| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.lib.rules.objc; |
| |
| import com.google.common.base.Function; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.Iterables; |
| |
| /** |
| * Utility code for interspersing items into sequences. |
| */ |
| public class Interspersing { |
| private Interspersing() {} |
| |
| /** |
| * Inserts {@code what} before each item in {@code sequence}, returning a lazy sequence of twice |
| * the length. |
| */ |
| public static <E> Iterable<E> beforeEach(final E what, Iterable<E> sequence) { |
| Preconditions.checkNotNull(what); |
| return Iterables.concat( |
| Iterables.transform(sequence, element -> ImmutableList.of(what, element))); |
| } |
| |
| /** |
| * Prepends {@code what} to each string in {@code sequence}, returning a lazy sequence of the |
| * same length. |
| */ |
| public static Iterable<String> |
| prependEach(final String what, Iterable<String> sequence) { |
| Preconditions.checkNotNull(what); |
| return Iterables.transform(sequence, input -> what + input); |
| } |
| |
| /** |
| * Similar to {@link #prependEach(String, Iterable)}, but also converts each item in the sequence |
| * to a string. |
| */ |
| public static <E> Iterable<String> |
| prependEach(String what, Iterable<E> sequence, Function<? super E, String> toString) { |
| return prependEach(what, Iterables.transform(sequence, toString)); |
| } |
| } |