ASDL

-- ASDL's 4 built-in types are:
-- identifier, int, string, constant

module Python
{
    mod = Module(stmt* body, type_ignore* type_ignores)
        | Interactive(stmt* body)
        | Expression(expr body)
        | FunctionType(expr* argtypes, expr returns)

    stmt = FunctionDef(identifier name, arguments args,
                        stmt* body, expr* decorator_list, expr? returns,
                        string? type_comment)
         | AsyncFunctionDef(identifier name, arguments args,
                              stmt* body, expr* decorator_list, expr? returns,
                              string? type_comment)
         | ClassDef(identifier name,
                     expr* bases,
                     keyword* keywords,
                     stmt* body,
                     expr* decorator_list)
         | Return(expr? value)
         | Delete(expr* targets)
         | Assign(expr* targets, expr value, string? type_comment)
         | AugAssign(expr target, operator op, expr value)
         | AnnAssign(expr target, expr annotation, expr? value, int simple)

    expr = BoolOp(boolop op, expr* values)
         | NamedExpr(expr target, expr value)
         | BinOp(expr left, operator op, expr right)
         | UnaryOp(unaryop op, expr operand)
         | Lambda(arguments args, expr body)
         | IfExp(expr test, expr body, expr orelse)
         | Dict(expr* keys, expr* values)
         | Set(expr* elts)
         | ListComp(expr elt, comprehension* generators)
         | Constant(constant value, string? kind)
         | Name(identifier id, expr_context ctx)
         | List(expr* elts, expr_context ctx)
         | Tuple(expr* elts, expr_context ctx)

    boolop = And | Or

    operator = Add | Sub | Mult | MatMult | Div | Mod | Pow | LShift
             | RShift | BitOr | BitXor | BitAnd | FloorDiv

    unaryop = Invert | Not | UAdd | USub

    cmpop = Eq | NotEq | Lt | LtE | Gt | GtE | Is | IsNot | In | NotIn

    expr_context = Load | Store | Del

    comprehension = (expr target, expr iter, expr* ifs, int is_async)

    arguments = (arg* posonlyargs, arg* args, arg? vararg, arg* kwonlyargs,
                 expr* kw_defaults, arg? kwarg, expr* defaults)

    arg = (identifier arg, expr? annotation, string? type_comment)
          attributes (int lineno, int col_offset, int? end_lineno,
                      int? end_col_offset)

    type_ignore = TypeIgnore(int lineno, string tag)
}