Class WeightedPool<T>

A weighted collection from which items of type T can be chosen at random. Although the item is picked at random, weights will be considered. Items with higher weights will be more likely to be picked than items with lower weights.

Inheritance

System.Object

WeightedPool<T>

Implements

IWeightedPool<T>

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: RogueSharp.Random

Assembly: RogueSharp.dll

Syntax

public class WeightedPool<T> : IWeightedPool<T>

Type Parameters

Name	Description
T	The type of item to be stored in the WeightedPool

Examples

A treasure lookup table in a board game could be implemented as a WeightedPool. A booster pack for a collectable card game could be implemented as a WeightedPool.

Constructors

WeightedPool()

Construct a new weighted pool using the default random number generator provided with .NET This constructor does not take a clone function so Choose() cannot be called, only Draw()

Declaration

public WeightedPool()

WeightedPool(IRandom, Func<T, T>)

Construct a new weighted pool using the provided random number generator and clone function

Declaration

public WeightedPool(IRandom random, Func<T, T> cloneFunc = null)

Parameters

Type	Name	Description
IRandom	random	A class implementing IRandom that will be used to generate pseudo-random numbers necessary to pick items from the WeightedPool
System.Func<T, T>	cloneFunc	A function that takes an object of type T and returns a clone of the item. When comparing the original object and the clone, all properties should be equal. The clone will have a different reference than the original object.

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when provided "random" argument is null

Properties

Count

How many items are in the WeightedPool

Declaration

public int Count { get; }

Property Value

Type	Description
System.Int32

Methods

Add(T, Int32)

Add an item of type T to the WeightedPool with the given weight

Declaration

public void Add(T item, int weight)

Parameters

Type	Name	Description
T	item	The item to add to the WeightedPool
System.Int32	weight	The chance that the item will be picked at random from the pool when weighted against all other items. Higher weights mean it is more likely to be picked.

Exceptions

Type	Condition
System.ArgumentNullException	Thrown when provided "item" argument is null
System.ArgumentException	Thrown when provided "weight" argument is not greater than 0
System.OverflowException	Thrown when adding the weight of the new item to the pool exceeds Int32.MaxValue

Choose()

Choose an item at random from the pool, keeping weights into consideration. The item itself will remain in the pool and a clone of the item selected will be returned.

Declaration

public T Choose()

Returns

Type	Description
T	A clone of the item of type T from the WeightedPool

Exceptions

Type	Condition
System.InvalidOperationException	Thrown when a clone function was not defined when the pool was constructed
System.InvalidOperationException	Thrown when the pool is empty
System.InvalidOperationException	Thrown when the random lookup is greater than the total weight. Could only happen if a bad implementation of IRandom were provided

Clear()

Remove all items from the WeightedPool. The WeightedPool will be empty after calling this method.

Declaration

public void Clear()

Draw()

Take an item at random from the pool, keeping weights into consideration. The item will be removed from the pool.

Declaration

public T Draw()

Returns

Type	Description
T	An item of type T from the WeightedPool

Exceptions

Type	Condition
System.InvalidOperationException	Thrown when the pool is empty
System.InvalidOperationException	Thrown when the random lookup is greater than the total weight. Could only happen if a bad implementation of IRandom were provided

Implements

IWeightedPool<T>