From 02f89ac524cef1c982b4292daed07c2af41931a5 Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Fri, 3 Jun 2022 14:48:15 +0200
Subject: [PATCH] Refactor nix package

Introduce an overlay, and use the existing 'tree-sitter' package
machinery to extend it with this grammar.

Expose the extended 'tree-sitter' as part of the flake packages.
---
 flake.nix | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/flake.nix b/flake.nix
index 31ecee0..9d3cfdd 100644
--- a/flake.nix
+++ b/flake.nix
@@ -51,9 +51,8 @@
       let
         pkgs = import nixpkgs {
           inherit system;
+          overlays = [ self.overlays.default ];
         };
-
-        version = (builtins.fromJSON (builtins.readFile ./package.json)).version;
       in
       rec {
         checks = {
@@ -104,14 +103,23 @@
         };
 
         packages = {
-          default =
-            let mkGrammar = pkgs.callPackage "${nixpkgs}/pkgs/development/tools/parsing/tree-sitter/grammar.nix" { };
-            in
-            mkGrammar {
-              language = "tiger";
-              inherit version;
-              source = ./.;
-            };
+          default = packages.tree-sitter-tiger;
+
+          inherit (pkgs.tree-sitter.passthru.builtGrammars) tree-sitter-tiger;
+
+          inherit (pkgs) tree-sitter;
         };
-      });
+      }) // {
+      overlays = {
+        default = final: prev: {
+          tree-sitter = prev.tree-sitter.override {
+            extraGrammars = {
+              tree-sitter-tiger = {
+                src = ./.;
+              };
+            };
+          };
+        };
+      };
+    };
 }