Merge branch 'master' of github.com:bculkin2442/bjc-utils2

1 files changed, 89 insertions, 24 deletions

diff --git a/base/src/main/java/bjc/utils/gen/WeightedRandom.java b/base/src/main/java/bjc/utils/gen/WeightedRandom.java
index 405d685..71de333 100644
--- a/base/src/main/java/bjc/utils/gen/WeightedRandom.java
+++ b/base/src/main/java/bjc/utils/gen/WeightedRandom.java
@@ -2,9 +2,7 @@ package bjc.utils.gen;
 
 import java.util.Random;
 
-import bjc.utils.data.IHolder;
 import bjc.utils.data.IPair;
-import bjc.utils.data.Identity;
 import bjc.utils.data.Pair;
 import bjc.utils.funcdata.FunctionalList;
 import bjc.utils.funcdata.IList;
@@ -16,7 +14,7 @@ import bjc.utils.funcdata.IList;
  * @author ben
  *
  * @param <E>
- *        The type of values that are randomly selected.
+ *                The type of values that are randomly selected.
  */
 public class WeightedRandom<E> {
 	private final IList<IPair<Integer, E>> values;
@@ -29,17 +27,18 @@ public class WeightedRandom<E> {
 	private final static Random BASE = new Random();
 
 	private boolean exhaust;
+
 	/**
 	 * Create a new weighted random generator with the specified source of
 	 * randomness.
 	 *
 	 * @param src
-	 *        The source of randomness to use.
+	 *                The source of randomness to use.
 	 */
 	public WeightedRandom(Random src) {
 		values = new FunctionalList<>();
 
-		if(src == null) throw new NullPointerException("Source of randomness must not be null");
+		if (src == null) throw new NullPointerException("Source of randomness must not be null");
 
 		source = src;
 	}
@@ -63,10 +62,10 @@ public class WeightedRandom<E> {
 	 * Add a probability for a specific result to be given.
 	 *
 	 * @param chance
-	 *        The chance to get this result.
+	 *                The chance to get this result.
 	 *
 	 * @param result
-	 *        The result to get when the chance comes up.
+	 *                The result to get when the chance comes up.
 	 */
 	public void addProbability(final int chance, final E result) {
 		values.add(new Pair<>(chance, result));
@@ -83,15 +82,20 @@ public class WeightedRandom<E> {
 		return generateValue(source);
 	}
 
+	/**
+	 * Generate a random value, using the specified Random.
+	 * 
+	 * @param rn
+	 *                The Random instance to use.
+	 * @return A random value.
+	 */
 	public E generateValue(Random rn) {
 		int target = rn.nextInt(totalChance);
-		int i = 0;
-
-		for(IPair<Integer, E> val : values) {
+		for (IPair<Integer, E> val : values) {
 			int prob = val.getLeft();
 
-			if(target < prob) {
-				if(exhaust) {
+			if (target < prob) {
+				if (exhaust) {
 					totalChance -= val.getLeft();
 					values.removeMatching(val);
 				}
@@ -100,11 +104,11 @@ public class WeightedRandom<E> {
 			}
 
 			target -= prob;
-			i      += 1;
 		}
 
 		return null;
 	}
+
 	/**
 	 * Return a list of values that can be generated by this generator
 	 *
@@ -124,17 +128,41 @@ public class WeightedRandom<E> {
 		return values;
 	}
 
+	/**
+	 * Get a descending value.
+	 * 
+	 * Descending values are quite simple. You have a 1 in factor chance to
+	 * advance to the next value, otherwise, the current value is the one
+	 * returned.
+	 * 
+	 * @param factor
+	 *                The descent factor to use.
+	 * @return A random value.
+	 */
 	public E getDescent(int factor) {
 		return getDescent(factor, source);
 	}
 
+	/**
+	 * Get a descending value.
+	 * 
+	 * Descending values are quite simple. You have a 1 in factor chance to
+	 * advance to the next value, otherwise, the current value is the one
+	 * returned.
+	 * 
+	 * @param factor
+	 *                The descent factor to use.
+	 * @param rn
+	 *                The Random instance to use.
+	 * @return A random value.
+	 */
 	public E getDescent(int factor, Random rn) {
-		if(values.getSize() == 0) return null;
+		if (values.getSize() == 0) return null;
 
-		for(IPair<Integer, E> val : values) {
-			if(rn.nextInt(factor) == 0) continue;
+		for (IPair<Integer, E> val : values) {
+			if (rn.nextInt(factor) == 0) continue;
 
-			if(exhaust) {
+			if (exhaust) {
 				totalChance -= val.getLeft();
 
 				values.removeMatching(val);
@@ -144,29 +172,61 @@ public class WeightedRandom<E> {
 		}
 
 		IPair<Integer, E> val = values.getByIndex(values.getSize() - 1);
-		if(exhaust) values.removeMatching(val);
+		if (exhaust) values.removeMatching(val);
 
 		return val.getRight();
 	}
 
+	/**
+	 * Get a value, treating this as a set of binomial trials.
+	 * 
+	 * Essentially, the system rolls a bound-sided dice trials times, and
+	 * marks a success for every roll less than or equal to target.
+	 * 
+	 * @param target
+	 *                The number to roll at or under.
+	 * @param bound
+	 *                The maximum roll value.
+	 * @param trials
+	 *                The number of times to roll.
+	 * @return The value at the index corresponding to the number of
+	 *         successes.
+	 */
 	public E getBinomial(int target, int bound, int trials) {
 		return getBinomial(target, bound, trials, source);
 	}
 
+	/**
+	 * Get a value, treating this as a set of binomial trials.
+	 * 
+	 * Essentially, the system rolls a bound-sided dice trials times, and
+	 * marks a success for every roll less than or equal to target.
+	 * 
+	 * @param target
+	 *                The number to roll at or under.
+	 * @param bound
+	 *                The maximum roll value.
+	 * @param trials
+	 *                The number of times to roll.
+	 * @param rn
+	 *                The Random instance to use.
+	 * @return The value at the index corresponding to the number of
+	 *         successes.
+	 */
 	public E getBinomial(int target, int bound, int trials, Random rn) {
-		if(values.getSize() == 0) return null;
+		if (values.getSize() == 0) return null;
 
 		int numSuc = 0;
 
-		for(int i = 0; i < trials; i++) {
-			/* 
+		for (int i = 0; i < trials; i++) {
+			/*
 			 * Adjust for zero, because it's easy to think of this
 			 * as rolling a bound-sided dice and marking a success
 			 * for every roll less than or equal to target.
 			 */
 			int num = rn.nextInt(bound) + 1;
 
-			if(num <= target) {
+			if (num <= target) {
 				//System.err.printf("\t\tTRACE: mark binomial success (%d <= 1d%d, %d)\n", target, bound, num);
 				numSuc += 1;
 			}
@@ -174,7 +234,7 @@ public class WeightedRandom<E> {
 
 		//System.err.printf("\tTRACE: got %d success for binomial trials (%d <= 1d%d, %d times)\n", numSuc, target, bound, trials);
 		IPair<Integer, E> val = values.getByIndex(Math.min(numSuc, values.getSize() - 1));
-		if(exhaust) {
+		if (exhaust) {
 			totalChance -= val.getLeft();
 
 			values.removeMatching(val);
@@ -183,9 +243,14 @@ public class WeightedRandom<E> {
 		return val.getRight();
 	}
 
+	/**
+	 * Return a new WeightedRandom that is exhaustible (only returns one value once).
+	 * 
+	 * @return A new WeightedRandom that is exhaustible.
+	 */
 	public WeightedRandom<E> exhaustible() {
 		IList<IPair<Integer, E>> lst = new FunctionalList<>();
-		for(IPair<Integer, E> val : values) {
+		for (IPair<Integer, E> val : values) {
 			lst.add(val);
 		}