Added interface to JDK collector API

6 files changed, 242 insertions, 6 deletions

diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/BoundLazyPair.java b/BJC-Utils2/src/main/java/bjc/utils/data/BoundLazyPair.java
index 1635e06..dcf9cca 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/BoundLazyPair.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/BoundLazyPair.java
@@ -26,8 +26,8 @@ class BoundLazyPair<OldLeft, OldRight, NewLeft, NewRight>
 	@Override
 	public <BoundLeft, BoundRight> IPair<BoundLeft, BoundRight> bind(
 			BiFunction<NewLeft, NewRight, IPair<BoundLeft, BoundRight>> bindr) {
-		IHolder<IPair<NewLeft, NewRight>> newPair = new Identity<>(
-				boundPair);
+		IHolder<IPair<NewLeft, NewRight>> newPair =
+				new Identity<>(boundPair);
 		IHolder<Boolean> newPairMade = new Identity<>(pairBound);
 
 		Supplier<NewLeft> leftSupp = () -> {
@@ -93,8 +93,8 @@ class BoundLazyPair<OldLeft, OldRight, NewLeft, NewRight>
 	public <MergedType> MergedType
 			merge(BiFunction<NewLeft, NewRight, MergedType> merger) {
 		if (!pairBound) {
-			boundPair = binder.apply(leftSupplier.get(),
-					rightSupplier.get());
+			boundPair =
+					binder.apply(leftSupplier.get(), rightSupplier.get());
 
 			pairBound = true;
 		}
@@ -166,4 +166,19 @@ class BoundLazyPair<OldLeft, OldRight, NewLeft, NewRight>
 
 		return new LazyPair<>(leftSupp, rightSupp);
 	}
+
+	@Override
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<NewLeft, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<NewRight, OtherRight, CombinedRight> rightCombiner) {
+		return otherPair.bind((otherLeft, otherRight) -> {
+			return bind((leftVal, rightVal) -> {
+				return new LazyPair<>(
+						leftCombiner.apply(leftVal, otherLeft),
+						rightCombiner.apply(rightVal, otherRight));
+			});
+		});
+	}
 }
\ No newline at end of file
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/Either.java b/BJC-Utils2/src/main/java/bjc/utils/data/Either.java
new file mode 100644
index 0000000..8787888
--- /dev/null
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/Either.java
@@ -0,0 +1,135 @@
+package bjc.utils.data;
+
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+/**
+ * Represents a pair where only one side has a value
+ * 
+ * @author ben
+ * @param <LeftType>
+ *            The type that could be on the left
+ * @param <RightType>
+ *            The type that could be on the right
+ *
+ */
+public class Either<LeftType, RightType>
+		implements IPair<LeftType, RightType> {
+	private LeftType	leftVal;
+	private RightType	rightVal;
+
+	private boolean		isLeft;
+
+	private Either(LeftType left, RightType right) {
+		if (left == null) {
+			rightVal = right;
+		} else {
+			leftVal = left;
+
+			isLeft = true;
+		}
+	}
+
+	/**
+	 * Create a new either with the left value occupied
+	 * 
+	 * @param <LeftType>
+	 *            The type of the left value
+	 * @param <RightType>
+	 *            The type of the empty right value
+	 * @param left
+	 *            The value to put on the left
+	 * @return An either with the left side occupied
+	 */
+	public static <LeftType, RightType> Either<LeftType, RightType>
+			fromLeft(LeftType left) {
+		return new Either<>(left, null);
+	}
+
+	/**
+	 * Create a new either with the right value occupied
+	 * 
+	 * @param <LeftType>
+	 *            The type of the empty left value
+	 * @param <RightType>
+	 *            The type of the right value
+	 * @param right
+	 *            The value to put on the right
+	 * @return An either with the right side occupied
+	 */
+	public static <LeftType, RightType> Either<LeftType, RightType>
+			fromRight(RightType right) {
+		return new Either<>(null, right);
+	}
+
+	@Override
+	public <BoundLeft, BoundRight> IPair<BoundLeft, BoundRight> bind(
+			BiFunction<LeftType, RightType, IPair<BoundLeft, BoundRight>> binder) {
+		return binder.apply(leftVal, rightVal);
+	}
+
+	@Override
+	public <BoundLeft> IPair<BoundLeft, RightType> bindLeft(
+			Function<LeftType, IPair<BoundLeft, RightType>> leftBinder) {
+		if (isLeft) {
+			return leftBinder.apply(leftVal);
+		}
+
+		return new Either<>(null, rightVal);
+	}
+
+	@Override
+	public <BoundRight> IPair<LeftType, BoundRight> bindRight(
+			Function<RightType, IPair<LeftType, BoundRight>> rightBinder) {
+		if (isLeft) {
+			return new Either<>(leftVal, null);
+		}
+
+		return rightBinder.apply(rightVal);
+	}
+
+	@Override
+	public <NewLeft> IPair<NewLeft, RightType>
+			mapLeft(Function<LeftType, NewLeft> mapper) {
+		if (isLeft) {
+			return new Either<>(mapper.apply(leftVal), null);
+		}
+
+		return new Either<>(null, rightVal);
+	}
+
+	@Override
+	public <NewRight> IPair<LeftType, NewRight>
+			mapRight(Function<RightType, NewRight> mapper) {
+		if (isLeft) {
+			return new Either<>(leftVal, null);
+		}
+
+		return new Either<>(null, mapper.apply(rightVal));
+	}
+
+	@Override
+	public <MergedType> MergedType
+			merge(BiFunction<LeftType, RightType, MergedType> merger) {
+		return merger.apply(leftVal, rightVal);
+	}
+
+	@Override
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<LeftType, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<RightType, OtherRight, CombinedRight> rightCombiner) {
+		if (isLeft) {
+			return otherPair.bind((otherLeft, otherRight) -> {
+				return new Either<>(leftCombiner.apply(leftVal, otherLeft),
+						null);
+			});
+		}
+
+		return otherPair.bind((otherLeft, otherRight) -> {
+			return new Either<>(null,
+					rightCombiner.apply(rightVal, otherRight));
+		});
+	}
+}
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/HalfBoundLazyPair.java b/BJC-Utils2/src/main/java/bjc/utils/data/HalfBoundLazyPair.java
index 9e26924..198dd96 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/HalfBoundLazyPair.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/HalfBoundLazyPair.java
@@ -138,4 +138,19 @@ class HalfBoundLazyPair<OldType, NewLeft, NewRight>
 
 		return new LazyPair<>(leftSupp, rightSupp);
 	}
+	
+	@Override
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<NewLeft, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<NewRight, OtherRight, CombinedRight> rightCombiner) {
+		return otherPair.bind((otherLeft, otherRight) -> {
+			return bind((leftVal, rightVal) -> {
+				return new LazyPair<>(
+						leftCombiner.apply(leftVal, otherLeft),
+						rightCombiner.apply(rightVal, otherRight));
+			});
+		});
+	}
 }
\ No newline at end of file
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/IPair.java b/BJC-Utils2/src/main/java/bjc/utils/data/IPair.java
index 707724b..f94d656 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/IPair.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/IPair.java
@@ -81,7 +81,8 @@ public interface IPair<LeftType, RightType>
 						"This function can only be applied to instances of IPair");
 			}
 
-			IPair<OldLeft, OldRight> argPair = (IPair<OldLeft, OldRight>) argumentPair;
+			IPair<OldLeft, OldRight> argPair =
+					(IPair<OldLeft, OldRight>) argumentPair;
 
 			return argPair.mapLeft(func);
 		};
@@ -98,7 +99,8 @@ public interface IPair<LeftType, RightType>
 						"This function can only be applied to instances of IPair");
 			}
 
-			IPair<OldLeft, OldRight> argPair = (IPair<OldLeft, OldRight>) argumentPair;
+			IPair<OldLeft, OldRight> argPair =
+					(IPair<OldLeft, OldRight>) argumentPair;
 
 			return argPair.mapRight(func);
 		};
@@ -163,4 +165,46 @@ public interface IPair<LeftType, RightType>
 	 */
 	public <MergedType> MergedType
 			merge(BiFunction<LeftType, RightType, MergedType> merger);
+
+	/**
+	 * Combine the contents of two pairs together
+	 * 
+	 * @param <OtherLeft>
+	 *            The type of the left value of the other pair
+	 * @param <OtherRight>
+	 *            The type of the right value of the other pair
+	 * @param <CombinedLeft>
+	 *            The type of the left value of the combined pair
+	 * @param <CombinedRight>
+	 *            The type of the right value of the combined pair
+	 * @param otherPair
+	 *            The other pair to combine with
+	 * @param leftCombiner
+	 * @param rightCombiner
+	 * @return A pair with its values combined
+	 */
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<LeftType, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<RightType, OtherRight, CombinedRight> rightCombiner);
+
+	/**
+	 * Pairwise combine two pairs together
+	 * 
+	 * @param <OtherLeft>
+	 *            The left type of the other pair
+	 * @param <OtherRight>
+	 *            The right type of the other pair
+	 * @param otherPair
+	 *            The pair to combine with
+	 * @return The pairs, pairwise combined together
+	 */
+	public default <OtherLeft, OtherRight>
+			IPair<IPair<LeftType, OtherLeft>, IPair<RightType, OtherRight>>
+			combine(IPair<OtherLeft, OtherRight> otherPair) {
+		return combine(otherPair,
+				(left, otherLeft) -> new Pair<>(left, otherLeft),
+				(right, otherRight) -> new Pair<>(right, otherRight));
+	}
 }
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/LazyPair.java b/BJC-Utils2/src/main/java/bjc/utils/data/LazyPair.java
index 6f1be10..d688e5b 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/LazyPair.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/LazyPair.java
@@ -198,4 +198,19 @@ public class LazyPair<LeftType, RightType>
 
 		return new LazyPair<>(leftSupp, rightSupp);
 	}
+
+	@Override
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<LeftType, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<RightType, OtherRight, CombinedRight> rightCombiner) {
+		return otherPair.bind((otherLeft, otherRight) -> {
+			return bind((leftVal, rightVal) -> {
+				return new LazyPair<>(
+						leftCombiner.apply(leftVal, otherLeft),
+						rightCombiner.apply(rightVal, otherRight));
+			});
+		});
+	}
 }
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/Pair.java b/BJC-Utils2/src/main/java/bjc/utils/data/Pair.java
index eb421bc..1fc0d19 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/Pair.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/Pair.java
@@ -104,4 +104,16 @@ public class Pair<LeftType, RightType>
 
 		return new Pair<>(leftValue, mapper.apply(rightValue));
 	}
+
+	@Override
+	public <OtherLeft, OtherRight, CombinedLeft, CombinedRight>
+			IPair<CombinedLeft, CombinedRight>
+			combine(IPair<OtherLeft, OtherRight> otherPair,
+					BiFunction<LeftType, OtherLeft, CombinedLeft> leftCombiner,
+					BiFunction<RightType, OtherRight, CombinedRight> rightCombiner) {
+		return otherPair.bind((otherLeft, otherRight) -> {
+			return new Pair<>(leftCombiner.apply(leftValue, otherLeft),
+					rightCombiner.apply(rightValue, otherRight));
+		});
+	}
 }
\ No newline at end of file