From 5de49b1d4d690c70beefe22823fc54872e67f22f Mon Sep 17 00:00:00 2001
From: Daniel Tartaglia <dtartaglia@hanekedesign.com>
Date: Sun, 24 May 2015 20:36:28 -0400
Subject: [PATCH] Add 'aggregate' function and spelling corrections.

---
 OSXPlayground.playground/Contents.swift | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/OSXPlayground.playground/Contents.swift b/OSXPlayground.playground/Contents.swift
index e2afda94..a3dc32e2 100644
--- a/OSXPlayground.playground/Contents.swift
+++ b/OSXPlayground.playground/Contents.swift
@@ -135,7 +135,7 @@ var onlyEvensSubscriber = multipleObservable
 This filter tracks the last value emitted and removes like values. This function is good for reducing noise in a sequence.
 */
 
-let debugSubscriber = returnElements(1, 2, 3, 1, 1, 4)
+let distinctUntilChangedSubscriber = returnElements(1, 2, 3, 1, 1, 4)
     >- distinctUntilChanged
     >- subscribeNext { value in
         println("\(value)")
@@ -143,8 +143,22 @@ let debugSubscriber = returnElements(1, 2, 3, 1, 1, 4)
 
 /*:
 In the example above, the values 1, 2, 3, 1, 4 will be printed. The extra 1 will be filtered out.
+There are several different versions of `distinctUntilChanged`. Have a look in the file Observable+Single.swift to review them.
 */
 
+/*:
+## Aggregating a sequence
+
+### `aggregate`
+This function will perform a function on each element in the sequence until it is completed, then send a message with the aggregate value. It works much like the Swift `reduce` function works on sequences.
+*/
+
+let aggregateSubscriber = multipleObservable
+    >- aggregate(0, +)
+    >- subscribeNext { value in
+        println("\(value)")
+}
+
 /*:
 To be continued...
 */