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@@ -123,9 +123,18 @@ extern id Nu__null;
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     // evaluate the body of the block with the saved context (implicit progn)
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     id value = Nu__null;
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     id cursor = body;
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-    while (cursor && (cursor != Nu__null)) {
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-        value = [[cursor car] evalWithContext:evaluation_context];
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-        cursor = [cursor cdr];
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+    @try
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+    {
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+        while (cursor && (cursor != Nu__null)) {
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+            value = [[cursor car] evalWithContext:evaluation_context];
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+            cursor = [cursor cdr];
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+        }
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+    }
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+    @catch (NuReturnException *exception) {
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+        value = [exception value];
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+    }
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+    @catch (id exception) {
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+        @throw(exception);
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     }
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     //    NSLog(@"before releasing, evaluation context %@ retain count %d", evaluation_context, [evaluation_context retainCount]);
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     //    NSLog(@"before releasing, value %@ retain count %d", value, [value retainCount]);
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@@ -176,9 +185,18 @@ extern id Nu__null;
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     // evaluate the body of the block with the saved context (implicit progn)
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     id value = Nu__null;
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     id cursor = body;
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-    while (cursor && (cursor != Nu__null)) {
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-        value = [[cursor car] evalWithContext:evaluation_context];
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-        cursor = [cursor cdr];
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+    @try
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+    {
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+        while (cursor && (cursor != Nu__null)) {
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+            value = [[cursor car] evalWithContext:evaluation_context];
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+            cursor = [cursor cdr];
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+        }
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+    }
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+    @catch (NuReturnException *exception) {
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+        value = [exception value];
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+    }
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+    @catch (id exception) {
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+        @throw(exception);
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     }
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     [value retain];
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     [value autorelease];

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@@ -34,5 +34,12 @@ limitations under the License.
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 @interface NuContinueException : NSException {}
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 @end
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+@interface NuReturnException : NSException
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+{
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+    id value;
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+}
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+
0
+@end
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+
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 // use this to test a value for "truth"
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 bool nu_valueIsTrue(id value);

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@@ -51,6 +51,27 @@ limitations under the License.
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 @end
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+@implementation NuReturnException
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+- (id) initWithValue:(id) v;
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+{
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+    [super initWithName:@"NuReturnException" reason:@"A return operator was evaluated" userInfo:nil];
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+    value = [v retain];
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+    return self; ;
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+}
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+
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+- (void) dealloc
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+{
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+    [value release];
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+    [super dealloc];
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+}
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+
0
+- (id) value
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+{
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+    return value;
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+}
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+
0
+@end
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+
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 @implementation NuOperator : NSObject
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 - (id) callWithArguments:(id)cdr context:(NSMutableDictionary *)context {return nil;}
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 - (id) evalWithArguments:(id)cdr context:(NSMutableDictionary *)context {return [self callWithArguments:cdr context:context];}
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@@ -1603,7 +1624,7 @@ id loadNuLibraryFile(NSString *nuFileName, id parser, id context, id symbolTable
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 - (id) callWithArguments:(id)cdr context:(NSMutableDictionary *)context
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 {
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-    @throw [[NuBreakException alloc] init];
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+    @throw [[[NuBreakException alloc] init] autorelease];
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     return nil;                                   // unreached
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 }
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@@ -1616,7 +1637,24 @@ id loadNuLibraryFile(NSString *nuFileName, id parser, id context, id symbolTable
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 - (id) callWithArguments:(id)cdr context:(NSMutableDictionary *)context
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 {
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-    @throw [[NuContinueException alloc] init];
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+    @throw [[[NuContinueException alloc] init] autorelease];
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+    return nil;                                   // unreached
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+}
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+
0
+@end
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+
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+@interface Nu_return_operator : NuOperator {}
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+@end
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+
0
+@implementation Nu_return_operator
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+
0
+- (id) callWithArguments:(id)cdr context:(NSMutableDictionary *)context
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+{
0
+    id value = nil;
0
+    if (cdr && cdr != Nu__null) {
0
+        value = [[cdr car] evalWithContext:context];
0
+    }
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+    @throw [[[NuReturnException alloc] initWithValue:value] autorelease];
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     return nil;                                   // unreached
0
 }
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0
@@ -1772,6 +1810,7 @@ void load_builtins(NuSymbolTable *symbolTable)
0
     install("for",      Nu_for_operator);
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     install("break",    Nu_break_operator);
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     install("continue", Nu_continue_operator);
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+    install("return",   Nu_return_operator);
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0
     install("try",      Nu_try_operator);
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     #ifdef DARWIN