tiny optimisation to allow intermeidate substrings to be released earlier

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@35939 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,12 @@
+2013-01-08  Richard Frith-Macdonald <rfm@gnu.org>
+
+        * Source/GSString.m:
+        When creating a substring (A) of a substring (B) or a string (C),
+        we now retain the (C) in (A) rather than having (C) retain (B)
+        which in turn retains (A).  This has the advantage that it is
+        possible for the intermediate (B) to be released if nothing else
+        ues it.
+        
 2013-01-05 00:49-EST Gregory John Casamento <greg.casamento@gmail.com>
 
 	* Headers/Foundation/NSMetadata.h: Add _ to delegate.

Source/GSString.m

@@ -3846,6 +3846,33 @@ agree, create a new GSCInlineString otherwise.
   DESTROY(_parent);
   [super dealloc];
 }
+
+- (NSString*) substringFromRange: (NSRange)aRange
+{
+  id    s;
+
+  GS_RANGE_CHECK(aRange, _count);
+  s = createTinyString((char*)_contents.c + aRange.location, aRange.length);
+  if (nil == s)
+    {
+      s = substring_c((GSStr)_parent, aRange);
+    }
+  return s;
+}
+
+- (NSString*) substringWithRange: (NSRange)aRange
+{
+  id    s;
+
+  GS_RANGE_CHECK(aRange, _count);
+  s = createTinyString((char*)_contents.c + aRange.location, aRange.length);
+  if (nil == s)
+    {
+      s = substring_c((GSStr)_parent, aRange);
+    }
+  return s;
+}
+
 @end
 
 
@@ -4220,6 +4247,21 @@ agree, create a new GSUInlineString otherwise.
   DESTROY(_parent);
   [super dealloc];
 }
+
+- (NSString*) substringFromRange: (NSRange)aRange
+{
+  GS_RANGE_CHECK(aRange, _count);
+  aRange.location += (_contents.u - _parent->_contents.u);
+  return substring_u((GSStr)_parent, aRange);
+}
+
+- (NSString*) substringWithRange: (NSRange)aRange
+{
+  GS_RANGE_CHECK(aRange, _count);
+  aRange.location += (_contents.u - _parent->_contents.u);
+  return substring_u((GSStr)_parent, aRange);
+}
+
 @end