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Groups > comp.lang.java.programmer > #3940
| From | Arved Sandstrom <asandstrom3minus1@eastlink.ca> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: "Program to an interface" - When to break a design pattern |
| References | (9 earlier) <JLnxp.68858$yp3.49687@newsfe09.iad> <iq68h6$7og$1@dont-email.me> <whAxp.19939$Ot6.2301@newsfe15.iad> <iq6l21$vuh$1@dont-email.me> <iqbihl$40p$1@dont-email.me> |
| Message-ID | <Ysjyp.13$jc2.12@newsfe11.iad> (permalink) |
| Organization | Public Usenet Newsgroup Access |
| Date | 2011-05-10 20:01 -0300 |
On 11-05-10 11:36 AM, markspace wrote: > On 5/8/2011 10:48 AM, Daniele Futtorovic wrote: > >> This is perhaps the sixth time I've written the same thing with a >> different wording. If it still doesn't get through to anyone, then yes, >> I'll declare pearls before swine. Sorry for not being 'diplomatic' more >> than the first half a dozen tries. > > No, I think you're right, if I've been following the discussion properly > (it's gone a bit long winded). > > As an example, here's a method in the Java API that returns an array -- > something with NO constraints on data order -- and yet the docs for the > method say the order is guaranteed. > > <http://download.oracle.com/javase/6/docs/api/java/lang/Class.html#getEnumConstants%28%29> > > It's even a relatively recently added method too, not some historical > oddity. So I agree it's legit to document, but not enforce by type, > ordering or other invariants on the objects a method returns. > Well, the usefulness of the debate for me is that I have been forced to more accurately describe the situation where I believe that use of LinkedHashMap, vice the Map, is, if not preferable, at least not to be vilified and rejected. To wit, we'd be dealing with non-published implementation code where the designer/implementer requires strong guarantees, in code, that no other Map will be used. I think a few people are getting that I'm being _that_ specific, but still think that documentation is a better approach. That's fine - I am personally wary, through experience, of relying on other people to read comments and Javadocs, but YMMV. With all due respect to Daniele, I find it difficult to characterize him as being right when he says (in a previous post): ""Now Map tells you very little". [ed. quote from me] This is the central point. As I have argued all along, it tells you /no less/ than it being LinkedHashMap, because, as you have acknowledged, the mere fact that the return type is LinkedHashMap does not give you any conclusive insight into its iteration order (predictability thereof)." I'm sorry, he and I are seriously at odds over what predictability means here (and quite frankly, what the LinkedHashMap Javadoc means by using the term). And I sure as hell didn't acknowledge what he says I "acknowledged" about LinkedHashMap and its predictability. As the OP pointed out, his *user* - the person who entered the data and is now viewing it, knows exactly what the insertion order was, and expects to see it kept. LinkedHashMap provides that guarantee of predictability to the *user* here, as the OP explained - Map does not. I agree that _declaring_ the return type as LinkedHashMap does not achieve that; the ironclad knowledge that it _is_ LinkedHashMap does, even if it's declared as Map. But in some cases (see above) there is no harm, and arguably some utility, in making the explicit declaration. That's the point I've been trying to make. Evidently I'm running into the "program to an interface at all costs" principle. AHS
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"Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-05 12:21 -0700
Re: "Program to an interface" - When to break a design pattern Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-05 15:43 -0400
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-05 17:19 -0400
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-05 21:47 +0200
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 14:14 -0600
Re: "Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-05 13:26 -0700
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-05 22:27 +0200
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 14:42 -0600
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-05 22:48 +0200
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 15:02 -0600
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 00:02 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-05 19:49 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 02:28 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-06 07:24 -0300
Re: "Program to an interface" - When to break a design pattern Patricia Shanahan <pats@acm.org> - 2011-05-06 07:03 -0700
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-06 17:30 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 18:56 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-06 17:50 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 23:37 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-06 19:43 -0300
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 17:17 -0600
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 02:28 +0200
Re: "Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-05 23:25 -0700
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-06 18:25 +0200
Re: "Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-07 16:26 -0700
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-08 03:28 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-08 00:05 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-08 16:15 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-08 14:20 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-08 19:48 +0200
Re: "Program to an interface" - When to break a design pattern markspace <-@.> - 2011-05-10 07:36 -0700
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-10 13:04 -0600
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-10 21:31 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-10 20:01 -0300
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-11 19:14 +0200
Re: "Program to an interface" - When to break a design pattern Patricia Shanahan <pats@acm.org> - 2011-05-11 10:41 -0700
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-11 19:55 +0200
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-11 16:42 -0400
Re: "Program to an interface" - When to break a design pattern Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-05-11 23:34 +0200
Re: "Program to an interface" - When to break a design pattern "John B. Matthews" <nospam@nospam.invalid> - 2011-05-12 00:51 -0400
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-12 00:58 -0400
Re: "Program to an interface" - When to break a design pattern Tom Anderson <twic@urchin.earth.li> - 2011-05-12 20:08 +0100
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-15 13:25 -0300
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-05 17:24 -0400
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 16:00 -0600
Re: "Program to an interface" - When to break a design pattern Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2011-05-06 15:01 +0300
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-06 12:17 -0400
Re: "Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-07 16:28 -0700
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-05 17:21 -0400
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 15:58 -0600
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-05 18:18 -0400
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-05 19:20 -0300
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-05 18:23 -0400
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-05 20:17 -0300
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-05 18:26 -0300
Re: "Program to an interface" - When to break a design pattern Steven Simpson <ss@domain.invalid> - 2011-05-05 22:57 +0100
Re: "Program to an interface" - When to break a design pattern Tom Anderson <twic@urchin.earth.li> - 2011-05-05 23:29 +0100
Re: "Program to an interface" - When to break a design pattern Steven Simpson <ss@domain.invalid> - 2011-05-06 13:30 +0100
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-06 12:19 -0400
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 16:41 -0600
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-05 20:47 -0300
Re: "Program to an interface" - When to break a design pattern Roedy Green <see_website@mindprod.com.invalid> - 2011-05-05 16:41 -0700
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-05 22:47 -0600
Re: "Program to an interface" - When to break a design pattern Zapanaz <http://joecosby.com/code/mail.pl@foo.com> - 2011-05-05 23:28 -0700
Re: "Program to an interface" - When to break a design pattern Michal Kleczek <kleku75@gmail.com> - 2011-05-06 17:15 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-06 20:53 -0300
Re: "Program to an interface" - When to break a design pattern Lew <noone@lewscanon.com> - 2011-05-06 21:39 -0400
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-07 00:56 -0300
Re: "Program to an interface" - When to break a design pattern Michal Kleczek <kleku75@gmail.com> - 2011-05-08 12:24 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-08 13:42 -0300
Re: "Program to an interface" - When to break a design pattern Michal Kleczek <kleku75@gmail.com> - 2011-05-09 11:04 +0200
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-09 19:33 -0300
Re: "Program to an interface" - When to break a design pattern Michal Kleczek <kleku75@gmail.com> - 2011-05-10 15:51 +0200
Re: "Program to an interface" - When to break a design pattern Jim Janney <jjanney@shell.xmission.com> - 2011-05-10 13:15 -0600
Re: "Program to an interface" - When to break a design pattern Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-05-10 19:40 -0300
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