iluwatar#1842 Improved example

Author: hkattt-anu

currying/src/main/java/com/iluwatar/currying/App.java

@@ -22,38 +22,13 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-/*
-* 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.currying;
 
 import java.time.LocalDate;
 
 /**
 * This is a Javadoc comment to pass the style check.
 */
-
 public class App {
   /**
   * This is a Javadoc comment to pass the style check.
@@ -69,13 +44,9 @@ public static void main(String[] args) {
     Book.AddTitle kingHorrorBooksFunc = horrorBookFunc.withAuthor("Stephen King");
     Book.AddTitle rowlingFantasyBooksFunc = fantasyBookFunc.withAuthor("J.K. Rowling");
 
-    // Creates horror books by Stephen King
+    // Creates books by Stephen King (horror and fantasy genres)
     Book shining = kingHorrorBooksFunc.withTitle("The Shining")
             .withPublicationDate(LocalDate.of(1977, 1, 28));
-    Book it = kingHorrorBooksFunc.withTitle("It")
-            .withPublicationDate(LocalDate.of(1986, 9, 15));
-
-    // Creates fantasy books by Stephen King
     Book darkTower = kingFantasyBooksFunc.withTitle("The Dark Tower: Gunslinger")
             .withPublicationDate(LocalDate.of(1982, 6, 10));
 
@@ -91,10 +62,14 @@ public static void main(String[] args) {
             .withTitle("Foundation")
             .withPublicationDate(LocalDate.of(1942, 5, 1));
 
+    System.out.println("Stephen King Books:");
     System.out.println(shining);
-    System.out.println(it);
     System.out.println(darkTower);
+
+    System.out.println("J.K. Rowling Books:");
     System.out.println(chamberOfSecrets);
+
+    System.out.println("Sci-fi Books:");
     System.out.println(dune);
     System.out.println(foundation);
   }

currying/src/main/java/com/iluwatar/currying/Book.java

@@ -32,24 +32,18 @@
  * This is a Javadoc comment to pass the style check.
  */
 public class Book {
-  private Genre genre;
-  private String author;
-  private String title;
-  private LocalDate publicationDate;
+  private final Genre genre;
+  private final String author;
+  private final String title;
+  private final LocalDate publicationDate;
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   Book(Genre genre, String author, String title, LocalDate publicationDate) {
     this.genre = genre;
     this.author = author;
     this.title = title;
     this.publicationDate = publicationDate;
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   @Override
   public boolean equals(Object o) {
     if (this == o) {
@@ -65,25 +59,19 @@ public boolean equals(Object o) {
             && Objects.equals(publicationDate, book.publicationDate);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   @Override
   public int hashCode() {
     return Objects.hash(author, genre, title, publicationDate);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   @Override
   public String toString() {
     return "Book{" + "genre=" + genre + ", author='" + author + '\''
             + ", title='" + title + '\'' + ", publicationDate=" + publicationDate + '}';
   }
 
   /**
-   * This is a Javadoc comment to pass the style check.
+   * Curried unary book create functions.
    */
   static Function<Genre, Function<String, Function<String, Function<LocalDate, Book>>>> BOOK_CREATOR = //
       genre
@@ -93,7 +81,8 @@ public String toString() {
                       -> new Book(genre, author, title, publicationDate);
 
   /**
-   * This is a Javadoc comment to pass the style check.
+   * Implements the builder pattern using functional interfaces to create a more readable
+   * book creator function.
    */
   public static AddGenre builder() {
     return genre
@@ -103,30 +92,18 @@ public static AddGenre builder() {
                     -> new Book(genre, author, title, publicationDate);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   public interface AddGenre {
     Book.AddAuthor withGenre(Genre genre);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   public interface AddAuthor {
     Book.AddTitle withAuthor(String author);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   public interface AddTitle {
     Book.AddPublicationDate withTitle(String title);
   }
 
-  /**
-   * This is a Javadoc comment to pass the style check.
-   */
   public interface AddPublicationDate {
     Book withPublicationDate(LocalDate publicationDate);
   }