Add Function3

...and rename ExceptionUtils to FunctionalUtils as the old name
would no longer be appropriate.

Test: FrameworksNetTests
Change-Id: I2affd69fb84d7f250b4a45497eec6c052bf6ec50

staticlibs/testutils/devicetests/com/android/testutils/TestPermissionUtil.kt

@@ -20,8 +20,8 @@ package com.android.testutils
 
 import androidx.test.platform.app.InstrumentationRegistry
 import com.android.modules.utils.build.SdkLevel
-import com.android.testutils.ExceptionUtils.ThrowingRunnable
-import com.android.testutils.ExceptionUtils.ThrowingSupplier
+import com.android.testutils.FunctionalUtils.ThrowingRunnable
+import com.android.testutils.FunctionalUtils.ThrowingSupplier
 
 /**
  * Run the specified [task] with the specified [permissions] obtained through shell

staticlibs/testutils/hostdevice/com/android/testutils/Cleanup.kt

@@ -18,8 +18,8 @@
 
 package com.android.testutils
 
-import com.android.testutils.ExceptionUtils.ThrowingRunnable
-import com.android.testutils.ExceptionUtils.ThrowingSupplier
+import com.android.testutils.FunctionalUtils.ThrowingRunnable
+import com.android.testutils.FunctionalUtils.ThrowingSupplier
 import javax.annotation.CheckReturnValue
 
 /**

staticlibs/testutils/hostdevice/com/android/testutils/FunctionalUtils.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * 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.android.testutils;
+
+import java.util.function.Supplier;
+
+/**
+ * A class grouping some utilities to deal with exceptions.
+ */
+public class FunctionalUtils {
+    /**
+     * Like a Consumer, but declared to throw an exception.
+     * @param <T>
+     */
+    @FunctionalInterface
+    public interface ThrowingConsumer<T> {
+        /** @see java.util.function.Consumer */
+        void accept(T t) throws Exception;
+    }
+
+    /**
+     * Like a Supplier, but declared to throw an exception.
+     * @param <T>
+     */
+    @FunctionalInterface
+    public interface ThrowingSupplier<T> {
+        /** @see java.util.function.Supplier */
+        T get() throws Exception;
+    }
+
+    /**
+     * Like a Runnable, but declared to throw an exception.
+     */
+    @FunctionalInterface
+    public interface ThrowingRunnable {
+        /** @see java.lang.Runnable */
+        void run() throws Exception;
+    }
+
+    /**
+     * Convert a supplier that throws into one that doesn't.
+     *
+     * The returned supplier returns null in cases where the source throws.
+     */
+    public static <T> Supplier<T> ignoreExceptions(ThrowingSupplier<T> func) {
+        return () -> {
+            try {
+                return func.get();
+            } catch (Exception e) {
+                return null;
+            }
+        };
+    }
+
+    /**
+     * Convert a runnable that throws into one that doesn't.
+     *
+     * All exceptions are ignored by the returned Runnable.
+     */
+    public static Runnable ignoreExceptions(ThrowingRunnable r) {
+        return () -> {
+            try {
+                r.run();
+            } catch (Exception e) {
+            }
+        };
+    }
+
+    // Java has Function<T, R> and BiFunction<T, U, V> but nothing for higher-arity functions.
+    // Function3 is what Kotlin and Scala use (they also have higher-arity variants, with
+    // FunctionN taking N arguments, as the JVM does not have variadic formal parameters)
+    /**
+     * A function with three arguments.
+     * @param <TArg1> Type of the first argument
+     * @param <TArg2> Type of the second argument
+     * @param <TArg3> Type of the third argument
+     * @param <TResult> Type of the return value
+     */
+    public interface Function3<TArg1, TArg2, TArg3, TResult> {
+        /**
+         * Apply the function to the arguments
+         */
+        TResult apply(TArg1 a1, TArg2 a2, TArg3 a3);
+    }
+}

staticlibs/testutils/hostdevice/com/android/testutils/MiscAsserts.kt

@@ -18,7 +18,7 @@
 
 package com.android.testutils
 
-import com.android.testutils.ExceptionUtils.ThrowingRunnable
+import com.android.testutils.FunctionalUtils.ThrowingRunnable
 import java.lang.reflect.Modifier
 import kotlin.system.measureTimeMillis
 import kotlin.test.assertEquals