diff options
Diffstat (limited to 'BJC-Utils2/src/main/java/bjc/utils/funcdata/theory')
| -rw-r--r-- | BJC-Utils2/src/main/java/bjc/utils/funcdata/theory/Bifunctor.java | 88 |
1 files changed, 41 insertions, 47 deletions
diff --git a/BJC-Utils2/src/main/java/bjc/utils/funcdata/theory/Bifunctor.java b/BJC-Utils2/src/main/java/bjc/utils/funcdata/theory/Bifunctor.java index e8c74fc..d3ebdac 100644 --- a/BJC-Utils2/src/main/java/bjc/utils/funcdata/theory/Bifunctor.java +++ b/BJC-Utils2/src/main/java/bjc/utils/funcdata/theory/Bifunctor.java @@ -14,6 +14,43 @@ import java.util.function.Function; */ public interface Bifunctor<LeftType, RightType> { /** + * Lift a pair of functions to a single function that maps over both + * parts of a pair + * + * @param <OldLeft> + * The old left type of the pair + * @param <OldRight> + * The old right type of the pair + * @param <NewLeft> + * The new left type of the pair + * @param <NewRight> + * The new right type of the pair + * @param leftFunc + * The function that maps over the left of the pair + * @param rightFunc + * The function that maps over the right of the pair + * @return A function that maps over both parts of the pair + */ + public default <OldLeft, OldRight, NewLeft, NewRight> Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, NewRight>> bimap( + Function<OldLeft, NewLeft> leftFunc, + Function<OldRight, NewRight> rightFunc) { + Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, NewRight>> bimappedFunc = ( + argPair) -> { + Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, OldRight>> leftMapper = argPair + .<OldLeft, OldRight, NewLeft> fmapLeft(leftFunc); + + Bifunctor<NewLeft, OldRight> leftMappedFunctor = leftMapper + .apply(argPair); + Function<Bifunctor<NewLeft, OldRight>, Bifunctor<NewLeft, NewRight>> rightMapper = leftMappedFunctor + .<NewLeft, OldRight, NewRight> fmapRight(rightFunc); + + return rightMapper.apply(leftMappedFunctor); + }; + + return bimappedFunc; + } + + /** * Lift a function to operate over the left part of this pair * * @param <OldLeft> @@ -27,9 +64,8 @@ public interface Bifunctor<LeftType, RightType> { * pair * @return The function lifted to work over the left side of bifunctors */ - public <OldLeft, OldRight, NewLeft> - Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, OldRight>> - fmapLeft(Function<OldLeft, NewLeft> func); + public <OldLeft, OldRight, NewLeft> Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, OldRight>> fmapLeft( + Function<OldLeft, NewLeft> func); /** * Lift a function to operate over the right part of this pair @@ -46,50 +82,8 @@ public interface Bifunctor<LeftType, RightType> { * @return The function lifted to work over the right side of * bifunctors */ - public <OldLeft, OldRight, NewRight> - Function<Bifunctor<OldLeft, OldRight>, Bifunctor<OldLeft, NewRight>> - fmapRight(Function<OldRight, NewRight> func); - - /** - * Lift a pair of functions to a single function that maps over both - * parts of a pair - * - * @param <OldLeft> - * The old left type of the pair - * @param <OldRight> - * The old right type of the pair - * @param <NewLeft> - * The new left type of the pair - * @param <NewRight> - * The new right type of the pair - * @param leftFunc - * The function that maps over the left of the pair - * @param rightFunc - * The function that maps over the right of the pair - * @return A function that maps over both parts of the pair - */ - public default <OldLeft, OldRight, NewLeft, NewRight> - Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, NewRight>> - bimap(Function<OldLeft, NewLeft> leftFunc, - Function<OldRight, NewRight> rightFunc) { - Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, NewRight>> bimappedFunc = - (argPair) -> { - Function<Bifunctor<OldLeft, OldRight>, Bifunctor<NewLeft, OldRight>> leftMapper = - argPair.<OldLeft, OldRight, NewLeft> fmapLeft( - leftFunc); - - Bifunctor<NewLeft, OldRight> leftMappedFunctor = - leftMapper.apply(argPair); - Function<Bifunctor<NewLeft, OldRight>, Bifunctor<NewLeft, NewRight>> rightMapper = - leftMappedFunctor - .<NewLeft, OldRight, NewRight> fmapRight( - rightFunc); - - return rightMapper.apply(leftMappedFunctor); - }; - - return bimappedFunc; - } + public <OldLeft, OldRight, NewRight> Function<Bifunctor<OldLeft, OldRight>, Bifunctor<OldLeft, NewRight>> fmapRight( + Function<OldRight, NewRight> func); /** * Get the value contained on the left of this bifunctor |