From f2ccdab2cefea6c4ba904d7671afce11654e2d95 Mon Sep 17 00:00:00 2001
From: Andrew McCallum <mccallum@gnu.org>
Date: Tue, 12 Mar 1996 20:39:58 +0000
Subject: [PATCH] Several minor fixes to return types and return values.
 ([ReverseEnumerator -nextObject]): Pass pointer to enum_state.
 ([ConstantIndexedCollection -prevObjectWithEnumState:]): Method overhauled.
 ([ConstantIndexedCollection -nextObjectWithEnumState:]): Likewise.
 ([ConstantIndexedCollection -newEnumState]): New method.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@1129 72102866-910b-0410-8b05-ffd578937521
---
 Source/IndexedCollection.m | 63 +++++++++++++++++++++++++++++---------
 1 file changed, 48 insertions(+), 15 deletions(-)

diff --git a/Source/IndexedCollection.m b/Source/IndexedCollection.m
index 9ab067335..087fe7ef9 100644
--- a/Source/IndexedCollection.m
+++ b/Source/IndexedCollection.m
@@ -26,12 +26,13 @@
 #include <stdio.h>
 #include <objects/Array.h>
 #include <objects/NSString.h>
+#include <objects/behavior.h>
 
 @implementation ReverseEnumerator
 
 - nextObject
 {
-  return [collection prevObjectWithEnumState: enum_state];
+  return [collection prevObjectWithEnumState: &enum_state];
 }
 
 @end
@@ -45,6 +46,7 @@
 - objectAtIndex: (unsigned)index
 {
   [self subclassResponsibility: _cmd];
+  return nil;
 }
 
 - firstObject
@@ -263,12 +265,24 @@
 
 - prevObjectWithEnumState: (void**)enumState
 {
-  /* *(unsigned*)enumState-1 is the index of the element 
-     that will be returned */
-  if (!(*enumState))
-    *(unsigned*)enumState = [self count]-1;
+  /* *(int*)enumState is the index of the element that was returned
+     last time -prevObjectWithEnumState: or -nextObjectWithEnumState
+     was called.  In -newEnumState, *(int*)enumState is initialized to
+     -2; The implementation of -newEnumState can be found below. */
+
+  /* If there are not objects in this collection, or we are being
+     asked for the object before the first object, return nil. */
+  if ([self isEmpty] || (*(int*)enumState) == 0)
+    return NO_OBJECT;
+
+  if (*(int*)enumState == -2)
+    /* enumState was just initialized by -newEnumState, start
+       at the end of the sequence. */
+    *(int*)enumState = [self count]-1;
   else
-    (*(unsigned*)enumState)--;
+    /* ...otherwise go to the previous index.*/
+    (*(int*)enumState)--;
+
   return [self objectAtIndex:(*(unsigned*)enumState)];
 }
 
@@ -279,31 +293,50 @@
 - shallowCopyRange: (IndexRange)aRange
 {
   [self notImplemented: _cmd];
+  return nil;
 }
 
 - shallowCopyInReverse
 {
   [self notImplemented: _cmd];
+  return nil;
 }
 
 - shallowCopyInReverseRange: (IndexRange)aRange
 {
   [self notImplemented: _cmd];
+  return nil;
 }
 
 
 // OVERRIDE SOME COLLECTION METHODS;
 
+- (void*) newEnumState
+{
+  return (void*) -2;
+}
+
 - nextObjectWithEnumState: (void**)enumState
 {
-  id ret;
-  /* *(unsigned*)enumState is the index of the element that will be returned */
-  if ([self isEmpty]
-      || (*(unsigned*)enumState) > [self count]-1)
+  /* *(int*)enumState is the index of the element that was returned
+     last time -prevObjectWithEnumState: or -nextObjectWithEnumState
+     was called.  In -newEnumState, *(int*)enumState is initialized to
+     -2. */
+
+  /* If there are not objects in this collection, or we are being
+     asked for the object after the last object, return nil. */
+  if ([self isEmpty] || (*(int*)enumState) > [self count]-1)
     return NO_OBJECT;
-  ret = [self objectAtIndex:(*(unsigned*)enumState)];
-  *(unsigned*)enumState = *(unsigned*)enumState + 1;
-  return ret;
+
+  if (*(int*)enumState == -2)
+    /* enumState was just initialized by -newEnumState, start
+       at the beginning of the sequence. */
+    *(int*)enumState = 0;
+  else
+    /* ...otherwise go the next index. */
+    (*(int*)enumState)++;
+
+  return [self objectAtIndex:(*(unsigned*)enumState)];
 }
 
 /* is this what we want? */
@@ -334,7 +367,7 @@
 
 // REPLACING;
 
-- replaceObjectAtIndex: (unsigned)index withObject: newObject
+- (void) replaceObjectAtIndex: (unsigned)index withObject: newObject
 {
   [self subclassResponsibility: _cmd];
 }
@@ -359,7 +392,7 @@
 
 - (void) removeRange: (IndexRange)aRange
 {
-  int count;
+  int count = aRange.length;
 
   CHECK_INDEX_RANGE_ERROR(aRange.location, [self count]);
   CHECK_INDEX_RANGE_ERROR(aRange.location+aRange.length-1, [self count]);