net.automatalib.commons.util.random

Class WeightedSupplier<T>

java.lang.Object

net.automatalib.commons.util.random.WeightedSupplier<T>

Type Parameters:

T - the supplied type

All Implemented Interfaces:

Function<Random,T>, Supplier<T>

public class WeightedSupplier<T>
extends Object
implements Supplier<T>, Function<Random,T>

This class implements a Supplier that randomly delegates to one of several (sub-)suppliers. Each sub-supplier is assigned a weight, which determines the probability of it being chosen upon calls to get().

The add(Object, int) and add(Supplier, int) methods return a reference to this, so calls can be chained.

Usage example:

 
 Supplier<String> mySupplier = ...;
 String str = new WeightedSupplier<String>()
  .add("foo", 5)
  .add(mySupplier, 10)
  .get();
 
 

With a one-third chance, the value "foo" will be assigned to str. Otherwise (i.e., with a two-thirds chance), the result of mySupplier.get() will be assigned to str. Note that in the former case, mySupplier.get() will not even be invoked.

Author:

Malte Isberner

Constructor Summary

Constructors

Constructor and Description
WeightedSupplier()

Method Summary

Modifier and Type	Method and Description
WeightedSupplier<T>	add(Supplier<? extends T> supplier, int weight) Adds a sub-supplier with a given weight.
WeightedSupplier<T>	add(T obj, int weight) Adds an object to be supplied with a given weight.
T	apply(Random r)
Supplier<T>	forRandom(Random r)
T	get()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Constructor Detail

WeightedSupplier

public WeightedSupplier()

Method Detail

add

public WeightedSupplier<T> add(T obj,
                               int weight)

Adds an object to be supplied with a given weight.

Parameters:

obj - the object to be supplied

weight - the weight

Returns:

this

add

public WeightedSupplier<T> add(Supplier<? extends T> supplier,
                               int weight)

Adds a sub-supplier with a given weight.

Parameters:

supplier - the sub-supplier

weight - the weight

Returns:

this

apply

public T apply(Random r)

Specified by:

apply in interface Function<Random,T>

get

public T get()

Specified by:

get in interface Supplier<T>

forRandom

public Supplier<T> forRandom(Random r)