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 D1D0AC48BC4 for ; Tue, 20 Feb 2024 10:40:12 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rcNXe-0003td-32; Tue, 20 Feb 2024 05:40:02 -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 1rcNXd-0003t0-1w for qemu-devel@nongnu.org; Tue, 20 Feb 2024 05:40:01 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rcNXb-0001ZD-N9 for qemu-devel@nongnu.org; Tue, 20 Feb 2024 05:40:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708425598; 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=7hKvs+fss1yJdd3AvC/xvyy2p8z9mPMyaHhYj3g0/YY=; b=ipOgkI/HMKBNwvjaLNZhgqmxj+EmaR2MTSdULdaKHedz9Aer5nWK8I5SrM2FMlhv0HJ0Pr BXsDvyiEi9pnr5vRoOOFfWo3qTjwYj5r2UVOmvdUT92v2AAgg+tfwCCRnK8sBAZkQ+IqWd HI/FkHQpQb7TEGzWUA5kUMOSlZqPc2o= 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-374-r-abOaYPP0yeVwxzFfF9LA-1; Tue, 20 Feb 2024 05:39:55 -0500 X-MC-Unique: r-abOaYPP0yeVwxzFfF9LA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (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 C292B86F122; Tue, 20 Feb 2024 10:39:54 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A041F492BC6; Tue, 20 Feb 2024 10:39:54 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id A2D1121E66D0; Tue, 20 Feb 2024 11:39:53 +0100 (CET) From: Markus Armbruster To: John Snow Cc: qemu-devel@nongnu.org, Peter Maydell , Michael Roth Subject: Re: [PATCH v3 08/20] qapi/schema: add type narrowing to lookup_type() In-Reply-To: <20240201224246.39480-9-jsnow@redhat.com> (John Snow's message of "Thu, 1 Feb 2024 17:42:34 -0500") References: <20240201224246.39480-1-jsnow@redhat.com> <20240201224246.39480-9-jsnow@redhat.com> Date: Tue, 20 Feb 2024 11:39:53 +0100 Message-ID: <87zfvvberq.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 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; 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=-0.072, 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: > This function is a bit hard to type as-is; mypy needs some assertions to > assist with the type narrowing. > > Signed-off-by: John Snow > --- > scripts/qapi/schema.py | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py > index 043ee7556e6..e617abb03af 100644 > --- a/scripts/qapi/schema.py > +++ b/scripts/qapi/schema.py > @@ -997,7 +997,9 @@ def lookup_entity(self, name, typ=None): def lookup_entity(self, name, typ=None): ent = self._entity_dict.get(name) if typ and not isinstance(ent, typ): return None > return ent > > def lookup_type(self, name): > - return self.lookup_entity(name, QAPISchemaType) > + typ = self.lookup_entity(name, QAPISchemaType) > + assert typ is None or isinstance(typ, QAPISchemaType) > + return typ > > def resolve_type(self, name, info, what): > typ = self.lookup_type(name) I figure the real trouble-maker is .lookup_entity(). When not passed an optional type argument, it returns QAPISchemaEntity. When passed an optional type argument, it returns that type or None. Too cute for type hints to express, I guess. What if we drop .lookup_entity()'s optional argument? There are just three callers: 1. .lookup_type(), visible above. def lookup_type(self, name): ent = self.lookup_entity(name) if isinstance(ent, QAPISchemaType): return ent return None This should permit typing it as -> Optional[QAPISchemaType] without further ado. 2. ._make_implicit_object_type() below Uses .lookup_type() to check whether the implicit object type already exists. We figure we could typ = self.lookup_entity(name) if typ: assert(isinstance(typ, QAPISchemaObjectType)) # The implicit object type has multiple users. This can 3. QAPIDocDirective.run() doesn't pass a type argument, so no change. Thoughts? If you'd prefer not to rock the boat for this series, could it still make sense as a followup?