1 files changed, 41 insertions, 0 deletions
diff --git a/guava/src/com/google/common/util/concurrent/AsyncFunction.java b/guava/src/com/google/common/util/concurrent/AsyncFunction.java
new file mode 100644
index 0000000..441c029
--- /dev/null
+++ b/guava/src/com/google/common/util/concurrent/AsyncFunction.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2011 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.util.concurrent;
+
+import com.google.common.annotations.Beta;
+
+import java.util.concurrent.Future;
+
+/**
+ * Transforms a value, possibly asynchronously. For an example usage and more
+ * information, see {@link Futures#transform(ListenableFuture, AsyncFunction)}.
+ *
+ * @author Chris Povirk
+ * @since 11.0
+ */
+@Beta
+public interface AsyncFunction<I, O> {
+  /**
+   * Returns an output {@code Future} to use in place of the given {@code
+   * input}. The output {@code Future} need not be {@linkplain Future#isDone
+   * done}, making {@code AsyncFunction} suitable for asynchronous derivations.
+   *
+   * <p>Throwing an exception from this method is equivalent to returning a
+   * failing {@code Future}.
+   */
+  ListenableFuture<O> apply(I input) throws Exception;
+}