fj.data.fingertrees

Class Digit<V,A>

java.lang.Object

fj.data.fingertrees.Digit<V,A>

Direct Known Subclasses:

Four, One, Three, Two

public abstract class Digit<V,A>
extends java.lang.Object

A digit is a vector of 1-4 elements. Serves as a pointer to the prefix or suffix of a finger tree.

Method Summary

Methods

Modifier and Type	Method and Description
abstract <B> B	foldLeft(F<B,F<A,B>> f, B z) Folds this digit to the left using the given function and the given initial value.
abstract <B> B	foldRight(F<A,F<B,B>> f, B z) Folds this digit to the right using the given function and the given initial value.
<B> Digit<V,B>	map(F<A,B> f, Measured<V,B> m) Maps a function across the elements of this digit, measuring with the given measurement.
abstract <B> B	match(F<One<V,A>,B> one, F<Two<V,A>,B> two, F<Three<V,A>,B> three, F<Four<V,A>,B> four) Structural pattern matching on digits.
V	measure() Returns the sum of the measurements of this digit according to the monoid.
A	reduceLeft(F<A,F<A,A>> f) Folds this digit to the right using the given function.
A	reduceRight(F<A,F<A,A>> f) Folds this digit to the right using the given function.
FingerTree<V,A>	toTree() Returns the tree representation of this digit.

Methods inherited from class java.lang.Object

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

Method Detail

foldRight

public abstract <B> B foldRight(F<A,F<B,B>> f,
              B z)

Folds this digit to the right using the given function and the given initial value.

Parameters:

f - A function with which to fold this digit.

z - An initial value to apply at the rightmost end of the fold.

Returns:

The right reduction of this digit with the given function and the given initial value.

foldLeft

public abstract <B> B foldLeft(F<B,F<A,B>> f,
             B z)

Folds this digit to the left using the given function and the given initial value.

Parameters:

f - A function with which to fold this digit.

z - An initial value to apply at the leftmost end of the fold.

Returns:

The left reduction of this digit with the given function and the given initial value.

reduceRight

public final A reduceRight(F<A,F<A,A>> f)

Folds this digit to the right using the given function.

Parameters:

f - A function with which to fold this digit.

Returns:

The right reduction of this digit with the given function.

reduceLeft

public final A reduceLeft(F<A,F<A,A>> f)

Folds this digit to the right using the given function.

Parameters:

f - A function with which to fold this digit.

Returns:

The right reduction of this digit with the given function.

map

public final <B> Digit<V,B> map(F<A,B> f,
                 Measured<V,B> m)

Maps a function across the elements of this digit, measuring with the given measurement.

Parameters:

f - A function to map across the elements of this digit.

m - A measuring for the function's domain (destination type).

Returns:

A new digit with the same structure as this digit, but with all elements transformed with the given function and measured with the given measuring.

match

public abstract <B> B match(F<One<V,A>,B> one,
          F<Two<V,A>,B> two,
          F<Three<V,A>,B> three,
          F<Four<V,A>,B> four)

Structural pattern matching on digits. Applies the function that matches the structure of this digit.

Parameters:

one - A function to apply to this digit if it's One.

two - A function to apply to this digit if it's Two.

three - A function to apply to this digit if it's Three.

four - A function to apply to this digit if it's Four.

Returns:

The result of applying the function matching this Digit.

measure

public final V measure()

Returns the sum of the measurements of this digit according to the monoid.

Returns:

the sum of the measurements of this digit according to the monoid.

toTree

public final FingerTree<V,A> toTree()

Returns the tree representation of this digit.

Returns:

the tree representation of this digit.