Peculiar fruits in the JDK

[David M. Lloyd]

On 06/25/2008 03:57 AM, Ulf Zibis wrote:
> Hi David,
> 
> can you show an example using a 'switch' statement which is shorter or 
> faster than:
> 
>            char c = c2bMap.charAt(c2bMapIndex[(current & MASK1) >> 
> SHIFT] + (current & MASK2));

Faster - maybe or maybe not; but the "c2bMap", being sparse, can be 
represented possibly more space-efficiently using a lookupswitch (I'm 
thinking of all the \u0000 entries, which can be handled with a "default" 
branch):

     public static final c2bMapper(int idx) {
         switch (idx) {
             case 1: return 1;
             case 2: return 2;
             ...
             default: return 0;
         }
     }

The primary disadvantage being, I guess, that the table cannot then be 
stored in e.g. a properties file.

- DML