Some notes on Elvis and Other Null-Safe Operators

[Schulz, Stefan]

Joseph D. Darcy wrote:
> Mark Mahieu wrote:
> > Elvis operator can be approximated as a library method:
> >
> >          static <T> T elvis(T t1, T t2) { return t1 != null 
> ? t1 : t2; }
> >
> > In a core-libs round table recording (at 
> http://mail.openjdk.java.net/ 
> > pipermail/core-libs-dev/2009-April/001406.html) the possibility of  
> > adding core library methods for common null-handling tasks is  
> > mentioned, such as throwing a standard exception if a supplied  
> > argument is null (presumably similar to methods in  
> > com.google.common.base.Preconditions).  Is it reasonable to 
> implement  
> > the Elvis operator as a language change but other null-handling  
> > facilities as library changes?
> >   
> 
> A belated reply, in general and for null handling in particular, 
> addressing the problem with libraries is preferable to addressing the 
> problem with a language change.
> 
> -Joe

Just as a side note: while such a library based solution for elvis is formally possible, without some closure like construct, the advantage of evaluating the RHS expression on demand only will be lost.

Cheers, Stefan