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From: Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: "Program to an interface" - When to break a design pattern
Date: Wed, 11 May 2011 19:55:17 +0200
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On 11/05/2011 19:41, Patricia Shanahan allegedly wrote:
> I think some of the trouble might lie in the ambiguity, in a Java
> context, of the sentence "Program to an interface.".
>
> Meaning 1: Users of some module (in the widest sense) should depend only
> on what is declared and specified about the module, not on direct
> knowledge of how it is currently implemented.
>
> Meaning 2: Java programs should depend only in Java interface types to
> represent what is declared and specified about a module for the use of
> its callers.
>
> I am very strongly in favor of meaning 1 of "Program to an interface.".
> Everything any user of a module needs to know about it should be
> declared and/or specified as part of its interface (in the general
> sense), and using code should depend only on what is declared and
> specified.

Absolutely. Isn't the wording "program to a contract rather to an 
implementation" also in use? I find that a much better one, because it 
doesn't evoke Java interfaces.

-- 
DF.
An escaped convict once said to me:
"Alcatraz is the place to be"