From a3b91bdf42713b2e04341f271bd17abb0032f382 Mon Sep 17 00:00:00 2001
From: rfm <rfm@72102866-910b-0410-8b05-ffd578937521>
Date: Wed, 28 Jan 2009 12:03:41 +0000
Subject: [PATCH] Add fast enumeration

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@27711 72102866-910b-0410-8b05-ffd578937521
---
 ChangeLog                         |  6 ++++++
 Headers/Foundation/NSEnumerator.h | 16 +++++++++++++++-
 Source/NSEnumerator.m             | 19 +++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index fdabf1ca9..5761ddde2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2009-01-28  David Chisnall <csdavec@swansea.ac.uk>
+
+	* Headers/Foundation/NSEnumerator.h:
+	* Source/NSEnumerator.m:
+	Add Apple's fast enumeration protocol.
+
 2009-01-28  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/NSException.m: Fix problem preventing stack traccces from
diff --git a/Headers/Foundation/NSEnumerator.h b/Headers/Foundation/NSEnumerator.h
index 2ba652dd4..5fd2ce4fd 100644
--- a/Headers/Foundation/NSEnumerator.h
+++ b/Headers/Foundation/NSEnumerator.h
@@ -34,7 +34,21 @@
 extern "C" {
 #endif
 
-@interface NSEnumerator : NSObject
+typedef struct 
+{
+  unsigned long	state;
+  id		*itemsPtr;
+  unsigned long	*mutationsPtr;
+  unsigned long	extra[5];
+} NSFastEnumerationState;
+
+@protocol NSFastEnumeration
+- (NSUInteger) countByEnumeratingWithState: (NSFastEnumerationState *)state 
+				   objects: (id *)stackbuf
+				     count: (NSUInteger)len;
+@end
+
+@interface NSEnumerator : NSObject <NSFastEnumeration>
 - (NSArray *) allObjects;
 - (id) nextObject;
 @end
diff --git a/Source/NSEnumerator.m b/Source/NSEnumerator.m
index 7446ca1c7..ad71c5184 100644
--- a/Source/NSEnumerator.m
+++ b/Source/NSEnumerator.m
@@ -74,4 +74,23 @@
   return nil;
 }
 
+- (NSUInteger) countByEnumeratingWithState: (NSFastEnumerationState*)state 	
+				   objects: (id*)stackbuf
+				     count: (NSUInteger)len
+{
+  IMP nextObject = [self methodForSelector: @selector(nextObject)];
+  int i;
+
+  for (i = 0; i < len; i++)
+    {
+      id next = nextObject(self, @selector(nextObject));
+
+      if (nil == next)
+	{
+	  return i;
+	}
+      *(stackbuf+i) = next;
+    }
+  return len;
+}
 @end