From a72783156744869a3fa03681608a8be0ea4231f4 Mon Sep 17 00:00:00 2001
From: Colin Eberhardt <colin.eberhardt@gmail.com>
Date: Tue, 24 Jun 2014 10:02:26 +0100
Subject: [PATCH] Added a sortBy method

---
 ExSwift/Array.swift                  | 13 +++++++++++++
 ExSwiftTests/ExSwiftArrayTests.swift | 10 ++++++++++
 README.md                            |  1 +
 3 files changed, 24 insertions(+)

diff --git a/ExSwift/Array.swift b/ExSwift/Array.swift
index 580edad..9c4dfe4 100644
--- a/ExSwift/Array.swift
+++ b/ExSwift/Array.swift
@@ -664,6 +664,19 @@ extension Array {
         return result
         
     }
+  
+    /**
+    *  Sorts the array by the given comparison function
+    *  @param isOrderedBefore
+    *  @return An array that is sorted by the given function
+    */
+    func sortBy (isOrderedBefore: (T, T) -> Bool) -> Array<T> {
+        var clone = self
+        clone.unshare()
+        clone.sort(isOrderedBefore)
+        return clone
+    }
+
 
     /**
     *  Removes the last element from self and returns it
diff --git a/ExSwiftTests/ExSwiftArrayTests.swift b/ExSwiftTests/ExSwiftArrayTests.swift
index cc93766..89ae8f3 100644
--- a/ExSwiftTests/ExSwiftArrayTests.swift
+++ b/ExSwiftTests/ExSwiftArrayTests.swift
@@ -17,6 +17,16 @@ class ExtensionsArrayTests: XCTestCase {
         array = [1, 2, 3, 4, 5]
     }
 
+    func testSortBy () {
+        var sourceArray = [2,3,6,5]
+        var sortedArray = sourceArray.sortBy {$0 < $1}
+        
+        // check that the source array as not been mutated
+        XCTAssertEqualObjects(sourceArray, [2, 3, 6, 5])
+        // check that the destination has been sorted
+        XCTAssertEqualObjects(sortedArray, [2, 3, 5, 6])
+    }
+  
     func testReject () {
         var odd = array.reject({
             return $0 % 2 == 0
diff --git a/README.md b/README.md
index 34917f1..feb1a46 100644
--- a/README.md
+++ b/README.md
@@ -83,6 +83,7 @@ Name | Signature
 **`reduceRight`**|`reduceRight <U>(initial: U, combine: (U, Element) -> U) -> U`
 **`implode`**|`implode <C: ExtensibleCollection> (separator: C) -> C?`
 **`flatten`**|`flatten <OutType> () -> OutType[]`
+**`sortBy`**|`sortBy (isOrderedBefore: (T, T) -> Bool) -> Array<T> `
 
 #### Class Methods ####