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Re: Why only public methods on interfaces?

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On 4/8/2011 7:17 AM, Peter Duniho wrote:
> On 4/8/11 6:59 AM, Patricia Shanahan wrote:
>> [...]
>>>> Yes, but then the implementing methods do have to be public, which is
>>>> undesirable if they should not be used outside the package.
>>>
>>> The implementing type doesn't have to be public either.
>>
>> How do you know that? Of course, implementing the interface does not
>> require it to be public, but the class may also be part of the public
>> face of the package.
>
> Since it's an implementation choice, you can just as easily choose to
> implement the interface in a non-public class.

Yes, it is often possible to work around the public-methods-only
limitation, in several different ways, including a non-public inner
class object that implements the interface on behalf of its surrounding
class.

Interfaces would have been even more useful than they are now if it were
not necessary to work around the limitation.

The really unfortunate decision is not the public methods only, but the
decision to make non-specification of access mean public interface
method declarations but package access in class method declarations.
That cuts off any possibility of changing interfaces now to make them
more flexible.

Patricia

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Why only public methods on interfaces? kramer31 <kramer.newsreader@gmail.com> - 2011-04-07 17:09 -0700
  Re: Why only public methods on interfaces? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-07 21:48 -0300
  Re: Why only public methods on interfaces? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-04-07 21:01 -0400
    Re: Why only public methods on interfaces? v_borchert@despammed.com (Volker Borchert) - 2011-04-08 02:43 +0000
      Re: Why only public methods on interfaces? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-04-08 00:24 -0400
  Re: Why only public methods on interfaces? Patricia Shanahan <pats@acm.org> - 2011-04-07 21:49 -0700
    Re: Why only public methods on interfaces? Owen Jacobson <angrybaldguy@gmail.com> - 2011-04-08 01:01 -0400
      Re: Why only public methods on interfaces? Patricia Shanahan <pats@acm.org> - 2011-04-07 22:37 -0700
        Re: Why only public methods on interfaces? Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-04-08 00:14 -0700
          Re: Why only public methods on interfaces? Patricia Shanahan <pats@acm.org> - 2011-04-08 06:59 -0700
            Re: Why only public methods on interfaces? Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-04-08 07:17 -0700
              Re: Why only public methods on interfaces? Patricia Shanahan <pats@acm.org> - 2011-04-08 08:59 -0700
                Re: Why only public methods on interfaces? Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-04-08 17:27 -0700
                Re: Why only public methods on interfaces? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-04-09 22:14 -0700
                Re: Why only public methods on interfaces? "Mike Schilling" <mscottschilling@hotmail.com> - 2011-04-09 22:28 -0700
                Re: Why only public methods on interfaces? Tom Anderson <twic@urchin.earth.li> - 2011-04-10 16:02 +0100
  Re: Why only public methods on interfaces? Roedy Green <see_website@mindprod.com.invalid> - 2011-04-08 03:18 -0700
    Re: Why only public methods on interfaces? Esmond Pitt <esmond.pitt@bigpond.com> - 2011-04-08 20:32 +1000
  Re: Why only public methods on interfaces? Tom Anderson <twic@urchin.earth.li> - 2011-04-08 20:34 +0100
  Re: Why only public methods on interfaces? Tom Anderson <twic@urchin.earth.li> - 2011-04-10 18:10 +0100

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