From 8dfddc586f49b2d7ce4a4d712334a28584c0b315 Mon Sep 17 00:00:00 2001
From: "Benjamin J. Culkin" <bjculkin@mix.wvu.edu>
Date: Sun, 3 Jun 2018 20:57:27 -0300
Subject: Efficency updates

Change a few things to use more efficent implementations
---
 base/src/main/java/bjc/utils/data/Pair.java        |  8 +++++
 .../main/java/bjc/utils/gen/WeightedRandom.java    | 36 ++++++++++------------
 2 files changed, 25 insertions(+), 19 deletions(-)

(limited to 'base')

diff --git a/base/src/main/java/bjc/utils/data/Pair.java b/base/src/main/java/bjc/utils/data/Pair.java
index 40e4849..df7e199 100644
--- a/base/src/main/java/bjc/utils/data/Pair.java
+++ b/base/src/main/java/bjc/utils/data/Pair.java
@@ -102,6 +102,14 @@ public class Pair<LeftType, RightType> implements IPair<LeftType, RightType> {
 		return String.format("Pair [leftValue='%s', rightValue='%s']", leftValue, rightValue);
 	}
 
+	public LeftType getLeft() {
+		return leftValue;
+	}
+
+	public RightType getRight() {
+		return rightValue;
+	}
+
 	@Override
 	public int hashCode() {
 		final int prime = 31;
diff --git a/base/src/main/java/bjc/utils/gen/WeightedRandom.java b/base/src/main/java/bjc/utils/gen/WeightedRandom.java
index be8b8c2..c7cee19 100644
--- a/base/src/main/java/bjc/utils/gen/WeightedRandom.java
+++ b/base/src/main/java/bjc/utils/gen/WeightedRandom.java
@@ -24,7 +24,7 @@ public class WeightedRandom<E> {
 	private final IList<E> results;
 
 	/* The source for any needed random numbers */
-	private final Random source;
+	private Random source;
 	/* The total chance for all values. */
 	private int totalChance;
 
@@ -37,7 +37,7 @@ public class WeightedRandom<E> {
 	 */
 	public WeightedRandom(final Random src) {
 		probabilities = new FunctionalList<>();
-		results = new FunctionalList<>();
+		results       = new FunctionalList<>();
 
 		if(src == null) throw new NullPointerException("Source of randomness must not be null");
 
@@ -66,25 +66,23 @@ public class WeightedRandom<E> {
 	 * @return A random value selected in a weighted fashion.
 	 */
 	public E generateValue() {
-		final IHolder<Integer> value = new Identity<>(source.nextInt(totalChance));
-		final IHolder<E> current = new Identity<>();
-		final IHolder<Boolean> picked = new Identity<>(true);
-
-		probabilities.forEachIndexed((index, probability) -> {
-			if(picked.unwrap(bool -> bool)) {
-				if(value.unwrap((number) -> number < probability)) {
-					current.transform((result) -> results.getByIndex(index));
-
-					picked.transform((bool) -> false);
-				} else {
-					value.transform((number) -> number - probability);
-				}
-			}
-		});
-
-		return current.unwrap((result) -> result);
+		return generateValue(source);
 	}
 
+	public E generateValue(Random rn) {
+		int target = rn.nextInt(totalChance);
+
+		int i = 0;
+
+		for(int prob : probabilities) {
+			if(target <= prob) return results.getByIndex(i);
+
+			target -= prob;
+			i      += 1;
+		}
+
+		throw new NullPointerException("Fell off the end of the results list");
+	}
 	/**
 	 * Return a list of values that can be generated by this generator
 	 *
-- 
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