From 843329de434bb334d90927c4d22345373a388530 Mon Sep 17 00:00:00 2001
From: bculkin2442 <bjculkin@mix.wvu.edu>
Date: Tue, 2 Jul 2019 18:05:22 -0400
Subject: Rename package root

The package root is now bjc, not io.github.bculkin2442.
---
 src/main/java/bjc/data/IPair.java | 241 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 241 insertions(+)
 create mode 100644 src/main/java/bjc/data/IPair.java

(limited to 'src/main/java/bjc/data/IPair.java')

diff --git a/src/main/java/bjc/data/IPair.java b/src/main/java/bjc/data/IPair.java
new file mode 100644
index 0000000..0c63f16
--- /dev/null
+++ b/src/main/java/bjc/data/IPair.java
@@ -0,0 +1,241 @@
+package bjc.data;
+
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+import bjc.funcdata.theory.Bifunctor;
+
+/**
+ * Represents a pair of values.
+ *
+ * @author ben
+ *
+ * @param <LeftType>
+ *                The type of the left side of the pair.
+ *
+ * @param <RightType>
+ *                The type of the right side of the pair.
+ *
+ */
+public interface IPair<LeftType, RightType> extends Bifunctor<LeftType, RightType> {
+	/**
+	 * Bind a function across the values in this pair.
+	 *
+	 * @param <BoundLeft>
+	 *                The type of the bound left.
+	 *
+	 * @param <BoundRight>
+	 *                The type of the bound right.
+	 *
+	 * @param binder
+	 *                The function to bind with.
+	 *
+	 * @return The bound pair.
+	 */
+	public <BoundLeft, BoundRight> IPair<BoundLeft, BoundRight> bind(
+			BiFunction<LeftType, RightType, IPair<BoundLeft, BoundRight>> binder);
+
+	/**
+	 * Bind a function to the left value in this pair.
+	 *
+	 * @param <BoundLeft>
+	 *                The type of the bound value.
+	 *
+	 * @param leftBinder
+	 *                The function to use to bind.
+	 *
+	 * @return A pair with the left type bound.
+	 */
+	public <BoundLeft> IPair<BoundLeft, RightType> bindLeft(
+			Function<LeftType, IPair<BoundLeft, RightType>> leftBinder);
+
+	/**
+	 * Bind a function to the right value in this pair.
+	 *
+	 * @param <BoundRight>
+	 *                The type of the bound value.
+	 *
+	 * @param rightBinder
+	 *                The function to use to bind.
+	 *
+	 * @return A pair with the right type bound.
+	 */
+	public <BoundRight> IPair<LeftType, BoundRight> bindRight(
+			Function<RightType, IPair<LeftType, BoundRight>> rightBinder);
+
+	/**
+	 * 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(
+			final IPair<OtherLeft, OtherRight> otherPair) {
+		return combine(otherPair, Pair<LeftType, OtherLeft>::new, Pair<RightType, OtherRight>::new);
+	}
+
+	/**
+	 * 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
+	 *                The function to combine the left values with.
+	 *
+	 * @param rightCombiner
+	 *                The function to combine the right values with.
+	 *
+	 * @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);
+
+	/**
+	 * Immediately perfom the specified action with the contents of this
+	 * pair.
+	 *
+	 * @param consumer
+	 *                The action to perform on the pair.
+	 */
+	public default void doWith(final BiConsumer<LeftType, RightType> consumer) {
+		merge((leftValue, rightValue) -> {
+			consumer.accept(leftValue, rightValue);
+
+			return null;
+		});
+	}
+
+	@Override
+	default <OldLeft, OldRight, NewLeft> LeftBifunctorMap<OldLeft, OldRight, NewLeft> fmapLeft(
+			final Function<OldLeft, NewLeft> func) {
+		return argumentPair -> {
+			if (!(argumentPair instanceof IPair<?, ?>)) {
+				final String msg = "This function can only be applied to instances of IPair";
+
+				throw new IllegalArgumentException(msg);
+			}
+
+			final IPair<OldLeft, OldRight> argPair = (IPair<OldLeft, OldRight>) argumentPair;
+
+			return argPair.mapLeft(func);
+		};
+	}
+
+	@Override
+	default <OldLeft, OldRight, NewRight> RightBifunctorMap<OldLeft, OldRight, NewRight> fmapRight(
+			final Function<OldRight, NewRight> func) {
+		return argumentPair -> {
+			if (!(argumentPair instanceof IPair<?, ?>)) {
+				final String msg = "This function can only be applied to instances of IPair";
+
+				throw new IllegalArgumentException(msg);
+			}
+
+			final IPair<OldLeft, OldRight> argPair = (IPair<OldLeft, OldRight>) argumentPair;
+
+			return argPair.mapRight(func);
+		};
+	}
+
+	/**
+	 * Get the value on the left side of the pair.
+	 *
+	 * @return The value on the left side of the pair.
+	 */
+	@Override
+	public default LeftType getLeft() {
+		return merge((leftValue, rightValue) -> leftValue);
+	}
+
+	/**
+	 * Get the value on the right side of the pair.
+	 *
+	 * @return The value on the right side of the pair.
+	 */
+	@Override
+	public default RightType getRight() {
+		return merge((leftValue, rightValue) -> rightValue);
+	}
+
+	/**
+	 * Transform the value on the left side of the pair.
+	 *
+	 * Doesn't modify the pair.
+	 *
+	 * @param <NewLeft>
+	 *                The new type of the left part of the pair.
+	 *
+	 * @param mapper
+	 *                The function to use to transform the left part of the
+	 *                pair.
+	 *
+	 * @return The pair, with its left part transformed.
+	 */
+	public <NewLeft> IPair<NewLeft, RightType> mapLeft(Function<LeftType, NewLeft> mapper);
+
+	/**
+	 * Transform the value on the right side of the pair.
+	 *
+	 * Doesn't modify the pair.
+	 *
+	 * @param <NewRight>
+	 *                The new type of the right part of the pair.
+	 *
+	 * @param mapper
+	 *                The function to use to transform the right part of the
+	 *                pair.
+	 *
+	 * @return The pair, with its right part transformed.
+	 */
+	public <NewRight> IPair<LeftType, NewRight> mapRight(Function<RightType, NewRight> mapper);
+
+	/**
+	 * Merge the two values in this pair into a single value.
+	 *
+	 * @param <MergedType>
+	 *                The type of the single value.
+	 *
+	 * @param merger
+	 *                The function to use for merging.
+	 *
+	 * @return The pair, merged into a single value.
+	 */
+	public <MergedType> MergedType merge(BiFunction<LeftType, RightType, MergedType> merger);
+
+	/**
+	 * Static pair constructor.
+	 * 
+	 * @param left
+	 *                The left side of the pair.
+	 * @param right
+	 *                The right side of the pair.
+	 * @return A pair, with the specified left/right side.
+	 */
+	public static <T1, T2> IPair<T1, T2> pair(T1 left, T2 right) {
+		return new Pair<>(left, right);
+	}
+}
-- 
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