Feature Request: Improved detection of Singleton variables

Dear all,

the detection of singleton variables by the ECLiPSe compiler is useful in
finding bugs.  But sometimes this mechanism fails to find such variables.
Consider the following example:

test(A, B, V1) :-
        
    (A == B ->
       V2 = 'yes'
    ;
       V2 = 'no'
    ),
    writeln(V1).

Variable V2 is never used twice, thus could be called a singleton variable.  
Unfortunately, V2 is not detected as such.

I just experienced such a bug (typo + copy&paste) buried deep in a system.
Took me a while to find it.


The detection of such singleton variables would be a valuable extension.


Regards, Uli    
-- 
Ulrich Scholz            

Personal Memory Group                   
European Media Laboratory GmbH