com.jnape.palatable.lambda.functions.builtin.fn3

Class FoldRight<A,B>

java.lang.Object

com.jnape.palatable.lambda.functions.builtin.fn3.FoldRight<A,B>

Type Parameters:

A - The Iterable element type

B - The accumulation type

All Implemented Interfaces:

Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>>, Fn2<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>, Fn3<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Lazy<B>,Iterable<A>,Lazy<B>>, Applicative<Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>, Cartesian<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<?,?>>, Cocartesian<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<?,?>>, Contravariant<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Profunctor<?,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<?,?>>>, Functor<Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>, Profunctor<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<?,?>>, Monad<Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>, MonadReader<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>, MonadRec<Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>, MonadWriter<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Fn1<Lazy<B>,Fn1<Iterable<A>,Lazy<B>>>,Fn1<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,?>>

public final class FoldRight<A,B>
extends Object
implements Fn3<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Lazy<B>,Iterable<A>,Lazy<B>>

Given an Iterable of As, a starting lazy value B, and a Fn2<A, Lazy<B>, Lazy<B>>, iteratively accumulate over the Iterable, ultimately returning a final Lazy<B> value. If the Iterable is empty, just return the starting Lazy<B> value. This function is computationally the iterative inverse of FoldLeft, but uses Lazy to allow support stack-safe execution.

Example:

 
 Lazy<Iterable<Integer>> lazyCopy = foldRight(
     (head, lazyTail) -&gt; lazy(cons(head, () -&gt; lazyTail.value().iterator())),
     lazy(emptyList()),
     iterate(x -&gt; x + 1, 0));
 Iterable<Integer> copy = () -&gt; lazyCopy.value().iterator();
 take(3, copy).forEach(System.out::println); // prints "1, 2, 3"
 take(3, copy).forEach(System.out::println); // prints "1, 2, 3"
 
 

For more information, read about Catamorphisms.

See Also:

FoldLeft

Method Summary

Modifier and Type	Method and Description
Lazy<B>	checkedApply(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn, Lazy<B> acc, Iterable<A> as)
static <A,B> FoldRight<A,B>	foldRight()
static <A,B> Fn2<Lazy<B>,Iterable<A>,Lazy<B>>	foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn)
static <A,B> Fn1<Iterable<A>,Lazy<B>>	foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn, Lazy<B> acc)
static <A,B> Lazy<B>	foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn, Lazy<B> acc, Iterable<A> as)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn3

apply, apply, apply, checkedApply, compose, contraMap, diMapL, discardR, flip, fn3, fn3, fn3, uncurry, widen

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn2

checkedApply, curried, curry, fn2, fromBiFunction, toBiFunction

Methods inherited from interface com.jnape.palatable.lambda.functions.Fn1

andThen, carry, cartesian, censor, choose, cocartesian, diMap, diMapR, discardL, flatMap, fmap, fn1, fromFunction, lazyZip, listens, local, pure, pureFn1, thunk, toFunction, trampolineM, zip, zip

Methods inherited from interface com.jnape.palatable.lambda.monad.Monad

join

Methods inherited from interface com.jnape.palatable.lambda.functor.Functor

coerce

Method Detail

checkedApply

public Lazy<B> checkedApply(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn,
                            Lazy<B> acc,
                            Iterable<A> as)

Specified by:

checkedApply in interface Fn3<Fn2<? super A,? super Lazy<B>,? extends Lazy<B>>,Lazy<B>,Iterable<A>,Lazy<B>>

foldRight

public static <A,B> FoldRight<A,B> foldRight()

foldRight

public static <A,B> Fn2<Lazy<B>,Iterable<A>,Lazy<B>> foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn)

foldRight

public static <A,B> Fn1<Iterable<A>,Lazy<B>> foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn,
                                                       Lazy<B> acc)

foldRight

public static <A,B> Lazy<B> foldRight(Fn2<? super A,? super Lazy<B>,? extends Lazy<B>> fn,
                                      Lazy<B> acc,
                                      Iterable<A> as)