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 X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16081C433E6 for ; Mon, 8 Feb 2021 20:57:19 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 59D2764E05 for ; Mon, 8 Feb 2021 20:57:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59D2764E05 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54916 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l9Dav-0007eN-4U for qemu-devel@archiver.kernel.org; Mon, 08 Feb 2021 15:57:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59328) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l97f0-00040R-7x for qemu-devel@nongnu.org; Mon, 08 Feb 2021 09:37:07 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48946) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l97ep-0003FO-8b for qemu-devel@nongnu.org; Mon, 08 Feb 2021 09:37:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612795013; 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=Og0bf40V5z/6NwlcZDfD5vqAhvqwOQd2e9DyW4eX2Ww=; b=MWw435jPtb8lGTXKJEvHnTz7xhtGwMopC4XyN7ZAEyVocieRua7SWX2wnxZOicjfqNjNIk KE0wg430ApHwtiTePvDuUdH/IdcXubKoLoT0K80b9Y1S//nopPDlijmVsQrpxo3Fq/RGUs J7SO60U+ZcU7glWHMfLIe9qQQd/b7DQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-301-maIdpotxOGqkMxe04Ual3A-1; Mon, 08 Feb 2021 09:36:50 -0500 X-MC-Unique: maIdpotxOGqkMxe04Ual3A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2637619357A7 for ; Mon, 8 Feb 2021 14:36:49 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-115-51.ams2.redhat.com [10.36.115.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C57995D9DE; Mon, 8 Feb 2021 14:36:48 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 52C28113865F; Mon, 8 Feb 2021 15:36:47 +0100 (CET) From: Markus Armbruster To: John Snow Subject: Re: [PATCH v5 09/15] qapi/introspect.py: create a typed 'Annotated' data strutcure References: <20210204003207.2856909-1-jsnow@redhat.com> <20210204003207.2856909-10-jsnow@redhat.com> Date: Mon, 08 Feb 2021 15:36:47 +0100 In-Reply-To: <20210204003207.2856909-10-jsnow@redhat.com> (John Snow's message of "Wed, 3 Feb 2021 19:32:01 -0500") Message-ID: <87blcu4oe8.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.57, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cleber Rosa , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" John Snow writes: > Presently, we use a tuple to attach a dict containing annotations > (comments and compile-time conditionals) to a tree node. This is > undesirable because dicts are difficult to strongly type; promoting it > to a real class allows us to name the values and types of the > annotations we are expecting. > > In terms of typing, the Annotated type serves as a generic container > where the annotated node's type is preserved, allowing for greater > specificity than we'd be able to provide without a generic. > > Signed-off-by: John Snow > --- > scripts/qapi/introspect.py | 77 ++++++++++++++++++++++---------------- > 1 file changed, 44 insertions(+), 33 deletions(-) > > diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py > index 8e019b4a26a..b9427aba449 100644 > --- a/scripts/qapi/introspect.py > +++ b/scripts/qapi/introspect.py > @@ -13,8 +13,12 @@ > from typing import ( > Any, > Dict, > + Generic, > + Iterable, > List, > Optional, > + Tuple, > + TypeVar, > Union, > ) > > @@ -51,15 +55,25 @@ > _scalar = Union[str, bool, None] > _nonscalar = Union[Dict[str, _stub], List[_stub]] > _value = Union[_scalar, _nonscalar] > -# TreeValue = TODO, in a forthcoming commit. > +TreeValue = Union[_value, 'Annotated[_value]'] > > > -def _make_tree(obj, ifcond, comment=None): > - extra = { > - 'if': ifcond, > - 'comment': comment > - } > - return (obj, extra) > +_NodeT = TypeVar('_NodeT', bound=_value) > + > + > +class Annotated(Generic[_NodeT]): My gut feeling is "generic type is overkill for this purpose". Let's go with it anyway, because 1. It's not wrong. 2. I don't have enough experience with Python type hints for reliable gut feelings. 3. I plan to overhaul the C generation part relatively soon (after your work has landed, don't worry), and I can try to make it simpler then. > + """ > + Annotated generally contains a SchemaInfo-like type (as a dict), > + But it also used to wrap comments/ifconds around scalar leaf values, > + for the benefit of features and enums. > + """ > + # TODO: Remove after Python 3.7 adds @dataclass: > + # pylint: disable=too-few-public-methods > + def __init__(self, value: _NodeT, ifcond: Iterable[str], > + comment: Optional[str] = None): > + self.value = value > + self.comment: Optional[str] = comment > + self.ifcond: Tuple[str, ...] = tuple(ifcond) > > > def _tree_to_qlit(obj, level=0, dict_value=False): > @@ -67,24 +81,20 @@ def _tree_to_qlit(obj, level=0, dict_value=False): > def indent(level): > return level * 4 * ' ' > > - if isinstance(obj, tuple): > - ifobj, extra = obj > - ifcond = extra.get('if') > - comment = extra.get('comment') > - > + if isinstance(obj, Annotated): > # NB: _tree_to_qlit is called recursively on the values of a key:value > # pair; those values can't be decorated with comments or conditionals. > msg = "dict values cannot have attached comments or if-conditionals." > assert not dict_value, msg > > ret = '' > - if comment: > - ret += indent(level) + '/* %s */\n' % comment > - if ifcond: > - ret += gen_if(ifcond) > - ret += _tree_to_qlit(ifobj, level) > - if ifcond: > - ret += '\n' + gen_endif(ifcond) > + if obj.comment: > + ret += indent(level) + '/* %s */\n' % obj.comment > + if obj.ifcond: > + ret += gen_if(obj.ifcond) > + ret += _tree_to_qlit(obj.value, level) > + if obj.ifcond: > + ret += '\n' + gen_endif(obj.ifcond) > return ret > > ret = '' > @@ -201,7 +211,7 @@ def _use_type(self, typ): > > @staticmethod > def _gen_features(features): > - return [_make_tree(f.name, f.ifcond) for f in features] > + return [Annotated(f.name, f.ifcond) for f in features] > > def _gen_tree(self, name, mtype, obj, ifcond, features): > comment: Optional[str] = None > @@ -215,7 +225,7 @@ def _gen_tree(self, name, mtype, obj, ifcond, features): > obj['meta-type'] = mtype > if features: > obj['features'] = self._gen_features(features) > - self._trees.append(_make_tree(obj, ifcond, comment)) > + self._trees.append(Annotated(obj, ifcond, comment)) > > def _gen_member(self, member): > obj = {'name': member.name, 'type': self._use_type(member.type)} > @@ -223,7 +233,7 @@ def _gen_member(self, member): > obj['default'] = None > if member.features: > obj['features'] = self._gen_features(member.features) > - return _make_tree(obj, member.ifcond) > + return Annotated(obj, member.ifcond) > > def _gen_variants(self, tag_name, variants): > return {'tag': tag_name, > @@ -231,16 +241,17 @@ def _gen_variants(self, tag_name, variants): > > def _gen_variant(self, variant): > obj = {'case': variant.name, 'type': self._use_type(variant.type)} > - return _make_tree(obj, variant.ifcond) > + return Annotated(obj, variant.ifcond) > > def visit_builtin_type(self, name, info, json_type): > self._gen_tree(name, 'builtin', {'json-type': json_type}, [], None) > > def visit_enum_type(self, name, info, ifcond, features, members, prefix): > - self._gen_tree(name, 'enum', > - {'values': [_make_tree(m.name, m.ifcond, None) > - for m in members]}, > - ifcond, features) > + self._gen_tree( > + name, 'enum', > + {'values': [Annotated(m.name, m.ifcond) for m in members]}, > + ifcond, features > + ) > > def visit_array_type(self, name, info, ifcond, element_type): > element = self._use_type(element_type) > @@ -257,12 +268,12 @@ def visit_object_type_flat(self, name, info, ifcond, features, > self._gen_tree(name, 'object', obj, ifcond, features) > > def visit_alternate_type(self, name, info, ifcond, features, variants): > - self._gen_tree(name, 'alternate', > - {'members': [ > - _make_tree({'type': self._use_type(m.type)}, > - m.ifcond, None) > - for m in variants.variants]}, > - ifcond, features) > + self._gen_tree( > + name, 'alternate', > + {'members': [Annotated({'type': self._use_type(m.type)}, m.ifcond) > + for m in variants.variants]}, Slightly more readable, I think: {'members': [Annotated({'type': self._use_type(m.type)}, m.ifcond) for m in variants.variants]}, > + ifcond, features > + ) > > def visit_command(self, name, info, ifcond, features, > arg_type, ret_type, gen, success_response, boxed,