introduce bitloops

src/test/java/puzzle/ExportFormatTest.java

@@ -85,8 +85,7 @@ public class ExportFormatTest {
    
    @Test
    void testExportFormatEmpty() {
-      var swe          = new SwedishGenerator(new Rng(0), new int[STACK_SIZE], Clues.createEmpty());
+      var grid         = SwedishGeneratorTest.createEmpty();
-      var grid         = Grid.createEmpty();
       val clues        = Clues.createEmpty();
       var fillResult   = new FillResult(true, new Gridded(grid), new long[300], new FillStats(0, 0, 0, 0));
       var puzzleResult = new PuzzleResult(new Clued(clues), fillResult);

src/test/java/puzzle/SwedishGeneratorTest.java

@@ -12,6 +12,7 @@ import static puzzle.SwedishGenerator.*;
 
 public class SwedishGeneratorTest {
    
+   static Grid createEmpty() { return new Grid(new byte[SIZE], X, X); }
    record Context(long[] bitset) {
       
       public Context() { this(new long[2500]); }
@@ -76,7 +77,7 @@ public class SwedishGeneratorTest {
    static final byte D_BYTE_2 = CLUE_RIGHT;
    @Test
    void testPatternForSlotAllLetters() {
-      var grid    = new Grid(new byte[]{ LETTER_A, LETTER_B, LETTER_C });
+      var grid    = new Grid(new byte[]{ LETTER_A, LETTER_B, LETTER_C }, 0, 0);
       var slot    = Slot.from(18 << Slot.BIT_FOR_DIR | (CLUE_RIGHT), 7L, 0L);
       var pattern = patternForSlot(grid, slot);
       
@@ -85,7 +86,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testPatternForSlotMixed() {
-      var grid    = new Grid(new byte[]{ LETTER_A, DASH, LETTER_C });
+      var grid    = new Grid(new byte[]{ LETTER_A, DASH, LETTER_C }, 0, 0);
       var slot    = Slot.from(1 << Slot.BIT_FOR_DIR | (CLUE_RIGHT), 7L, 0L);
       var pattern = patternForSlot(grid, slot);
       
@@ -94,7 +95,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testPatternForSlotAllDashes() {
-      var grid    = new Grid(new byte[]{ DASH, DASH, DASH }); // - - -
+      var grid    = new Grid(new byte[]{ DASH, DASH, DASH }, 0, 0); // - - -
       var slot    = Slot.from(1 << Slot.BIT_FOR_DIR | (CLUE_RIGHT), 7L, 0L);
       var pattern = patternForSlot(grid, slot);
       
@@ -103,7 +104,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testPatternForSlotSingleLetter() {
-      var grid    = new Grid(new byte[]{ LETTER_A, DASH, DASH });
+      var grid    = new Grid(new byte[]{ LETTER_A, DASH, DASH }, 0, 0);
       var slot    = Slot.from(1 << Slot.BIT_FOR_DIR | (CLUE_RIGHT), 7L, 0L);
       var pattern = patternForSlot(grid, slot);
       
@@ -129,7 +130,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testGrid() {
-      var grid = Grid.createEmpty();
+      var grid = createEmpty();
       grid.setLetter(OFF_0_0, LETTER_A);
       assertEquals('A', grid.letter32At(OFF_0_0));
    }
@@ -322,7 +323,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testPlaceWord() {
-      var grid = Grid.createEmpty();
+      var grid = createEmpty();
       // Slot at OFF_0_0 length 3, horizontal (right)
       var key        = (OFF_0_0 << Slot.BIT_FOR_DIR) | (CLUE_RIGHT);
       var lo         = (1L << OFF_0_0) | (1L << OFF_0_1) | (1L << OFF_0_2);
@@ -350,7 +351,7 @@ public class SwedishGeneratorTest {
       assertEquals('C', grid.letter32At(OFF_0_2));
       
       // 4. Partial placement then conflict (rollback)
-      grid = Grid.createEmpty();
+      grid = createEmpty();
       grid.setLetter(OFF_0_2, LETTER_X); // Conflict at the end
       assertFalse(placeWord(grid, s, w1, undoBuffer, 3));
       // Verify grid is still empty (except for 'X')
@@ -361,7 +362,7 @@ public class SwedishGeneratorTest {
    
    @Test
    void testBacktrackingHelpers() {
-      var grid = Grid.createEmpty();
+      var grid = createEmpty();
       // Slot at 0,1 length 2
       var key        = (OFF_0_0 << Slot.BIT_FOR_DIR) | (CLUE_RIGHT);
       var lo         = (1L << OFF_0_1) | (1L << OFF_0_2);