From 843329de434bb334d90927c4d22345373a388530 Mon Sep 17 00:00:00 2001 From: bculkin2442 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/Pair.java | 142 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 src/main/java/bjc/data/Pair.java (limited to 'src/main/java/bjc/data/Pair.java') 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 + * The type of the left value. + * + * @param + * The type of the right value. + */ +public class Pair implements IPair { + /* 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 IPair bind( + final BiFunction> binder) { + if(binder == null) throw new NullPointerException("Binder must not be null."); + + return binder.apply(leftValue, rightValue); + } + + @Override + public IPair bindLeft( + final Function> leftBinder) { + if(leftBinder == null) throw new NullPointerException("Binder must not be null"); + + return leftBinder.apply(leftValue); + } + + @Override + public IPair bindRight( + final Function> rightBinder) { + if(rightBinder == null) throw new NullPointerException("Binder must not be null"); + + return rightBinder.apply(rightValue); + } + + @Override + public IPair combine( + final IPair otherPair, + final BiFunction leftCombiner, + final BiFunction 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 IPair mapLeft(final Function mapper) { + if(mapper == null) throw new NullPointerException("Mapper must not be null"); + + return new Pair<>(mapper.apply(leftValue), rightValue); + } + + @Override + public IPair mapRight(final Function mapper) { + if(mapper == null) throw new NullPointerException("Mapper must not be null"); + + return new Pair<>(leftValue, mapper.apply(rightValue)); + } + + @Override + public MergedType merge(final BiFunction 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; + } +} -- cgit v1.2.3