Add utils for new shuffle.

Utils/NSArray+ShuffleUtils.h

@@ -0,0 +1,34 @@
+//
+//  Pair.h
+//  Cog
+//
+//  Created by Eric Hanneken on 2/13/08.
+//  Copyright 2008 Vincent Spader. All rights reserved.
+//
+
+#import <Cocoa/Cocoa.h>
+
+@interface NSArray (ShuffleUtils)
+
++ (NSArray *) arrayWithRandomLongs:(NSUInteger) count;
+
+/*
+ * zip produces a new array by pairing successive objects
+ * from two input arrays until one is exhausted.  Only
+ * pointers are copied; the objects are not.
+ */
++ (NSArray *)zipArray:(NSArray*)x withArray:(NSArray *) y;
+
+/*
+ * Unzip produces a new pair of arrays by separating
+ * an input array of pairs.  Only pointers are copied;
+ * the objects are not.
+ */
++ (NSArray *) unzipArray:(NSArray*) pairs;
+
+- (NSComparisonResult) compareFirsts:(id) y;
+- (id)first;
+- (id)second;
+
+
+@end

Utils/NSArray+ShuffleUtils.m

@@ -0,0 +1,81 @@
+//
+//  Pair.m
+//  Cog
+//
+//  Created by Eric Hanneken on 2/13/08.
+//  Copyright 2008 Vincent Spader. All rights reserved.
+//
+
+#import "NSArray+ShuffleUtils.h"
+
+
+@implementation NSArray (ShuffleUtils)
+
+/*
+ * Generates an array of random long integers in the range
+ * 0 to (2**31) - 1.  The length of the array is determined
+ * by the count parameter.
+ */
++ (NSArray *) arrayWithRandomLongs:(NSUInteger) count
+{
+	NSMutableArray* randomLongs = [NSMutableArray arrayWithCapacity:count];
+	NSUInteger i;
+	for (i = 0; i < count; ++i)
+	{
+		[randomLongs addObject:[NSNumber numberWithLong:random()]];
+	}
+	
+	return randomLongs;
+}
+
++ (NSArray *)zipArray:(NSArray*)x withArray:(NSArray *) y
+{
+	NSUInteger xCount = [x count];
+	NSUInteger yCount = [y count];
+	NSUInteger minCount = (xCount < yCount) ? xCount : yCount;
+	NSMutableArray* pairs = [NSMutableArray arrayWithCapacity:minCount];
+	NSUInteger i;
+	for (i = 0; i < minCount; ++i)
+	{
+		NSArray* p = [NSArray arrayWithObjects:[x objectAtIndex:i], [y objectAtIndex:i], nil];
+		[pairs addObject:p];
+	}
+	
+	return pairs;
+}
+
++ (NSArray *) unzipArray:(NSArray*) pairs
+{
+	NSMutableArray* first = [NSMutableArray arrayWithCapacity:[pairs count]];
+	NSMutableArray* second = [NSMutableArray arrayWithCapacity:[pairs count]];
+
+	for (NSArray *pair in pairs)
+	{
+		[first addObject:[pair first]];
+		[second addObject:[pair second]];
+	}
+	
+	return [NSArray arrayWithObjects:first,second,nil];
+}
+
+
+/*
+ * Compares two pairs by their first objects.
+ */
+- (NSComparisonResult) compareFirsts:(id) y
+{
+	return [[self first] compare:[y first]];
+}
+
+- (id)first
+{
+	return [self objectAtIndex:0];
+}
+
+- (id)second
+{
+	return [self objectAtIndex:1];
+}
+
+
+@end