diff options
Diffstat (limited to 'src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java')
-rw-r--r-- | src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java b/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java new file mode 100644 index 00000000..1ad516c5 --- /dev/null +++ b/src/main/java/org/whispersystems/libaxolotl/util/guava/Function.java @@ -0,0 +1,61 @@ +/* + * 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 org.whispersystems.libaxolotl.util.guava; + + + +/** + * Determines an output value based on an input value. + * + * <p>See the Guava User Guide article on <a href= + * "http://code.google.com/p/guava-libraries/wiki/FunctionalExplained">the use of {@code + * Function}</a>. + * + * @author Kevin Bourrillion + * @since 2.0 (imported from Google Collections Library) + */ + +public interface Function<F, T> { + /** + * Returns the result of applying this function to {@code input}. This method is <i>generally + * expected</i>, but not absolutely required, to have the following properties: + * + * <ul> + * <li>Its execution does not cause any observable side effects. + * <li>The computation is <i>consistent with equals</i>; that is, {@link Objects#equal + * Objects.equal}{@code (a, b)} implies that {@code Objects.equal(function.apply(a), + * function.apply(b))}. + * </ul> + * + * @throws NullPointerException if {@code input} is null and this function does not accept null + * arguments + */ + T apply(F input); + + /** + * Indicates whether another object is equal to this function. + * + * <p>Most implementations will have no reason to override the behavior of {@link Object#equals}. + * However, an implementation may also choose to return {@code true} whenever {@code object} is a + * {@link Function} that it considers <i>interchangeable</i> with this one. "Interchangeable" + * <i>typically</i> means that {@code Objects.equal(this.apply(f), that.apply(f))} is true for all + * {@code f} of type {@code F}. Note that a {@code false} result from this method does not imply + * that the functions are known <i>not</i> to be interchangeable. + */ + @Override + boolean equals(Object object); +} |