Working simple tree-sitter grammar

doesn't work yet

experiments/tree-sitter-test/grammar.js

@@ -9,17 +9,20 @@ module.exports = grammar({
         ),
 
         function_definition: $ => seq(
-            "fn",
+            'fn',
             $.identifier,
             $.parameter_list,
-            $._type,
+            field("return_type", optional($._type)),
             $.block,
         ),
         parameter_list: $ => seq("(", /* TODO */ ")"),
 
         block: $ => seq(
             "{",
-            repeat($._statement),
+            choice(
+                repeat($._statement),
+                "",
+            ),
             "}"
         ),
 
@@ -29,9 +32,16 @@ module.exports = grammar({
 
         _return_statement: $ => seq("return", $._expression, ";"),
 
-        _expression: $ => choice($.identifier),
+        _expression: $ => choice($.identifier, $.unary, $.binary),
+
+        unary: $ => prec(4, choice(seq("-", $._expression), seq("!", $._expression))),
+        binary: $ => choice(prec.left(2, seq($._expression, "*", $._expression)), prec.left(1, seq($._expression, "+", $._expression))),
 
         _type: $ => "bool",
+        _type: $ => choice(
+            $.primitive_type,
+        ),
+        primitive_type: $ => choice("bool", "int"),
 
         identifier: $ => /[a-z]+/,
     }

experiments/tree-sitter-test/justfile

@@ -0,0 +1,8 @@
+_default:
+    just --list
+
+# Test out the grammar
+test-grammar:
+    #!/usr/bin/env bash
+    tree-sitter generate
+    tree-sitter test

experiments/tree-sitter-test/test/corpus/test.txt

@@ -1,19 +1,26 @@
 =============
 Initial test
 =============
+fn main() {
 
-hello
+}
+----
+(source_file
+    (function_definition
+        (identifier)
+        (parameter_list)
+        (block)
+    )
+)
+
+====
+Another test
+====
+
+fn yolo() bool { }
 
 ----
 
-(source_file)
+(source_file
-
+    (function_definition
-
+    (identifier) (parameter_list) (primitive_type) (block)))
-=====
-Another
-====
-
-fn main() { }
-
-------
-()