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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]:36772 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kQDsp-0002ct-Bf for qemu-devel@archiver.kernel.org; Wed, 07 Oct 2020 14:09:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38622) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kQDrl-0002AH-PY for qemu-devel@nongnu.org; Wed, 07 Oct 2020 14:08:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:59249) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kQDrj-0005Rs-Fl for qemu-devel@nongnu.org; Wed, 07 Oct 2020 14:08:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602094118; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YcJfQ/HnFLSPuGUUaCy3jliGWVn5YAGiy5gfRONdT6c=; b=EuKUl7KMYHzdITjfHq6+wDgYSRtI430/L/v+SXuDa9g0S52N7qSmYzMLW8V+Q4CPx8VSKQ CHAAbAC9wRipskDm9Ms8wCYl3fg693PHrqJFSIRkv6CuyJorvBloCz79qaryiouHID7l/9 CT6nHS7oKHE69Cz06fhKAMRWbuCCDr8= 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-176-tQf6zMhXMhOHk89UtSr4ow-1; Wed, 07 Oct 2020 14:08:35 -0400 X-MC-Unique: tQf6zMhXMhOHk89UtSr4ow-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B968D420EA for ; Wed, 7 Oct 2020 18:08:34 +0000 (UTC) Received: from [10.10.120.38] (ovpn-120-38.rdu2.redhat.com [10.10.120.38]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC9A276642; Wed, 7 Oct 2020 18:08:33 +0000 (UTC) Subject: Re: [PATCH v5 11/36] qapi/common.py: Add indent manager To: Markus Armbruster References: <20201005195158.2348217-1-jsnow@redhat.com> <20201005195158.2348217-12-jsnow@redhat.com> <87d01uifmn.fsf@dusky.pond.sub.org> From: John Snow Message-ID: <0a507019-1e59-2967-9c7a-fa3712a74ae0@redhat.com> Date: Wed, 7 Oct 2020 14:08:33 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <87d01uifmn.fsf@dusky.pond.sub.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/07 00:44:56 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.742, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=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: qemu-devel@nongnu.org, Eduardo Habkost , Cleber Rosa Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 10/7/20 4:50 AM, Markus Armbruster wrote: > John Snow writes: > >> Code style tools really dislike the use of global keywords, because it >> generally involves re-binding the name at runtime which can have strange >> effects depending on when and how that global name is referenced in >> other modules. >> >> Make a little indent level manager instead. >> >> Signed-off-by: John Snow >> Reviewed-by: Eduardo Habkost >> Reviewed-by: Cleber Rosa > > Intentation is a job for QAPIGen (and its subtypes). But if this patch > is easier to achieve this series' goal, I don't mind. > I agree, but refactoring it properly is beyond my capacity right now. This was the dumbest thing I could do to get pylint/mypy passing, which required the elimination (or suppression) of the global keyword. Creating a stateful object was the fastest way from A to B. >> --- >> scripts/qapi/common.py | 49 ++++++++++++++++++++++++++++-------------- >> scripts/qapi/visit.py | 7 +++--- >> 2 files changed, 36 insertions(+), 20 deletions(-) >> >> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py >> index cee63eb95c7..b35318b72cf 100644 >> --- a/scripts/qapi/common.py >> +++ b/scripts/qapi/common.py >> @@ -93,33 +93,50 @@ def c_name(name, protect=True): >> pointer_suffix = ' *' + eatspace >> >> >> -def genindent(count): >> - ret = '' >> - for _ in range(count): >> - ret += ' ' >> - return ret >> +class Indentation: >> + """ >> + Indentation level management. >> >> + :param initial: Initial number of spaces, default 0. >> + """ >> + def __init__(self, initial: int = 0) -> None: >> + self._level = initial >> >> -indent_level = 0 >> + def __int__(self) -> int: >> + return self._level >> >> + def __repr__(self) -> str: >> + return "{}({:d})".format(type(self).__name__, self._level) >> >> -def push_indent(indent_amount=4): >> - global indent_level >> - indent_level += indent_amount >> + def __str__(self) -> str: >> + """Return the current indentation as a string of spaces.""" >> + return ' ' * self._level >> >> + def __bool__(self) -> bool: >> + """True when there is a non-zero indentation.""" >> + return bool(self._level) >> >> -def pop_indent(indent_amount=4): >> - global indent_level >> - indent_level -= indent_amount >> + def increase(self, amount: int = 4) -> None: >> + """Increase the indentation level by ``amount``, default 4.""" >> + self._level += amount >> + >> + def decrease(self, amount: int = 4) -> None: >> + """Decrease the indentation level by ``amount``, default 4.""" >> + if self._level < amount: >> + raise ArithmeticError( >> + f"Can't remove {amount:d} spaces from {self!r}") > > Raise a fancy error when there's an actual need for it. You're not > coding a framework thousands of people you never heard of will put to > uses you cannot imagine. > It's not fancy, it's just a normal built-in exception, like AssertionError or any other: Traceback (most recent call last): File "", line 1, in ArithmeticError: Can't remove 4 spaces from Indent(0) vs Traceback (most recent call last): File "", line 1, in AssertionError: Can't remove 4 spaces from Indent(0) I feel like it's kind of a lateral move? I realize you feel this is an overfancy class doing what we hope is a temporary job, and that I have overengineered the hell out of a tiny do-nothing class... but I suppose that's also why I feel weird changing it around so much to accomplish so little. Differences in style, I suppose. Feel free to change it around to suit your tastes, I don't think it's worth spending a lot of ping-pong time on this paintsink in particular. --js >> + self._level -= amount >> + >> + >> +indent = Indentation() >> >> >> # Generate @code with @kwds interpolated. >> -# Obey indent_level, and strip eatspace. >> +# Obey indent, and strip eatspace. >> def cgen(code, **kwds): >> raw = code % kwds >> - if indent_level: >> - indent = genindent(indent_level) >> - raw = re.sub(r'^(?!(#|$))', indent, raw, flags=re.MULTILINE) >> + if indent: >> + raw = re.sub(r'^(?!(#|$))', str(indent), raw, flags=re.MULTILINE) >> return re.sub(re.escape(eatspace) + r' *', '', raw) >> >> >> diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py >> index 808410d6f1b..14f30c228b7 100644 >> --- a/scripts/qapi/visit.py >> +++ b/scripts/qapi/visit.py >> @@ -18,9 +18,8 @@ >> c_name, >> gen_endif, >> gen_if, >> + indent, >> mcgen, >> - pop_indent, >> - push_indent, >> ) >> from .gen import QAPISchemaModularCVisitor, ifcontext >> from .schema import QAPISchemaObjectType >> @@ -69,7 +68,7 @@ def gen_visit_object_members(name, base, members, variants): >> if (visit_optional(v, "%(name)s", &obj->has_%(c_name)s)) { >> ''', >> name=memb.name, c_name=c_name(memb.name)) >> - push_indent() >> + indent.increase() >> ret += mcgen(''' >> if (!visit_type_%(c_type)s(v, "%(name)s", &obj->%(c_name)s, errp)) { >> return false; >> @@ -78,7 +77,7 @@ def gen_visit_object_members(name, base, members, variants): >> c_type=memb.type.c_name(), name=memb.name, >> c_name=c_name(memb.name)) >> if memb.optional: >> - pop_indent() >> + indent.decrease() >> ret += mcgen(''' >> } >> ''')