
+        }
+        local language_id = language_id_mapping[filetype]
+        if language_id then
+            return language_id
+        else
+            return filetype
+        end
+    end,
+}
 lsp.pylsp.setup {
     on_attach = on_attach,
 }