java-either

Do you know https://hackage.haskell.org/package/base-4.7.0.0/docs/Data-Either.html? So this is the crippled Java version of it.

It's on Maven Central

<dependency>
  <groupId>de.scravy</groupId>
  <artifactId>either</artifactId>
  <version>1.0.0</version>
</dependency>

It's easy

final Either<String, Exception> value = Either.left("Hello World!");
if (value.isLeft()) {
    System.out.println(value.getLeft());
}

-or-

final Either<String, Exception> value = Either.left("Hello World!");
if (value instanceof Either.Left) {
    System.out.println(value.getLeft());
}

It's free

MIT License.