Initial Jack import.

Change-Id: I953cf0a520195a7187d791b2885848ad0d5a9b43

1 files changed, 91 insertions, 0 deletions

diff --git a/guava/src/com/google/common/collect/TransformedImmutableSet.java b/guava/src/com/google/common/collect/TransformedImmutableSet.java
new file mode 100644
index 0000000..a6a59c9
--- /dev/null
+++ b/guava/src/com/google/common/collect/TransformedImmutableSet.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.common.collect;
+
+import com.google.common.annotations.GwtCompatible;
+import com.google.common.annotations.GwtIncompatible;
+
+import java.util.Iterator;
+
+/**
+ * An {@code ImmutableSet} whose elements are derived by transforming another collection's elements,
+ * useful for {@code ImmutableMap.keySet()}.
+ *
+ * @author Jesse Wilson
+ */
+@GwtCompatible(emulated = true)
+abstract class TransformedImmutableSet<D, E> extends ImmutableSet<E> {
+  /*
+   * TODO(cpovirk): using an abstract source() method instead of a field could simplify
+   * ImmutableMapKeySet, which currently has to pass in entrySet() manually
+   */
+  final ImmutableCollection<D> source;
+  final int hashCode;
+
+  TransformedImmutableSet(ImmutableCollection<D> source) {
+    this.source = source;
+    this.hashCode = Sets.hashCodeImpl(this);
+  }
+
+  TransformedImmutableSet(ImmutableCollection<D> source, int hashCode) {
+    this.source = source;
+    this.hashCode = hashCode;
+  }
+
+  abstract E transform(D element);
+
+  @Override
+  public int size() {
+    return source.size();
+  }
+
+  @Override public boolean isEmpty() {
+    return false;
+  }
+
+  @Override public UnmodifiableIterator<E> iterator() {
+    final Iterator<D> backingIterator = source.iterator();
+    return new UnmodifiableIterator<E>() {
+      @Override
+      public boolean hasNext() {
+        return backingIterator.hasNext();
+      }
+
+      @Override
+      public E next() {
+        return transform(backingIterator.next());
+      }
+    };
+  }
+
+  @Override public Object[] toArray() {
+    return toArray(new Object[size()]);
+  }
+
+  @Override public <T> T[] toArray(T[] array) {
+    return ObjectArrays.toArrayImpl(this, array);
+  }
+
+  @Override public final int hashCode() {
+    return hashCode;
+  }
+
+  @GwtIncompatible("unused")
+  @Override boolean isHashCodeFast() {
+    return true;
+  }
+}