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mperrymperry
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Merge pull request #277 from bakeemawaytoys/Issue_276
2 parents 9e5b6ad + 0330824 commit 9e70768

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‎quickcheck/src/main/java/fj/test/Shrink.java‎

Lines changed: 23 additions & 24 deletions
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@@ -39,6 +39,8 @@
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import static fj.data.Stream.nil;
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import static java.lang.System.arraycopy;
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import static java.math.BigInteger.ZERO;
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import java.math.BigDecimal;
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import java.math.BigInteger;
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import java.sql.Time;
@@ -354,7 +356,7 @@ public static <A> Shrink<ArrayList<A>> shrinkArrayList(final Shrink<A> sa) {
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* A shrink strategy for enum maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for enum maps.
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*/
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public static <K extends Enum<K>, V> Shrink<EnumMap<K, V>> shrinkEnumMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -385,7 +387,7 @@ public static <A extends Enum<A>> Shrink<EnumSet<A>> shrinkEnumSet(final Shrink<
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* A shrink strategy for hash maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for hash maps.
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*/
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public static <K, V> Shrink<HashMap<K, V>> shrinkHashMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -406,7 +408,7 @@ public static <A> Shrink<HashSet<A>> shrinkHashSet(final Shrink<A> sa) {
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* A shrink strategy for hash tables.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for hash tables.
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*/
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@SuppressWarnings("UseOfObsoleteCollectionType")
@@ -430,7 +432,7 @@ public static <K, V> Shrink<Hashtable<K, V>> shrinkHashtable(final Shrink<K> sk,
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* A shrink strategy for identity hash maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for identity hash maps.
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*/
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public static <K, V> Shrink<IdentityHashMap<K, V>> shrinkIdentityHashMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -441,7 +443,7 @@ public static <K, V> Shrink<IdentityHashMap<K, V>> shrinkIdentityHashMap(final S
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* A shrink strategy for linked hash maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for linked hash maps.
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*/
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public static <K, V> Shrink<LinkedHashMap<K, V>> shrinkLinkedHashMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -514,7 +516,7 @@ public static <A> Shrink<Stack<A>> shrinkStack(final Shrink<A> sa) {
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* A shrink strategy for tree maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for tree maps.
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*/
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public static <K, V> Shrink<TreeMap<K, V>> shrinkTreeMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -545,7 +547,7 @@ public static <A> Shrink<Vector<A>> shrinkVector(final Shrink<A> sa) {
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* A shrink strategy for weak hash maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for weak hash maps.
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*/
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public static <K, V> Shrink<WeakHashMap<K, V>> shrinkWeakHashMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -570,7 +572,7 @@ public static <A> Shrink<ArrayBlockingQueue<A>> shrinkArrayBlockingQueue(final S
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* A shrink strategy for concurrent hash maps.
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*
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* @param sk The shrink strategy for keys.
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* @param sv The shrink stratgey for values.
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* @param sv The shrink strategy for values.
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* @return A shrink strategy for concurrent hash maps.
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*/
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public static <K, V> Shrink<ConcurrentHashMap<K, V>> shrinkConcurrentHashMap(final Shrink<K> sk, final Shrink<V> sv) {
@@ -676,23 +678,20 @@ public static <A> Shrink<SynchronousQueue<A>> shrinkSynchronousQueue(final Shrin
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/**
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* A shrink strategy for big integers.
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*/
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public static final Shrink<BigInteger> shrinkBigInteger =
680-
shrinkP2(shrinkByte, shrinkArray(shrinkByte)).map(bs -> {
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final byte[] x = new byte[bs._2().length() + 1];
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for (int i = 0; i < bs._2().array().length; i++) {
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x[i] = bs._2().get(i);
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}
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x[bs._2().length()] = bs._1();
681+
public static final Shrink<BigInteger> shrinkBigInteger = shrink(i -> {
682+
final Equal<BigInteger> eq = Equal.bigintEqual;
683+
final BigInteger two = BigInteger.valueOf(2L);
684+
if (eq.eq(i, ZERO)) {
685+
return nil();
686+
} else {
687+
final Stream<BigInteger> is = cons(ZERO,
688+
() -> iterate(x -> x.divide(two), i)
689+
.takeWhile(x2 -> eq.notEq(x2, ZERO))
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.map(i::subtract));
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689-
return new BigInteger(x);
690-
}, i -> {
691-
final byte[] b = i.toByteArray();
692-
final Byte[] x = new Byte[b.length - 1];
693-
arraycopy(b, 0, x, 0, b.length - 1);
694-
return p(b[0], array(x));
695-
});
692+
return Ord.bigintOrd.isLessThan(i, ZERO) ? cons(i.negate(), () -> is) : is;
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}
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});
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/**
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* A shrink strategy for big decimals.

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