Re: [Vala] Does vala provide syntactic sugar for "weak" references that know when its peer has been nulled?

[Phil Housley <undeconstructed gmail com>]

On 3 March 2010 23:17, Jan Hudec <bulb ucw cz> wrote:
> On Wed, Mar 03, 2010 at 15:22:59 -0600, Sandino Flores Moreno wrote:
> > Is it possible for a weak ref to know when its peer object has been
> > deleted (and then assigned to null)?

> By the way, note that Java and C# don't have any weak references at all.
> Unowned references in vala are mostly optimization to avoid some reference
> coutning or copying that you have to be careful with and can do without. Full
> weak references are obviously useless for that, since setting up the back
> link is more expensive than the reference counting in the first place.

Just for the record, Java does have various reference types, including weak.

For a summary: http://java.sun.com/javase/6/docs/api/java/lang/ref/package-summary.html
For some classes:
http://java.sun.com/javase/6/docs/api/java/lang/ref/Reference.html

Reference.get() is the safe way to get a referenced object - assigning
the result to something strongly references the object and so it is
safe for as long as you need it.

-- 
Phil Housley