vavr's either (#2180)

* moving jmh into libraries module

* refactoring jmh

* Update pom.xml

* manual algorightm

* with BM result

* fix for space issue

* Fixed indentation

* change as per suggestion

* vavr either

* adding unit test and othe rutilities

vavr/src/main/java/com/baeldung/vavr/either/EitherDemo.java

@@ -0,0 +1,90 @@
+package com.baeldung.vavr.either;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import io.vavr.control.Either;
+
+public class EitherDemo {
+
+	public static Object[] computeWithoutEitherUsingArray(int marks) {
+		Object[] results = new Object[2];
+		if (marks < 85) {
+			results[0] = "Marks not acceptable";
+		} else {
+			results[1] = marks;
+		}
+		return results;
+	}
+
+	public static Map<String, Object> computeWithoutEitherUsingMap(int marks) {
+		Map<String, Object> results = new HashMap<String, Object>();
+		if (marks < 85) {
+			results.put("FAILURE", "Marks not acceptable");
+		} else {
+			results.put("SUCCESS", marks);
+		}
+		return results;
+	}
+
+	public static Either<String, Integer> computeWithEither(int marks) {
+		if (marks < 85) {
+			return Either.left("Marks not acceptable");
+		} else {
+			return Either.right(marks);
+		}
+	}
+
+	public static String getError(Either<String, Integer> result) {
+		return result.getLeft();
+	}
+
+	public static int getMarks(Either<String, Integer> result) {
+		return result.get();
+	}
+
+	public static int getModifiedMarks(Either<String, Integer> result) {
+		result = result.right().map(i -> i * 2).toEither();
+		return result.get();
+	}
+
+	public void utilities() {
+
+		String error;
+		int marks;
+
+		Either<String, Integer> result = computeWithEither(100);
+
+		result.toArray();
+		result.toCharSeq();
+		result.toLinkedSet();
+		result.toList();
+		result.toOption();
+		result.toPriorityQueue();
+		result.iterator();
+		result.toVector();
+		result.toTree();
+		result.toStream();
+
+		result.toJavaArray();
+		result.toJavaList();
+		result.toJavaOptional();
+		result.toJavaParallelStream();
+		result.toJavaSet();
+		result.toJavaStream();
+		result.toJavaList();
+
+		Either.RightProjection<String, Integer> projection = computeWithEither(9).right();
+
+		result.contains(800);
+		result.isLeft();
+		result.isRight();
+
+		if (result.isLeft()) {
+			error = result.getLeft();
+		} else {
+			marks = result.get();
+		}
+	}
+
+}

vavr/src/test/java/com/baeldung/vavr/either/EitherUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.vavr.either;
+
+import org.junit.Test;
+
+import io.vavr.control.Either;
+
+import static org.junit.Assert.assertEquals;
+
+public class EitherUnitTest {
+
+	@Test
+	public void givenMarks_whenPassNumber_thenExpectNumber() {
+		Either<String, Integer> result = EitherDemo.computeWithEither(100);
+		int marks = EitherDemo.getMarks(result);
+		assertEquals(100, marks);
+	}
+
+	@Test
+	public void givenMarks_whenFailNumber_thenExpectErrorMesssage() {
+		Either<String, Integer> result = EitherDemo.computeWithEither(50);
+		String error = EitherDemo.getError(result);
+		assertEquals("Marks not acceptable", error);
+	}
+
+	@Test
+	public void givenPassMarks_whenModified_thenExpectNumber() {
+		Either<String, Integer> result = EitherDemo.computeWithEither(90);
+		int marks = EitherDemo.getModifiedMarks(result);
+		assertEquals(180, marks);
+	}
+
+}