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

Class FoldLeft<A,B>

java.lang.Object

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

Type Parameters:

A - The Iterable element type

B - The accumulation type

All Implemented Interfaces:

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

public final class FoldLeft<A,B>
extends java.lang.Object
implements Fn3<Fn2<? super B,? super A,? extends B>,B,java.lang.Iterable<A>,B>

Given an Iterable of As, a starting value B, and a Fn2<B, A, B>, iteratively accumulate over the Iterable, ultimately returning a final B value. If the Iterable is empty, just return the starting B value. Note that, as the name implies, this function accumulates from left to right, such that foldLeft(f, 0, asList(1, 2, 3, 4, 5)) is evaluated as f(f(f(f(f(0, 1), 2), 3), 4), 5).

For more information, read about Catamorphisms.

See Also:

FoldRight

Field Summary

Fields

Modifier and Type	Field	Description
private static FoldLeft<?,?>	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor	Description
private	FoldLeft()

Method Summary

Modifier and Type	Method	Description
B	checkedApply(Fn2<? super B,? super A,? extends B> fn, B acc, java.lang.Iterable<A> as)
static <A,B> FoldLeft<A,B>	foldLeft()
static <A,B> Fn2<B,java.lang.Iterable<A>,B>	foldLeft(Fn2<? super B,? super A,? extends B> fn)
static <A,B> Fn1<java.lang.Iterable<A>,B>	foldLeft(Fn2<? super B,? super A,? extends B> fn, B acc)
static <A,B> B	foldLeft(Fn2<? super B,? super A,? extends B> fn, B acc, java.lang.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.Fn1

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

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

checkedApply, toBiFunction

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

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

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

coerce

Field Detail

INSTANCE

private static final FoldLeft<?,?> INSTANCE

Constructor Detail

FoldLeft

private FoldLeft()

Method Detail

checkedApply

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

Specified by:

checkedApply in interface Fn3<Fn2<? super B,? super A,? extends B>,B,java.lang.Iterable<A>,B>

foldLeft

public static <A,B> FoldLeft<A,B> foldLeft()

foldLeft

public static <A,B> Fn2<B,java.lang.Iterable<A>,B> foldLeft(Fn2<? super B,? super A,? extends B> fn)

foldLeft

public static <A,B> Fn1<java.lang.Iterable<A>,B> foldLeft(Fn2<? super B,? super A,? extends B> fn,
                                                                      B acc)

foldLeft

public static <A,B> B foldLeft(Fn2<? super B,? super A,? extends B> fn,
                                     B acc,
                                     java.lang.Iterable<A> as)