Hello Adam,
On 9/13/07, Adam Winer <[EMAIL PROTECTED]> wrote:
>
> I'm not sure I see the benefit, but I'm not always spot-on
> when it comes to wildcards in collections...
>
> Does the change mean that you're allowed to pass
> a Map<String, String> to this without casting, whereas
> before you couldn't?
Yeah, that's the only benefit. More specifically, it allow the following to
work:
icon.renderIcon(context, rc, Collections.singletonMap("shortDesc", "foo"));
The common use-cases here all
> have a heterogeneous value type (because of "embedded"),
> so if I'm understanding this correctly, I don't see the benefit
> of this change.
>
> (BTW, I thought that in fact was possible to add elements
> to "? super ...", just not "? extends ...".)
Exactly, but it would really makes no sense at all to use super in that
signature imho.
-- Adam
>
>
> On 9/13/07, Simon Lessard <[EMAIL PROTECTED]> wrote:
> > Hello,
> >
> > I would like to do a public API change to Icon's renderIcon method and
> its
> > dependencies. Currently the signature is
> >
> > abstract public void renderIcon(
> > FacesContext context,
> > RenderingContext arc,
> > Map<String, Object> attrs
> > ) throws IOException;
> >
> > I would like to change that to the following to make it easier to call
> > because of non covariance of generic collections.
> >
> > abstract public void renderIcon(
> > FacesContext context,
> > RenderingContext arc,
> > Map<String, ? extends Object> attrs
> > ) throws IOException;
> >
> > I don't think it'll break anything as it's a generalization of the
> previous
> > signature, meaning all old code should still be able to call the method
> > without any change. The only implication is that renderIcon and its
> > dependencies will no longer be able to alter the map since it's quite
> > impossible to add an element to a collection containing a wildcard. It's
> not
> > in the method contract to alter the attribute map though, so it should
> not
> > be an issue. However, as it's a public API change, I preferred to ask on
> the
> > mailing list in case I oversaw something.
> >
> >
> > Regards,
> >
> > ~ Simon
> >
>
