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authorbculkin2442 <bjculkin@mix.wvu.edu>2019-07-02 18:05:22 -0400
committerbculkin2442 <bjculkin@mix.wvu.edu>2019-07-02 18:05:22 -0400
commit843329de434bb334d90927c4d22345373a388530 (patch)
treeb0ad1f764bd29ff43841e1095a5b58194c20cb37 /src/main/java/bjc/data/Pair.java
parentac36f171a3cebb0993cc28548635e3f654f8e325 (diff)
Rename package root
The package root is now bjc, not io.github.bculkin2442.
Diffstat (limited to 'src/main/java/bjc/data/Pair.java')
-rw-r--r--src/main/java/bjc/data/Pair.java142
1 files changed, 142 insertions, 0 deletions
diff --git a/src/main/java/bjc/data/Pair.java b/src/main/java/bjc/data/Pair.java
new file mode 100644
index 0000000..3c1b7b5
--- /dev/null
+++ b/src/main/java/bjc/data/Pair.java
@@ -0,0 +1,142 @@
+package bjc.data;
+
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+/**
+ * A pair of values, with nothing special about them.
+ *
+ * @author ben
+ *
+ * @param <LeftType>
+ * The type of the left value.
+ *
+ * @param <RightType>
+ * The type of the right value.
+ */
+public class Pair<LeftType, RightType> implements IPair<LeftType, RightType> {
+ /* The left value. */
+ private LeftType leftValue;
+ /* The right value. */
+ private RightType rightValue;
+
+ /** Create a new pair with both sides set to null. */
+ public Pair() {
+
+ }
+
+ /**
+ * Create a new pair with both sides set to the specified values.
+ *
+ * @param left
+ * The value of the left side.
+ *
+ * @param right
+ * The value of the right side.
+ */
+ public Pair(final LeftType left, final RightType right) {
+ leftValue = left;
+ rightValue = right;
+ }
+
+ @Override
+ public <BoundLeft, BoundRight> IPair<BoundLeft, BoundRight> bind(
+ final BiFunction<LeftType, RightType, IPair<BoundLeft, BoundRight>> binder) {
+ if(binder == null) throw new NullPointerException("Binder must not be null.");
+
+ return binder.apply(leftValue, rightValue);
+ }
+
+ @Override
+ public <BoundLeft> IPair<BoundLeft, RightType> bindLeft(
+ final Function<LeftType, IPair<BoundLeft, RightType>> leftBinder) {
+ if(leftBinder == null) throw new NullPointerException("Binder must not be null");
+
+ return leftBinder.apply(leftValue);
+ }
+
+ @Override
+ public <BoundRight> IPair<LeftType, BoundRight> bindRight(
+ final Function<RightType, IPair<LeftType, BoundRight>> rightBinder) {
+ if(rightBinder == null) throw new NullPointerException("Binder must not be null");
+
+ return rightBinder.apply(rightValue);
+ }
+
+ @Override
+ public <OtherLeft, OtherRight, CombinedLeft, CombinedRight> IPair<CombinedLeft, CombinedRight> combine(
+ final IPair<OtherLeft, OtherRight> otherPair,
+ final BiFunction<LeftType, OtherLeft, CombinedLeft> leftCombiner,
+ final BiFunction<RightType, OtherRight, CombinedRight> rightCombiner) {
+ return otherPair.bind((otherLeft, otherRight) -> {
+ final CombinedLeft left = leftCombiner.apply(leftValue, otherLeft);
+ final CombinedRight right = rightCombiner.apply(rightValue, otherRight);
+
+ return new Pair<>(left, right);
+ });
+ }
+
+ @Override
+ public <NewLeft> IPair<NewLeft, RightType> mapLeft(final Function<LeftType, NewLeft> mapper) {
+ if(mapper == null) throw new NullPointerException("Mapper must not be null");
+
+ return new Pair<>(mapper.apply(leftValue), rightValue);
+ }
+
+ @Override
+ public <NewRight> IPair<LeftType, NewRight> mapRight(final Function<RightType, NewRight> mapper) {
+ if(mapper == null) throw new NullPointerException("Mapper must not be null");
+
+ return new Pair<>(leftValue, mapper.apply(rightValue));
+ }
+
+ @Override
+ public <MergedType> MergedType merge(final BiFunction<LeftType, RightType, MergedType> merger) {
+ if(merger == null) throw new NullPointerException("Merger must not be null");
+
+ return merger.apply(leftValue, rightValue);
+ }
+
+ @Override
+ public String toString() {
+ return String.format("Pair [leftValue='%s', rightValue='%s']", leftValue, rightValue);
+ }
+
+ public LeftType getLeft() {
+ return leftValue;
+ }
+
+ public RightType getRight() {
+ return rightValue;
+ }
+
+ @Override
+ public int hashCode() {
+ final int prime = 31;
+ int result = 1;
+
+ result = prime * result + (leftValue == null ? 0 : leftValue.hashCode());
+ result = prime * result + (rightValue == null ? 0 : rightValue.hashCode());
+
+ return result;
+ }
+
+ @Override
+ public boolean equals(final Object obj) {
+ if(this == obj) return true;
+ if(obj == null) return false;
+ if(!(obj instanceof Pair<?, ?>)) return false;
+
+ final Pair<?, ?> other = (Pair<?, ?>) obj;
+
+ if(leftValue == null) {
+ if(other.leftValue != null) return false;
+ } else if(!leftValue.equals(other.leftValue)) return false;
+
+ if(rightValue == null) {
+ if(other.rightValue != null) return false;
+ } else if(!rightValue.equals(other.rightValue)) return false;
+
+ return true;
+ }
+}