1 files changed, 35 insertions, 0 deletions
diff --git a/src/main/java/au/id/zancanaro/Generators.java b/src/main/java/au/id/zancanaro/Generators.java
new file mode 100644
index 0000000..f065d1d
--- /dev/null
+++ b/src/main/java/au/id/zancanaro/Generators.java
@@ -0,0 +1,35 @@
+package au.id.zancanaro;
+
+import java.util.Iterator;
+
+public class Generators {
+    @SafeVarargs
+    public static <T> Generator<T[]> arrayGenerator(Generator<? extends T>... generators) {
+        return Generator.tuple((Generator<T>[]) generators);
+    }
+
+    public static Generator<Integer> integerGenerator() {
+        return (random, size) -> {
+            int value = random.nextInt(size);
+            return new RoseTree<>(value, intShrinkingIterable(value));
+        };
+    }
+
+    private static Iterable<RoseTree<Integer>> intShrinkingIterable(final int value) {
+        return () -> new Iterator<RoseTree<Integer>>() {
+            int curr = value;
+
+            @Override
+            public boolean hasNext() {
+                return curr > 0;
+            }
+
+            @Override
+            public RoseTree<Integer> next() {
+                int prevCurr = curr;
+                curr = curr / 2;
+                return new RoseTree<>(value - prevCurr, intShrinkingIterable(value - prevCurr));
+            }
+        };
+    }
+}