cyclops.box

Class LazyImmutable<T>

java.lang.Object

cyclops.box.LazyImmutable<T>

Type Parameters:

T -

All Implemented Interfaces:

ConvertableToReactiveSeq<T>, ToStream<T>, To<LazyImmutable<T>>, Transformable<T>, Zippable<T>, java.lang.Iterable<T>, java.util.function.Consumer<T>, java.util.function.Supplier<T>

public class LazyImmutable<T>
extends java.lang.Object
implements To<LazyImmutable<T>>, java.util.function.Supplier<T>, java.util.function.Consumer<T>, Transformable<T>, Zippable<T>

A class that represents an 'immutable' value that is generated inside a lambda expression, but is accessible outside it It will only allow it's value to be set once. Unfortunately the compiler won't be able to tell if setOnce is called more than once example usage

 
 public static <T> Supplier<T> memoiseSupplier(Supplier<T> s){
		LazyImmutable<T> lazy = LazyImmutable.def();
		return () -> lazy.computeIfAbsent(s);
	}
 

Has map and flatMap methods, but is not a Monad (see example usage above for why, it is the initial mutation that is valuable).

Constructor Summary

Constructors

Constructor and Description
LazyImmutable()

Method Summary

Modifier and Type	Method and Description
void	accept(T t)
<U> LazyImmutable<U>	cast(java.lang.Class<? extends U> type) Cast all elements in a stream to a given type, possibly throwing a ClassCastException.
T	computeIfAbsent(java.util.function.Supplier<T> lazy) Get the current value or set if it has not been set yet
static <T> LazyImmutable<T>	def()
boolean	equals(java.lang.Object obj)
<R> LazyImmutable<? extends R>	flatMap(java.util.function.Function<? super T,? extends LazyImmutable<? extends R>> fn) FlatMap the value stored in Immutable Closed Value from one Value to another If this is an unitiatilised ImmutableClosedValue, an uninitialised closed value will be returned instead
T	get()
int	hashCode()
boolean	isSet()
java.util.Iterator<T>	iterator()
<R> LazyImmutable<R>	map(java.util.function.Function<? super T,? extends R> fn) Map the value stored in this Immutable Closed Value from one Value to another If this is an unitiatilised ImmutableClosedValue, an uninitialised closed value will be returned instead
static <T> LazyImmutable<T>	of(T value)
LazyImmutable<T>	peek(java.util.function.Consumer<? super T> c) Peek at the current value of this Transformable, without transforming it
LazyImmutable<T>	setOnce(T val) Set the value of this ImmutableClosedValue If it has already been set will throw an exception
ReactiveSeq<T>	stream()
<R> LazyImmutable<R>	trampoline(java.util.function.Function<? super T,? extends Trampoline<? extends R>> mapper) Performs a map operation that can call a recursive method without running out of stack space
static <T> LazyImmutable<T>	unbound() Create an intermediate unbound (or unitialised) ImmutableClosedValue)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.aol.cyclops2.types.To

to

Methods inherited from interface java.util.function.Consumer

andThen

Methods inherited from interface com.aol.cyclops2.types.Zippable

zip, zip, zip, zip3, zip3, zip4, zip4, zipP, zipP, zipS, zipS, zipWith, zipWithP, zipWithS

Methods inherited from interface com.aol.cyclops2.types.Transformable

retry, retry

Methods inherited from interface com.aol.cyclops2.types.stream.ToStream

futureStream, getStreamable, isEmpty, jdkStream, reactiveSeq, reveresedJDKStream, reveresedStream

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

LazyImmutable

public LazyImmutable()

Method Detail

get

public T get()

Specified by:

get in interface java.util.function.Supplier<T>

Returns:

Current value

unbound

public static <T> LazyImmutable<T> unbound()

Create an intermediate unbound (or unitialised) ImmutableClosedValue)

Returns:

unitialised ImmutableClosedValue

of

public static <T> LazyImmutable<T> of(T value)

Parameters:

value - Create an initialised ImmutableClosedValue with specified value

Returns:

Initialised ImmutableClosedValue

def

public static <T> LazyImmutable<T> def()

Returns:

a defined, but unitialised LazyImmutable

map

public <R> LazyImmutable<R> map(java.util.function.Function<? super T,? extends R> fn)

Map the value stored in this Immutable Closed Value from one Value to another If this is an unitiatilised ImmutableClosedValue, an uninitialised closed value will be returned instead

Specified by:

map in interface Transformable<T>

Parameters:

fn - Mapper function

Returns:

new ImmutableClosedValue with new mapped value

flatMap

public <R> LazyImmutable<? extends R> flatMap(java.util.function.Function<? super T,? extends LazyImmutable<? extends R>> fn)

FlatMap the value stored in Immutable Closed Value from one Value to another If this is an unitiatilised ImmutableClosedValue, an uninitialised closed value will be returned instead

Parameters:

fn - Flat Mapper function

Returns:

new ImmutableClosedValue with new mapped value

setOnce

public LazyImmutable<T> setOnce(T val)

Set the value of this ImmutableClosedValue If it has already been set will throw an exception

Parameters:

val - Value to set to

Returns:

Current set Value

computeIfAbsent

public T computeIfAbsent(java.util.function.Supplier<T> lazy)

Get the current value or set if it has not been set yet

Parameters:

lazy - Supplier to generate new value

Returns:

Current value

isSet

public boolean isSet()

Returns:

true if this LazyImmutable value has been set

accept

public void accept(T t)

Specified by:

accept in interface java.util.function.Consumer<T>

stream

public ReactiveSeq<T> stream()

Specified by:

stream in interface ToStream<T>

Returns:

ReactiveSeq from this Streamable

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T>

cast

public <U> LazyImmutable<U> cast(java.lang.Class<? extends U> type)

Description copied from interface: Transformable

Cast all elements in a stream to a given type, possibly throwing a ClassCastException. // ClassCastException ReactiveSeq.of(1, "a", 2, "b", 3).cast(Integer.class)

Specified by:

cast in interface Transformable<T>

peek

public LazyImmutable<T> peek(java.util.function.Consumer<? super T> c)

Description copied from interface: Transformable

Peek at the current value of this Transformable, without transforming it

  
  
  
    of(1,2,3).map(System.out::println)
    
    1
    2
    3
  
 
 

Specified by:

peek in interface Transformable<T>

Parameters:

c - Consumer that recieves each element from this Transformable

Returns:

Transformable that will peek at each value

trampoline

public <R> LazyImmutable<R> trampoline(java.util.function.Function<? super T,? extends Trampoline<? extends R>> mapper)

Description copied from interface: Transformable

Performs a map operation that can call a recursive method without running out of stack space

 
 ReactiveSeq.of(10,20,30,40)
    			 .trampoline(i-> fibonacci(i))
    			 .forEach(System.out::println); 
    			 
    	Trampoline<Long> fibonacci(int i){
    		return fibonacci(i,1,0);
    	}
    	Trampoline<Long> fibonacci(int n, long a, long b) {
        	return n == 0 ? Trampoline.done(b) : Trampoline.more( ()->fibonacci(n-1, a+b, a));
    	}		 
    			 
 55
    	6765
    	832040
    	102334155
 
 
 ReactiveSeq.of(10_000,200_000,3_000_000,40_000_000)
    			 .trampoline(i-> fibonacci(i))
    			 .forEach(System.out::println);
    			 
    			 
 completes successfully
 
 

Specified by:

trampoline in interface Transformable<T>

Parameters:

mapper - TCO Transformation function

Returns:

Transformable transformed by the supplied transformation function

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object