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package bjc.utils.data;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
/**
* Holds a pair of values of two different types.
*
* Is an eager variant of {@link IPair}
*
* @author ben
*
* @param <L>
* The type of the thing held on the left (first)
* @param <R>
* The type of the thing held on the right (second)
*/
public class Pair<L, R> implements IPair<L, R> {
/**
* The left value of the pair
*/
protected L leftValue;
/**
* The right value of the pair
*/
protected R rightValue;
/**
* Create a new pair that holds two nulls.
*/
public Pair() {
}
/**
* Create a new pair holding the specified values.
*
* @param left
* The value to hold on the left.
* @param right
* The value to hold on the right.
*/
public Pair(L left, R right) {
leftValue = left;
rightValue = right;
}
/*
* (non-Javadoc)
*
* @see bjc.utils.data.IPair#doWith(java.util.function.BiConsumer)
*/
@Override
public void doWith(BiConsumer<L, R> action) {
if (action == null) {
throw new NullPointerException("Action must be non-null");
}
action.accept(leftValue, rightValue);
}
/*
* (non-Javadoc)
*
* @see bjc.utils.data.IPair#merge(java.util.function.BiFunction)
*/
@Override
public <E> E merge(BiFunction<L, R, E> merger) {
if (merger == null) {
throw new NullPointerException("Merger must be non-null");
}
return merger.apply(leftValue, rightValue);
}
@Override
public String toString() {
String leftValueString;
if (leftValue != null) {
leftValueString = leftValue.toString();
} else {
leftValueString = "(null)";
}
String rightValueString;
if (rightValue != null) {
rightValueString = rightValue.toString();
} else {
rightValueString = "(null)";
}
return "pair[l=" + leftValueString + ", r=" + rightValueString
+ "]";
}
@Override
public <L2, R2> IPair<L2, R2> bind(
BiFunction<L, R, IPair<L2, R2>> binder) {
return binder.apply(leftValue, rightValue);
}
}
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