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Implementing Either<Left,Right> in Java

(View current approaches)

(View Test Case with example usage)

(New Approach - Discovery Process)

(New Approach - Implemented in this library)

Instantiation

• Multiples constructors + Parameter Inference + var-args

public final class Either<T1,T2> {
    public enum L { Left }
    public enum R { Right }

    public Either(T1 left , L... _) {/*Omitted*/}
    public Either(T2 right, R... _) {/*Omitted*/}
    /*Omitted*/
}
////////////// In use //////////////
new Either<Integer,String>(2);
new Either<Integer,String>("Text");

Deconstruction

• Matching classes

public final class IntStringMatcher implements Either.Alternative<Integer,String> {
  @Override public void when(Integer value, L... _) {/*Omitted*/}
  @Override public void when(String  value, R... _) {/*Omitted*/}
}
////////////// In use //////////////
Either<Integer,String> e = new Either<Integer,String>("Text");
e.match(new IntStringMatcher());

• Matching classes - Closure

public final class MatcherClosure {
  public MatcherClosure(Either<Integer,String> e) { e.match(new IntStringMatcher()); }

  private final class IntStringMatcher implements Either.Alternative<Integer,String> {
    @Override public void when(Integer value, L... _) {/*Omitted*/}
    @Override public void when(String  value, R... _) {/*Omitted*/}
  }
}
////////////// In use //////////////
Either<Integer,String> e = new Either<Integer,String>(0);
new MatcherClosure(e);