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package bjc.utils.funcutils;
import java.util.Random;
import java.util.function.Consumer;
import bjc.funcdata.FunctionalList;
import bjc.funcdata.ListEx;
/**
* Utility methods on enums.
*
* @author ben
*/
public class EnumUtils {
/**
* Do an action for a random number of enum values.
*
* @param <E>
* The type of the enum.
*
* @param clasz
* The enum class.
*
* @param nValues
* The number of values to execute the action on.
*
* @param action
* The action to perform on random values.
*
* @param rnd
* The source of randomness to use.
*/
public static <E extends Enum<E>> void doForValues(final Class<E> clasz,
final int nValues, final Consumer<E> action, final Random rnd) {
final E[] enumValues = clasz.getEnumConstants();
final ListEx<E> valueList = new FunctionalList<>(enumValues);
final int randomValueCount = enumValues.length - nValues;
for (int i = 0; i <= randomValueCount; i++) {
final E rDir = valueList.randItem(rnd::nextInt);
valueList.removeMatching(rDir);
}
valueList.forEach(action);
}
/**
* Get a random value from an enum.
*
* @param <E>
* The type of the enum.
*
* @param clasz
* The class of the enum.
*
* @param rnd
* The random source to use.
*
* @return A random value from the specified enum.
*/
public static <E extends Enum<E>> E getRandomValue(final Class<E> clasz,
final Random rnd) {
final E[] enumValues = clasz.getEnumConstants();
return new FunctionalList<>(enumValues).randItem(rnd::nextInt);
}
}
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