From afd6847ef3cf9aee357e6c23fc2f665413fa01d1 Mon Sep 17 00:00:00 2001
From: Max Howell <mxcl@me.com>
Date: Fri, 7 Mar 2014 18:17:17 -0600
Subject: [PATCH] NSArray.chunk()

---
 NSArray+YOLO.m  | 10 ++++++++++
 README.markdown |  9 +++++++++
 YOLO.h          |  1 +
 tests           |  6 ++++++
 4 files changed, 26 insertions(+)

diff --git a/NSArray+YOLO.m b/NSArray+YOLO.m
index 4161bf9..00bb2d3 100644
--- a/NSArray+YOLO.m
+++ b/NSArray+YOLO.m
@@ -7,6 +7,16 @@ - (NSSet *)set {
     return [NSSet setWithArray:self];
 }
 
+- (NSArray *(^)(NSUInteger))chunk {
+    return ^(NSUInteger size){
+        id aa = [NSMutableArray new];
+        const int n = self.count / size;
+        for (int x = 0; x < n; ++x)
+            [aa addObject:self.slice(x*size, size)];
+        return aa;
+    };
+}
+
 - (NSArray *(^)(id (^)(id o)))pmap {
     return ^NSArray *(id (^block)(id))
     {
diff --git a/README.markdown b/README.markdown
index 3a9d1aa..ab9ff38 100644
--- a/README.markdown
+++ b/README.markdown
@@ -461,6 +461,15 @@ code.
 
 `has` was chosen over `contains` or `includes` because it is short and clear.
 
+###NSArray.chunk()
+```objc
+id rv = @[@1, @2, @3, @4].chunk(2)
+
+// rv => @[@[@1, @2], @[@3, @4]]
+```
+
+Chunks your array into an array of chunk-size arrays.
+
 ###NSArray.partition()
 ```objc
 id rv = @[@"A", @"B", @"AA"].partition(^(NSString *s){
diff --git a/YOLO.h b/YOLO.h
index 2af2ae6..04c15eb 100644
--- a/YOLO.h
+++ b/YOLO.h
@@ -47,6 +47,7 @@
 @end
 
 @interface NSArray (YOLO)
+- (NSArray *(^)(NSUInteger))chunk;
 - (BOOL)empty;
 - (BOOL (^)(id o))has;
 - (NSArray *(^)(id (^)(id o)))pmap;
diff --git a/tests b/tests
index 10fd409..3422b74 100755
--- a/tests
+++ b/tests
@@ -491,6 +491,12 @@ int main() {
     STAssertEqualObjects(aa, bb, @"");
 }
 
+- (void)testChunk {
+    id aa = @[@1, @2, @3, @4].chunk(2);
+    id bb = @[@[@1, @2], @[@3, @4]];
+    STAssertEqualObjects(aa, bb, @"");
+}
+
 - (void)testPartition {
     id aa = @[@1, @2, @3, @4].partition(^(NSNumber *n){
         return n.intValue % 2 == 0;