Hi Sebb, sebb wrote:
> On 7 October 2011 21:53, <simonetrip...@apache.org> wrote: >> Author: simonetripodi >> Date: Fri Oct 7 20:53:25 2011 >> New Revision: 1180231 >> >> URL: http://svn.apache.org/viewvc?rev=1180231&view=rev >> Log: >> '4' is a magic number. > > Agreed. > >> Modified: >> commons/proper/functor/trunk/src/main/java/org/apache/commons/functor/core/composite/UnaryCompositeBinaryFunction.java >> >> Modified: >> commons/proper/functor/trunk/src/main/java/org/apache/commons/functor/core/composite/UnaryCompositeBinaryFunction.java >> URL: >> http://svn.apache.org/viewvc/commons/proper/functor/trunk/src/main/java/org/apache/commons/functor/core/composite/UnaryCompositeBinaryFunction.java?rev=1180231&r1=1180230&r2=1180231&view=diff >> ============================================================================== >> --- >> commons/proper/functor/trunk/src/main/java/org/apache/commons/functor/core/composite/UnaryCompositeBinaryFunction.java >> (original) +++ >> commons/proper/functor/trunk/src/main/java/org/apache/commons/functor/core/composite/UnaryCompositeBinaryFunction.java >> Fri Oct 7 20:53:25 2011 @@ -48,6 +48,9 @@ public class >> UnaryCompositeBinaryFunctio */ private static final long serialVersionUID >> = 264219357293822629L; >> >> + /** Base hash integer used to shift hash. */ >> + private static final int HASH_SHIFT = 4; >> + > > We know what it is used for, but why choose 4 rather than 3 or 42 or 1? > > Is it arbitrary? If so, what is the possible range? > If not arbitrary, why choose 4? Kidding? An int has 32 bits in Java. Shifting by 42 gives ... 0 :D So you should not use a very high number, because you will lose bits at the upper end. What I am always wondering more, is why losing bits at all, simply use the rolling shift operation: hash >>>= HASH_SHIFT; [snip] - Jörg --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
