introduce bitloops

src/main/java/puzzle/SwedishGenerator.java

@@ -27,8 +27,6 @@ import static java.nio.charset.StandardCharsets.*;
  * A) generate randoms for and idx and direction (clue together)
  * B) convert IDX_PATH_0_BASE into bit-pattern (i think) Length should not be checked, just left empty if not good.
  * C) store more information in the byte[] even consider the long[] or try sqeeze the 288 options (clue) in a byte.
- * D) separate clue into three long pairs of hi and lo, (v,h,r) so we do not store the clue anymore in the grid array at all
- * E) store letter-set also in a long pair so we can use it in path determinations
  * F) pre-determine random clue arrangements, so they do not involve impossible clue's such as bottom at last or the line before that and such to all sides
  * G) Check 3wall, the current implementation may be faster, but the accuracy is lower, degrade performance on the filler
  */
@@ -391,11 +389,8 @@ public record SwedishGenerator(Rng rng, int[] stack, Clues cache) {
       static Slot from(int key, long lo, long hi)   { return new Slot(key, lo, hi); }
       
       public int length()                           { return Long.bitCount(lo) + Long.bitCount(hi); }
-      public int clueIndex()                        { return clueIndex(key); }
       public static int clueIndex(int key)          { return key >>> BIT_FOR_DIR; }
       public static int dir(int key)                { return key & 3; }
-      public boolean horiz()                        { return horiz(key); }
-      public boolean increasing()                   { return (key & 2) == 0; }
       public static boolean increasing(int dir)     { return (dir & 2) == 0; }
       public IntStream walk()                       { return Gridded.walk((byte) key, lo, hi); }
       public static boolean horiz(int d)            { return (d & 1) != 0; }