val:ty

aggen.py

@@ -155,9 +155,16 @@ def gen(program: List[Decl]) -> GenResult:
         assert isinstance(node_desc, NodeDesc)
         res.starts.add(node_desc.nonterminal)
 
+        class_fields = []
+        for field_name, field_ty in what_fields[node_desc.name].items():
+            class_fields.append(f"{field_name}: Thunk[{field_ty}]")
+        g = textwrap.indent("\n".join(class_fields), "    ")
+
         class_decl = textwrap.dedent(
             f"""
-            class {node_desc.nonterminal}: pass
+            class {node_desc.nonterminal}:
+            {g}
+                pass
             """
         )
         res.extra += class_decl
@@ -168,9 +175,7 @@ def gen(program: List[Decl]) -> GenResult:
             v_class_name = gensym(f"{node_desc.nonterminal}_var")
             class_decl = textwrap.dedent(
                 f"""
-                class {v_class_name}({node_desc.nonterminal}):
-                    ''' '''
-                    pass
+                class {v_class_name}({node_desc.nonterminal}): pass
                 """
             )
             res.extra += class_decl

agmain.py

@@ -24,8 +24,11 @@ if __name__ == "__main__":
 
     if not os.path.exists("gen"):
         os.makedirs("gen")
+
+    with open("agruntime.tmpl.py", "r") as f:
+        fmt_str = f.read()
+
     with open("gen/arith.py", "w") as f:
-        fmt_str = open("agruntime.tmpl.py", "r").read()
         f.write(
             fmt_str.format(
                 pd=res.parser_data,