compiler: Support pattern matching on record patterns

Author: tekknolagi

compiler.py

@@ -195,6 +195,15 @@ def try_match(self, env: Env, arg: str, pattern: Object, fallthrough: str) -> En
                 # Too many elements
                 self._emit(f"if (!is_empty_list({the_list})) {{ goto {fallthrough}; }}")
             return updates
+        if isinstance(pattern, Record):
+            self._emit(f"if (!is_record({arg})) {{ goto {fallthrough}; }}")
+            updates = {}
+            for key, pattern_value in pattern.data.items():
+                key_idx = self.record_key(key)
+                record_value = self._mktemp(f"record_get({arg}, {key_idx})")
+                self._emit(f"if ({record_value} == NULL) {{ goto {fallthrough}; }}")
+                updates.update(self.try_match(env, record_value, pattern_value, fallthrough))
+            return updates
         raise NotImplementedError("try_match", pattern)
 
     def compile_match_function(self, env: Env, exp: MatchFunction, name: Optional[str]) -> str:

compiler_tests.py

@@ -49,7 +49,6 @@ def test_match_int(self) -> None:
     def test_match_list(self) -> None:
         self.assertEqual(self._run("f [4, 5] . f = | [1, 2] -> 3 | [4, 5] -> 6"), "6\n")
 
-    @unittest.skip("TODO")
     def test_match_record(self) -> None:
         self.assertEqual(self._run("f {a = 4, b = 5} . f = | {a = 1, b = 2} -> 3 | {a = 4, b = 5} -> 6"), "6\n")