From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1D6ACC5475B for ; Tue, 20 Feb 2024 15:04:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rcRfG-00034E-9C; Tue, 20 Feb 2024 10:04:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rcRfB-00033u-4b for qemu-devel@nongnu.org; Tue, 20 Feb 2024 10:04:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rcRf8-000375-FY for qemu-devel@nongnu.org; Tue, 20 Feb 2024 10:04:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708441441; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=78BikkyALO9iFBQ6S0+WLiFPvYMI43HBO7+hazm6yEc=; b=dFzUZnPbgeUhJ+UvTJ+P7IUdguMkG2j7dMh80o+f+UfNr2bQtzFv3wXqlX4/2vc2ju50bZ pJ72S0RmY+t3PL3gd9WKSJO6c6hBfCfcyg12aHHPexJRYMJ8nLlbyEKs+yd8zr64iAwSXe sI5io4sIzyJGKN/lh1s5jTaB9Fi2EaE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-343-2Gto6mXgNEKLblTmvMSzrg-1; Tue, 20 Feb 2024 10:03:57 -0500 X-MC-Unique: 2Gto6mXgNEKLblTmvMSzrg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C164E1078502; Tue, 20 Feb 2024 15:03:56 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9E997400D784; Tue, 20 Feb 2024 15:03:56 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 983E421E66D0; Tue, 20 Feb 2024 16:03:54 +0100 (CET) From: Markus Armbruster To: John Snow Cc: qemu-devel@nongnu.org, Peter Maydell , Michael Roth Subject: Re: [PATCH v3 14/20] qapi/schema: Don't initialize "members" with `None` In-Reply-To: <20240201224246.39480-15-jsnow@redhat.com> (John Snow's message of "Thu, 1 Feb 2024 17:42:40 -0500") References: <20240201224246.39480-1-jsnow@redhat.com> <20240201224246.39480-15-jsnow@redhat.com> Date: Tue, 20 Feb 2024 16:03:54 +0100 Message-ID: <87y1bf5g9x.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.05, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org John Snow writes: > Declare, but don't initialize the "members" field with type > List[QAPISchemaObjectTypeMember]. > > This simplifies the typing from what would otherwise be > Optional[List[T]] to merely List[T]. This removes the need to add > assertions to several callsites that this value is not None - which it > never will be after the delayed initialization in check() anyway. > > The type declaration without initialization trick will cause accidental > uses of this field prior to full initialization to raise an > AttributeError. > > (Note that it is valid to have an empty members list, see the internal > q_empty object as an example. For this reason, we cannot use the empty > list as a replacement test for full initialization and instead rely on > the _checked/_checking fields.) > > Signed-off-by: John Snow > --- > scripts/qapi/schema.py | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py > index a459016e148..947e7efb1a8 100644 > --- a/scripts/qapi/schema.py > +++ b/scripts/qapi/schema.py > @@ -20,7 +20,7 @@ > from collections import OrderedDict > import os > import re > -from typing import List, Optional > +from typing import List, Optional, cast > > from .common import ( > POINTER_SUFFIX, > @@ -457,7 +457,7 @@ def __init__(self, name, info, doc, ifcond, features, > self.base = None > self.local_members = local_members > self.variants = variants > - self.members = None > + self.members: List[QAPISchemaObjectTypeMember] > self._checking = False > > def check(self, schema): > @@ -474,7 +474,7 @@ def check(self, schema): > > self._checking = True > super().check(schema) > - assert self._checked and self.members is None > + assert self._checked This asserts state is "2. Being checked:. The faithful update would be assert self._checked and self._checking Or with my alternative patch assert self._checked and not self._check_complete > > seen = OrderedDict() > if self._base_name: > @@ -491,7 +491,10 @@ def check(self, schema): > for m in self.local_members: > m.check(schema) > m.check_clash(self.info, seen) > - members = seen.values() > + > + # check_clash is abstract, but local_members is asserted to be > + # List[QAPISchemaObjectTypeMember]. Cast to the narrower type. What do you mean by "check_clash is abstract"? > + members = cast(List[QAPISchemaObjectTypeMember], list(seen.values())) Do we actually need this *now*, or only later when we have more type hints? > > if self.variants: > self.variants.check(schema, seen) > @@ -524,11 +527,9 @@ def is_implicit(self): > return self.name.startswith('q_') > > def is_empty(self): > - assert self.members is not None This asserts state is "3. Checked". The faithful update would be assert self._checked and not self._checking Or with my alternative patch assert self._check_complete > return not self.members and not self.variants > > def has_conditional_members(self): > - assert self.members is not None Likewise. > return any(m.ifcond.is_present() for m in self.members) > > def c_name(self): This patch does two things: 1. Replace test of self.members (enabled by the previous patch) 2. Drop initialization of self.members and simplify the typing Observation, not demand. Wouldn't *mind* a split, though :)