dummy argument to return



Sometimes it nerves me to introduce a dummy argument to return from a loop.

e.g.

(%i1) (i:1, do ( i:i+1, if i=21 then return('dummy_argument) ), 2*i);
(%o1)                                 42

I do not use the return value here. I'd rather would like to write 

(i:1, do ( i:i+1, if i=21 then return() ), 2*i);

I would like to see that return() is allowed. In that case do should return done as well or false 
according to an empty argument.

Comments?

Where is this mechanism defined? Tracing didn't help me very much. I guess there happens 
a caught throw.

Volker van Nek