3 files changed, 12 insertions, 2 deletions
diff --git a/GNUmakefile b/GNUmakefile
index 22398e9..13a7c6c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -27,8 +27,8 @@ BUNDLE_NAME = Test
 
 ADDITIONAL_OBJCFLAGS = -Wall
 
-ToiletKit_OBJC_FILES = MLKCharacter.m MLKCons.m MLKBackquoteReader.m	\
-                       MLKBinding.m MLKCommaReader.m MLKDoubleFloat.m	\
+ToiletKit_OBJC_FILES = MLKBackquoteReader.m MLKBinding.m MLKCharacter.m	\
+                       MLKCommaReader.m MLKCons.m MLKDoubleFloat.m	\
                        MLKDynamicContext.m MLKEnvironment.m MLKFloat.m	\
                        MLKInteger.m MLKInterpretedClosure.m		\
                        MLKInterpreter.m MLKLinkedList.m			\
diff --git a/MLKCons.h b/MLKCons.h
index 739fb40..55f47c1 100644
--- a/MLKCons.h
+++ b/MLKCons.h
@@ -44,5 +44,7 @@
                                       // only
 -(NSString *)descriptionForLisp;
 
+-(id) copyWithZone:(NSZone *)zone;
+  
 -(void) dealloc;
 @end
diff --git a/MLKCons.m b/MLKCons.m
index 8b3084b..c557dc2 100644
--- a/MLKCons.m
+++ b/MLKCons.m
@@ -128,6 +128,14 @@
     return [NSString stringWithFormat:@"(%@)", [self bareDescriptionForLisp]];
 }
 
+-(id) copyWithZone:(NSZone *)zone
+{
+  MLKCons *copy = [MLKCons allocWithZone:zone];
+  ASSIGN (copy->_car, _car);
+  ASSIGN (copy->_cdr, _cdr);
+  return copy;
+}
+
 -(void) dealloc
 {
   RELEASE (_car);