tree-sitter/grammar: make fit for public use

- Rename `source` to the more idiomatic `src`.

- Pass `version` to `mkDerivation` so that it's available in
  `drvAttrs`/`overrideAttrs`.

- Remove misleading comment about `version`.
  (nvim-treesitter sets the version to the grammar src hash.)

pkgs/applications/editors/vim/plugins/nvim-treesitter/update.py

@@ -36,7 +36,7 @@ def generate_grammar(item):
     generated = f"""  {lang} = buildGrammar {{
     language = "{lang}";
     version = "{rev[:7]}";
-    source = """
+    src = """
 
     generated += subprocess.check_output(["nurl", url, rev, "--indent=4"], text=True)
     generated += ";"

pkgs/development/tools/parsing/tree-sitter/default.nix

@@ -58,10 +58,10 @@ let
     let
       build = name: grammar:
         buildGrammar {
-          language = if grammar ? language then grammar.language else name;
+          language = grammar.language or name;
           inherit version;
-          source = if grammar ? src then grammar.src else fetchGrammar grammar;
-          location = if grammar ? location then grammar.location else null;
+          src = grammar.src or fetchGrammar grammar;
+          location = grammar.location or null;
         };
       grammars' = import ./grammars { inherit lib; } // extraGrammars;
       grammars = grammars' //

pkgs/development/tools/parsing/tree-sitter/grammar.nix

@@ -9,10 +9,8 @@
 {
   # language name
   language
-  # version of tree-sitter
 , version
-  # source for the language grammar
-, source
+, src
 , location ? null
 , generate ? false
 , ...
@@ -21,7 +19,7 @@
 stdenv.mkDerivation ({
   pname = "${language}-grammar";
 
-  src = source;
+  inherit src version;
 
   nativeBuildInputs = lib.optionals generate [ nodejs tree-sitter ];
 
@@ -60,4 +58,4 @@ stdenv.mkDerivation ({
     fi
     runHook postInstall
   '';
-} // removeAttrs args [ "language" "source" "location" "generate" ])
+} // removeAttrs args [ "language" "location" "generate" ])