util.fn
Class FnIterable<T>

java.lang.Object
  util.fn.FnIterable<T>

Type Parameters:

T - type of elements of the sequence

All Implemented Interfaces:

Iterable<T>

public class FnIterable<T>
extends Object
implements Iterable<T>

Functional programming like sequences. This class provides map-like functionality.

Method Summary

static <T> FnIterable<T>	from(Iterable<T> it) Creates a new functional sequence from an Iterable object
Iterator<T>	iterator()
<U> FnIterable<U>	map(Lambda<T,U> fn) Maps function to sequence
<U> U	reduce(Lambda2<U,T,U> fn, U initial) Reduces this sequence to a value.
List<T>	toList()
<U> FnIterable<Pair<T,U>>	zip(FnIterable<U> o) Produces a sequence of pairs from two sequences.

Methods inherited from class java.lang.Object

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

Method Detail

from

public static <T> FnIterable<T> from(Iterable<T> it)

Creates a new functional sequence from an Iterable object

Type Parameters:

T - type of elements of the sequence

Parameters:

it - the iterable object

Returns:

a functional sequence view of the iterable object

zip

public final <U> FnIterable<Pair<T,U>> zip(FnIterable<U> o)

Produces a sequence of pairs from two sequences.

  {a1, a2, a3, ...}.zip({b1, b2, b3, ...}) ==> {(a1, b1), (a2, b2), (a3, b3), ...}
 

Type Parameters:

U - type of elements of the argument sequence

Parameters:

o - argument sequence to zip with

Returns:

sequence of pairs combining this and argument sequence

map

public final <U> FnIterable<U> map(Lambda<T,U> fn)

Maps function to sequence

  {a1, a2, a3, ...}.map(fn) ==> {fn(a1), fn(a2), fn(a3), ...}
 

Type Parameters:

U - type of elements in result sequence

Parameters:

fn - function from elements in this sequence to elements of result sequence

Returns:

a sequence of the return values of the function

reduce

public final <U> U reduce(Lambda2<U,T,U> fn,
                          U initial)

Reduces this sequence to a value.

  {}.reduce(fn, initial)  ==> initial
  {a1, a2, a3, ...}.reduce(fn, initial) ==> fn(... fn(fn(fn(initial, a1), a2), a3) ...)
 

Type Parameters:

U - type of the resulting value

Parameters:

fn - function to reduce sequence

initial - initial value to pass reducing function

Returns:

resulting value from applying function over sequence

toList

public final List<T> toList()

Returns:

a copy of this sequence as a list

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>