Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:85200 Return-Path: Mailing-List: contact internals-help@lists.php.net; run by ezmlm Delivered-To: mailing list internals@lists.php.net Received: (qmail 61409 invoked from network); 18 Mar 2015 17:30:37 -0000 Received: from unknown (HELO lists.php.net) (127.0.0.1) by localhost with SMTP; 18 Mar 2015 17:30:37 -0000 Authentication-Results: pb1.pair.com header.from=are.you.winning@gmail.com; sender-id=pass Authentication-Results: pb1.pair.com smtp.mail=are.you.winning@gmail.com; spf=pass; sender-id=pass Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.212.169 as permitted sender) X-PHP-List-Original-Sender: are.you.winning@gmail.com X-Host-Fingerprint: 209.85.212.169 mail-wi0-f169.google.com Received: from [209.85.212.169] ([209.85.212.169:37838] helo=mail-wi0-f169.google.com) by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP id FC/41-53852-B36B9055 for ; Wed, 18 Mar 2015 12:30:35 -0500 Received: by wixw10 with SMTP id w10so46223431wix.0 for ; Wed, 18 Mar 2015 10:30:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=opF6ClrxdncdKDVjFcETW57HD52/uhXabrjoilUCPa0=; b=s0bficGfjmLOZfqbXejXMXPBHSNT7shdofiwpSQluBVyAh3EvicUJ6dJZpMmgniTVO ybzvRo6vjeRfuCjpNeBPZZpXDsmZrs67bqn8vc1rwgowerSKtnajazSmaxfJrgI5P20u Y8KAM+tycazx8AnBAP9x3bwtVfKX53KLNNjGD+4FXxvApTTyb9YLLDb7stlwfgqZgGQo qNfdJpGDxprk2kL5PJH9JegPE1Ycy8nOldfJJU7/gXBz7+UIEuyU0xRE92tdtgudBWEa J+vLPTZLbsnkZt44s2ZZ1hYgLEopiIRDd+9vxv//vUdmKDQhmHqT6dHnWvl9WtS3HzVu UA2w== MIME-Version: 1.0 X-Received: by 10.194.121.136 with SMTP id lk8mr138407929wjb.49.1426699831784; Wed, 18 Mar 2015 10:30:31 -0700 (PDT) Sender: are.you.winning@gmail.com Received: by 10.180.109.233 with HTTP; Wed, 18 Mar 2015 10:30:31 -0700 (PDT) In-Reply-To: References: Date: Wed, 18 Mar 2015 17:30:31 +0000 X-Google-Sender-Auth: aocCmtDusGO_xtUT8-k1fC2TCvc Message-ID: To: Lazare Inepologlou Cc: =?UTF-8?Q?Pavel_Kou=C5=99il?= , Nikita Nefedov , PHP internals Content-Type: multipart/alternative; boundary=089e01227f42acbb330511937015 Subject: Re: [PHP-DEV] [RFC][Accepted] Scalar Type Declarations V0.5 From: cw@daverandom.com (Chris Wright) --089e01227f42acbb330511937015 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 18 March 2015 at 17:07, Lazare Inepologlou wrote: > > 2015-03-18 16:28 GMT+01:00 Chris Wright : > >> On 18 March 2015 at 13:12, Pavel Kou=C5=99il wrote: >> >> > On Wed, Mar 18, 2015 at 2:02 PM, Nikita Nefedov >> > wrote: >> > > On 18 Mar 2015 15:52, "Pavel Kou=C5=99il" wrote= : >> > >> >> > >> Hello, >> > >> >> > >> I made that conclusion because in the first example, the library >> kinda >> > >> forces strict mode rules on the caller, even if he doesn't want to >> use >> > >> strict mode - this makes the interoperability of the two modes >> > >> problematic. >> > > >> > > This is incorrect, library force itself to use right types, not you.= I >> > don't >> > > see any problems here. The only thing that for sure lacks in PHP and >> that >> > > would make STH better is callable signature types. >> > > >> > >> > Well, it forces you to do that, basically. And also forces you to >> > "care" about the mode of library, adding mental overhead. Look more >> > closesly at the first example - does the error in that case make sense >> > to you (from purely user's point of view)? When you call >> > a(function(int $b) {return $b * 2; }) - should you really be required >> > to check the context within the a() is declared? >> > >> >> You don't need to check the declaration context of a(). Either the libra= ry >> is definitely passing an integer and your code will work, or it isn't >> definitely passing an integer, maybe it's a float, so you shouldn't >> declare >> the parameter type at all - it isn't a typed parameter. This is simply a >> matter of RTFM in the library docs (and if there are no docs or the docs >> are wrong then you have to go read the library code anyway just as you >> would today, so you haven't lost anything). >> >> Type declarations are a way to more completely describe the interface >> contract, they are *not* a replacement/shorthand for casts. If the desir= ed >> behaviour for your callback should be to accept anything and treat it as >> an >> integer for the computation, then your code should be written to describ= e >> that intent, i.e: >> >> a(function($b) {return ((int)$b) * 2; }) >> >> This code both describes the behaviour of a() and the programmer's >> intended >> behaviour for the callback. Using a type declaration as a means to force= a >> cast hides both of these - a reader would assume the callback is always >> called with an integer. >> >> > Yet, this code has a major flaw: the type of $b cannot be statically > inferred. > > No matter how "strict" the new mode is, it can only catch errors at > runtime. This is usually too late. Having the ability to find error at > design time is priceless. For me, this is the primary reason I am using > type hints. > > In the case where the caller may or may not be passing an int (i.e. the case where the original example would error because of strict mode in the lib), the type cannot be inferred through static analysis no matter what you do, at least not correctly, because it has no definite type. Since there is currently no "number" union type it is "mixed", which is the default "type" for any variable. > > > Lazare INEPOLOGLOU > Ing=C3=A9nieur Logiciel > > > > >> >> > >> > >> Also, the other possible outcome of the scenario (respecting the mo= de >> > >> of the place where the callback is declared), is IMHO problematic a= s >> > >> well, because it does not respect the strict mode of the place wher= e >> > >> it is called, making it inconsistent with how the dual mode RFC wor= ks >> > >> in general. >> > > >> > > It doesn't matter where the callback or function was declared, it on= ly >> > > matters where it was called. It pretty much is consistent. >> > >> > This was just a comment about how it would be (also) wrong to solve it >> > the other way around. >> > >> > -- >> > PHP Internals - PHP Runtime Development Mailing List >> > To unsubscribe, visit: http://www.php.net/unsub.php >> > >> > >> > > --089e01227f42acbb330511937015--