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package bjc.utils.data;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
import bjc.utils.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(
IPair<OtherLeft, OtherRight> otherPair) {
return combine(otherPair,
(left, otherLeft) -> new Pair<>(left, otherLeft),
(right, otherRight) -> new Pair<>(right, otherRight));
}
/**
* 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);
/**
* Immediately perfom the specified action with the contents of this
* pair
*
* @param consumer
* The action to perform on the pair
*/
public default void doWith(BiConsumer<LeftType, RightType> consumer) {
merge((leftValue, rightValue) -> {
consumer.accept(leftValue, rightValue);
return null;
});
}
@Override
default <OldLeft, OldRight,
NewLeft> Function<Bifunctor<OldLeft, OldRight>,
Bifunctor<NewLeft, OldRight>> fmapLeft(
Function<OldLeft, NewLeft> func) {
return (argumentPair) -> {
if (!(argumentPair instanceof IPair<?, ?>)) {
throw new IllegalArgumentException(
"This function can only be applied to instances of IPair");
}
IPair<OldLeft, OldRight> argPair = (IPair<OldLeft,
OldRight>) argumentPair;
return argPair.mapLeft(func);
};
}
@Override
default <OldLeft, OldRight, NewRight> Function<
Bifunctor<OldLeft, OldRight>, Bifunctor<OldLeft, NewRight>>
fmapRight(Function<OldRight, NewRight> func) {
return (argumentPair) -> {
if (!(argumentPair instanceof IPair<?, ?>)) {
throw new IllegalArgumentException(
"This function can only be applied to instances of IPair");
}
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);
}
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