Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:63731 Return-Path: Mailing-List: contact internals-help@lists.php.net; run by ezmlm Delivered-To: mailing list internals@lists.php.net Received: (qmail 69950 invoked from network); 31 Oct 2012 19:46:36 -0000 Received: from unknown (HELO lists.php.net) (127.0.0.1) by localhost with SMTP; 31 Oct 2012 19:46:36 -0000 Authentication-Results: pb1.pair.com smtp.mail=smalyshev@sugarcrm.com; spf=pass; sender-id=pass Authentication-Results: pb1.pair.com header.from=smalyshev@sugarcrm.com; sender-id=pass Received-SPF: pass (pb1.pair.com: domain sugarcrm.com designates 67.192.241.143 as permitted sender) X-PHP-List-Original-Sender: smalyshev@sugarcrm.com X-Host-Fingerprint: 67.192.241.143 smtp143.dfw.emailsrvr.com Linux 2.6 Received: from [67.192.241.143] ([67.192.241.143:45467] helo=smtp143.dfw.emailsrvr.com) by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP id 74/B7-24645-A1081905 for ; Wed, 31 Oct 2012 14:46:35 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp24.relay.dfw1a.emailsrvr.com (SMTP Server) with ESMTP id 35A791800D4; Wed, 31 Oct 2012 15:46:32 -0400 (EDT) X-Virus-Scanned: OK Received: by smtp24.relay.dfw1a.emailsrvr.com (Authenticated sender: smalyshev-AT-sugarcrm.com) with ESMTPSA id C39E8180321; Wed, 31 Oct 2012 15:46:31 -0400 (EDT) Message-ID: <50918018.4010501@sugarcrm.com> Date: Wed, 31 Oct 2012 12:46:32 -0700 Organization: SugarCRM User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 MIME-Version: 1.0 To: Etienne Kneuss CC: Nikita Popov , Clint Priest , PHP Developers Mailing List References: <508A67E6.2000405@zerocue.com> <508A9AC9.50200@sugarcrm.com> <508AF3E7.7020004@sugarcrm.com> <508B1EA2.8060203@sugarcrm.com> <508C249D.1000309@zerocue.com> <508C43ED.9000209@sugarcrm.com> <508C80C6.9000008@zerocue.com> <508CD916.1070509@sugarcrm.com> <508D5462.4070503@zerocue.com> <508EFB76.4080604@sugarcrm.com> <50904C0C.8030207@sugarcrm.com> <50905FBD.1080208@sugarcrm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [PHP-DEV] [RFC] Property Accessors v1.2 : Internal Accessor Method Visibility / Callability From: smalyshev@sugarcrm.com (Stas Malyshev) Hi! > Well, LSP is typically not applied to program semantics, since this is > not a generally decidable problem. The only post-conditions that LSP > normally enforces is type based, i.e. the covariance of the return > type. Err, I'm not sure where you are taking this from, but LSP is certainly not limited to return types. See: https://en.wikipedia.org/wiki/Liskov_substitution_principle If you look at classic Square/Rectangle example, it's all about semantics and has nothing to do with types. > Instead, LSP simply states that, given B <: A, all objects of A can be > substituted by objects of B while preserving the validity of the > method calls on these objects, and the validity of their return > values. This is guaranteed here: I would suggest at that point reading actual description of the LSP. You rendition of it is wrong. -- Stanislav Malyshev, Software Architect SugarCRM: http://www.sugarcrm.com/ (408)454-6900 ext. 227