refactor: rename fluent interface module

fluent-interface/src/main/java/com/iluwatar/fluentinterface/app/App.java

@@ -0,0 +1,131 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * 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 NONINFRINGEMENT. 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 com.iluwatar.fluentinterface.app;
+
+import com.iluwatar.fluentinterface.fluentiterable.FluentIterable;
+import com.iluwatar.fluentinterface.fluentiterable.lazy.LazyFluentIterable;
+import com.iluwatar.fluentinterface.fluentiterable.simple.SimpleFluentIterable;
+import java.util.List;
+import java.util.StringJoiner;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * The Fluent Interface pattern is useful when you want to provide an easy readable, flowing API.
+ * Those interfaces tend to mimic domain specific languages, so they can nearly be read as human
+ * languages.
+ *
+ * <p>In this example two implementations of a {@link FluentIterable} interface are given. The
+ * {@link SimpleFluentIterable} evaluates eagerly and would be too costly for real world
+ * applications. The {@link LazyFluentIterable} is evaluated on termination. Their usage is
+ * demonstrated with a simple number list that is filtered, transformed and collected. The result is
+ * printed afterward.
+ */
+@Slf4j
+public class App {
+
+  /**
+   * Program entry point.
+   */
+  public static void main(String[] args) {
+
+    var integerList = List.of(1, -61, 14, -22, 18, -87, 6, 64, -82, 26, -98, 97, 45, 23, 2, -68);
+
+    prettyPrint("The initial list contains: ", integerList);
+
+    var firstFiveNegatives = SimpleFluentIterable
+        .fromCopyOf(integerList)
+        .filter(negatives())
+        .first(3)
+        .asList();
+    prettyPrint("The first three negative values are: ", firstFiveNegatives);
+
+
+    var lastTwoPositives = SimpleFluentIterable
+        .fromCopyOf(integerList)
+        .filter(positives())
+        .last(2)
+        .asList();
+    prettyPrint("The last two positive values are: ", lastTwoPositives);
+
+    SimpleFluentIterable
+        .fromCopyOf(integerList)
+        .filter(number -> number % 2 == 0)
+        .first()
+        .ifPresent(evenNumber -> LOGGER.info("The first even number is: {}", evenNumber));
+
+
+    var transformedList = SimpleFluentIterable
+        .fromCopyOf(integerList)
+        .filter(negatives())
+        .map(transformToString())
+        .asList();
+    prettyPrint("A string-mapped list of negative numbers contains: ", transformedList);
+
+
+    var lastTwoOfFirstFourStringMapped = LazyFluentIterable
+        .from(integerList)
+        .filter(positives())
+        .first(4)
+        .last(2)
+        .map(number -> "String[" + number + "]")
+        .asList();
+    prettyPrint("The lazy list contains the last two of the first four positive numbers "
+        + "mapped to Strings: ", lastTwoOfFirstFourStringMapped);
+
+    LazyFluentIterable
+        .from(integerList)
+        .filter(negatives())
+        .first(2)
+        .last()
+        .ifPresent(number -> LOGGER.info("Last amongst first two negatives: {}", number));
+  }
+
+  private static Function<Integer, String> transformToString() {
+    return integer -> "String[" + integer + "]";
+  }
+
+  private static Predicate<? super Integer> negatives() {
+    return integer -> integer < 0;
+  }
+
+  private static Predicate<? super Integer> positives() {
+    return integer -> integer > 0;
+  }
+
+  private static <E> void prettyPrint(String prefix, Iterable<E> iterable) {
+    prettyPrint(", ", prefix, iterable);
+  }
+
+  private static <E> void prettyPrint(
+      String delimiter, String prefix,
+      Iterable<E> iterable
+  ) {
+    var joiner = new StringJoiner(delimiter, prefix, ".");
+    iterable.forEach(e -> joiner.add(e.toString()));
+    LOGGER.info(joiner.toString());
+  }
+}