Merge branch '__rultor'

src/main/java/org/cactoos/scalar/Folded.java

@@ -38,6 +38,28 @@
  * ).value() // returns 10L
  * </pre>
  *
+ * <p>Here is how you can use it to
+ * find one of items according to the specified {@link BiFunc}:</p>
+ *
+ * <pre>
+ *  final String apple = new Folded&lt;&gt;(
+ *          (first, last) -&gt; first,
+ *          new IterableOf&lt;Scalar&lt;String&gt;&gt;(
+ *              () -&gt; "Apple",
+ *              () -&gt; "Banana",
+ *              () -&gt; "Orange"
+ *          )
+ *      ).value();
+ *  final String orange = new Folded&lt;&gt;(
+ *          (first, last) -&gt; last,
+ *          new IterableOf&lt;Scalar&lt;String&gt;&gt;(
+ *              () -&gt; "Apple",
+ *              () -&gt; "Banana",
+ *              () -&gt; "Orange"
+ *          )
+ *      ).value();
+ * </pre>
+ *
  * <p>There is no thread-safety guarantee.
  *
  * <p>This class implements {@link Scalar}, which throws a checked
@@ -49,7 +71,7 @@
  * @author Eduard Balovnev (bedward70@mail.ru)
  * @version $Id$
  * @param <T> Scalar type
- * @since 0.9
+ * @since 0.29
  */
 public final class Folded<T> implements Scalar<T> {
 

src/main/java/org/cactoos/scalar/LowestOf.java

@@ -0,0 +1,114 @@
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2018 Yegor Bugayenko
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+package org.cactoos.scalar;
+
+import org.cactoos.Scalar;
+import org.cactoos.iterable.IterableOf;
+import org.cactoos.iterable.Mapped;
+
+/**
+ * Find the lowest item.
+ *
+ * <p>Here is how you can use it to
+ * find lowest of {@link Comparable} items:</p>
+ *
+ * <pre>
+ * final String lowest = new LowestOf&lt;String&gt;(
+ *         () -&gt; "Banana", () -&gt; "Apple", () -&gt; "Orange"
+ *     ).value();
+ * // -&gt; lowest == "Apple"
+ *
+ * final Character lowestChar = new LowestOf&lt;&gt;('B', 'U', 'G').value();
+ * // -&gt; lowestChar == 'B'
+ * </pre>
+ *
+ * <p>This class implements {@link Scalar}, which throws a checked
+ * {@link Exception}. This may not be convenient in many cases. To make
+ * it more convenient and get rid of the checked exception you can
+ * use {@link UncheckedScalar} or {@link IoCheckedScalar} decorators.</p>
+ *
+ * <p>There is no thread-safety guarantee.
+ *
+ * @author Fabricio Cabral (fabriciofx@gmail.com)
+ * @author Eduard Balovnev (bedward70@mail.ru)
+ * @version $Id$
+ * @param <T> Scalar type
+ * @see UncheckedScalar
+ * @see IoCheckedScalar
+ * @since 0.29
+ */
+public final class LowestOf<T extends Comparable<T>> implements Scalar<T> {
+
+    /**
+     * Result.
+     */
+    private final Scalar<T> result;
+
+    /**
+     * Ctor.
+     * @param items The comparable items
+     */
+    @SafeVarargs
+    public LowestOf(final T... items) {
+        this(
+            new Mapped<>(
+                item -> () -> item,
+                items
+            )
+        );
+    }
+
+    /**
+     * Ctor.
+     * @param scalars The scalars
+     */
+    @SafeVarargs
+    public LowestOf(final Scalar<T>... scalars) {
+        this(new IterableOf<>(scalars));
+    }
+
+    /**
+     * Ctor.
+     * @param iterable The items
+     */
+    public LowestOf(final Iterable<Scalar<T>> iterable) {
+        this.result = new Folded<>(
+            (first, second) -> {
+                final T value;
+                if (first.compareTo(second) < 0) {
+                    value = first;
+                } else {
+                    value = second;
+                }
+                return value;
+            },
+            iterable
+        );
+    }
+
+    @Override
+    public T value() throws Exception {
+        return this.result.value();
+    }
+}

src/test/java/org/cactoos/scalar/FoldedTest.java

@@ -36,7 +36,7 @@
  *
  * @author Eduard Balovnev (bedward70@mail.ru)
  * @version $Id$
- * @since 1.0
+ * @since 0.29
  * @checkstyle JavadocMethodCheck (500 lines)
  */
 public final class FoldedTest {
@@ -46,8 +46,7 @@ public void failsForEmptyIterable() throws Exception {
         new Folded<>(
             (first, last) -> first,
             Collections.emptyList()
-        )
-            .value();
+        ).value();
     }
 
     @Test