From 62dbf84b4b1fb9568d1fe11b8566fded28226b0d Mon Sep 17 00:00:00 2001
From: John Ogle <john@ogle.fyi>
Date: Mon, 22 Sep 2025 08:26:31 -0700
Subject: [PATCH] [emacs] Prebuild tree-sitter grammars

---
 home/modules/emacs/default.nix | 77 +++++++++++++++++++++++++++++++++-
 1 file changed, 76 insertions(+), 1 deletion(-)

diff --git a/home/modules/emacs/default.nix b/home/modules/emacs/default.nix
index 4e74e75..2187c14 100644
--- a/home/modules/emacs/default.nix
+++ b/home/modules/emacs/default.nix
@@ -9,6 +9,49 @@ let
     rev = "8f55404781edacf66fa330205533b002de3fb5ee";
     sha256 = "sha256-vHwgENjip2+AFzs4oZfnKEAJKwf5Zid7fakImvxxQUw=";
   };
+
+  # Pre-built tree-sitter grammars for common languages
+  treeSitterGrammars = with pkgs.tree-sitter-grammars; [
+    # Core languages
+    tree-sitter-bash
+    tree-sitter-c
+    tree-sitter-cpp
+    tree-sitter-css
+    tree-sitter-html
+    tree-sitter-javascript
+    tree-sitter-json
+    tree-sitter-markdown
+    tree-sitter-python
+    tree-sitter-rust
+    tree-sitter-yaml
+    
+    # Configuration and markup
+    tree-sitter-dockerfile
+    tree-sitter-nix
+    tree-sitter-toml
+    
+    # Development tools and frameworks
+    tree-sitter-elisp
+    tree-sitter-typescript
+    tree-sitter-tsx
+    tree-sitter-go
+    tree-sitter-java
+    tree-sitter-lua
+    tree-sitter-make
+    tree-sitter-sql
+    
+    # Additional useful languages
+    tree-sitter-haskell
+    tree-sitter-ruby
+    tree-sitter-scala
+    tree-sitter-clojure
+    tree-sitter-scheme
+    tree-sitter-latex
+    tree-sitter-org-nvim
+    tree-sitter-vim
+    tree-sitter-regex
+    tree-sitter-comment
+  ];
 in
 {
   config = {
@@ -35,7 +78,37 @@ in
 
     fonts.fontconfig.enable = true;
 
-    home.file."${config.xdg.configHome}/emacs".source = doomEmacs;
+    # Mount emacs and tree-sitter grammars from nix store
+    home.file = {
+      "${config.xdg.configHome}/emacs".source = doomEmacs;
+    } // lib.listToAttrs (lib.flatten (map (grammar: 
+      let
+        # Extract just the language name from the package name
+        grammarName = let
+          fullName = grammar.pname or (lib.getName grammar);
+          # Remove "tree-sitter-" prefix and "-grammar" suffix
+          cleaned = lib.removePrefix "tree-sitter-" fullName;
+          final = lib.removeSuffix "-grammar" cleaned;
+        in final;
+      in [
+        # Place grammars where Emacs tree-sitter expects them
+        {
+          name = ".local/share/doom/etc/tree-sitter/libtree-sitter-${grammarName}.so";
+          value.source = "${grammar}/parser";
+        }
+        # Also place in standard tree-sitter location as backup
+        {
+          name = ".local/share/tree-sitter/bin/libtree-sitter-${grammarName}.so";
+          value.source = "${grammar}/parser";
+        }
+      ] ++ lib.optionals (builtins.pathExists "${grammar}/queries") [
+        {
+          name = ".local/share/tree-sitter/queries/${grammarName}";
+          value.source = "${grammar}/queries";
+        }
+      ]
+    ) treeSitterGrammars));
+
     home.sessionPath = [
       "${config.xdg.configHome}/emacs/bin"
     ];
@@ -43,6 +116,8 @@ in
     home.sessionVariables = {
       DOOMDIR = "${config.xdg.configHome}/doom";
       DOOMLOCALDIR = "${config.xdg.dataHome}/doom";
+      # Set tree-sitter grammar directory to use pre-built grammars
+      TREE_SITTER_DIR = "${config.xdg.dataHome}/tree-sitter";
     };
 
     home.activation.doomConfig = lib.hm.dag.entryAfter ["writeBoundary"] ''