0
@@ -284,7 +284,7 @@ extern char *nu_parsedFilename(int i);
0
         while (cursor && (cursor != Nu__null)) {
0
             [args setCar:[cursor car]];
0
             id result = [block evalWithArguments:args context:Nu__null];
0
-            if (result && (result != Nu__null)) {
0
+            if (nu_valueIsTrue(result)) {
0
                 [resultCursor setCdr:[NuCell cellWithCar:[cursor car] cdr:[resultCursor cdr]]];
0
                 resultCursor = [resultCursor cdr];
0
             }
0
@@ -307,7 +307,7 @@ extern char *nu_parsedFilename(int i);
0
         while (cursor && (cursor != Nu__null)) {
0
             [args setCar:[cursor car]];
0
             id result = [block evalWithArguments:args context:Nu__null];
0
-            if (result && (result != Nu__null)) {
0
+            if (nu_valueIsTrue(result)) {
0
                 [args release];
0
                 return [cursor car];
0
             }
0
@@ -341,6 +341,25 @@ extern char *nu_parsedFilename(int i);
0
     return result;
0
 }
0
 
0
+- (id) mapSelector:(SEL) sel
0
+{
0
+    NuCell *parent = [[NuCell alloc] init];
0
+    id args = [[NuCell alloc] init];
0
+    id cursor = self;
0
+    id resultCursor = parent;
0
+    while (cursor && (cursor != Nu__null)) {
0
+        id object = [cursor car];
0
+        id result = [object performSelector:sel];
0
+        [resultCursor setCdr:[NuCell cellWithCar:result cdr:[resultCursor cdr]]];
0
+        cursor = [cursor cdr];
0
+        resultCursor = [resultCursor cdr];
0
+    }
0
+    [args release];
0
+    NuCell *result = [parent cdr];
0
+    [parent release];
0
+    return result;
0
+}
0
+
0
 - (id) reduce:(NuBlock *) block from:(id) initial
0
 {
0
     id result = initial;

0
@@ -61,6 +61,16 @@ limitations under the License.
0
     return self;
0
 }
0
 
0
+static bool nu_valueIsTrue(id value)
0
+{
0
+    bool result = value && (value != Nu__null);
0
+    if (result && nu_objectIsKindOfClass(value, [NSNumber class])) {
0
+        if ([value doubleValue] == 0.0)
0
+            result = false;
0
+    }
0
+    return result;
0
+}
0
+
0
 - (NSArray *) select:(NuBlock *) block
0
 {
0
     NSMutableArray *selected = [[NSMutableArray alloc] init];
0
@@ -71,7 +81,7 @@ limitations under the License.
0
         while ((object = [enumerator nextObject])) {
0
             [args setCar:object];
0
             id result = [block evalWithArguments:args context:Nu__null];
0
-            if (result && (result != Nu__null)) {
0
+            if (nu_valueIsTrue(result)) {
0
                 [selected addObject:object];
0
             }
0
         }
0
@@ -89,7 +99,7 @@ limitations under the License.
0
         while ((object = [enumerator nextObject])) {
0
             [args setCar:object];
0
             id result = [block evalWithArguments:args context:Nu__null];
0
-            if (result && (result != Nu__null)) {
0
+            if (nu_valueIsTrue(result)) {
0
                 [args release];
0
                 return object;
0
             }

0
@@ -31,6 +31,16 @@ limitations under the License.
0
 
0
 id Nu__null = 0;
0
 
0
+bool nu_valueIsTrue(id value)
0
+{
0
+    bool result = value && (value != Nu__null);
0
+    if (result && nu_objectIsKindOfClass(value, [NSNumber class])) {
0
+        if ([value doubleValue] == 0.0)
0
+            result = false;
0
+    }
0
+    return result;
0
+}
0
+
0
 @interface NuApplication : NSObject
0
 {
0
     NSMutableArray *arguments;

0
@@ -33,3 +33,6 @@ limitations under the License.
0
 
0
 @interface NuContinueException : NSException {}
0
 @end
0
+
0
+// use this to test a value for "truth"
0
+bool nu_valueIsTrue(id value);

0
@@ -51,16 +51,6 @@ limitations under the License.
0
 
0
 @end
0
 
0
-static bool valueIsTrue(id value)
0
-{
0
-    bool result = value && (value != Nu__null);
0
-    if (result && nu_objectIsKindOfClass(value, [NSNumber class])) {
0
-        if ([value doubleValue] == 0.0)
0
-            result = false;
0
-    }
0
-    return result;
0
-}
0
-
0
 @implementation NuOperator : NSObject
0
 - (id) callWithArguments:(id)cdr context:(NSMutableDictionary *)context {return nil;}
0
 - (id) evalWithArguments:(id)cdr context:(NSMutableDictionary *)context {return [self callWithArguments:cdr context:context];}
0
@@ -220,7 +210,7 @@ static bool valueIsTrue(id value)
0
     while (pairs != Nu__null) {
0
         id condition = [[pairs car] car];
0
         id test = [condition evalWithContext:context];
0
-        if (valueIsTrue(test)) {
0
+        if (nu_valueIsTrue(test)) {
0
             value = test;
0
             id cursor = [[pairs car] cdr];
0
             while (cursor && (cursor != Nu__null)) {
0
@@ -290,7 +280,7 @@ static bool valueIsTrue(id value)
0
     id result = Nu__null;
0
     id test = [[cdr car] evalWithContext:context];
0
 
0
-    bool testIsTrue = flip ^ valueIsTrue(test);
0
+    bool testIsTrue = flip ^ nu_valueIsTrue(test);
0
     bool noneIsTrue = !testIsTrue;
0
 
0
     id expressions = [cdr cdr];
0
@@ -299,7 +289,7 @@ static bool valueIsTrue(id value)
0
         if (nu_objectIsKindOfClass(nextExpression, [NuCell class])) {
0
             /*if ([nextExpression car] == elseifSymbol) {
0
                 test = [[[[expressions car] cdr] car] evalWithContext:context];
0
-                testIsTrue = noneIsTrue && valueIsTrue(test);
0
+                testIsTrue = noneIsTrue && nu_valueIsTrue(test);
0
                 noneIsTrue = noneIsTrue && !testIsTrue;
0
                 if (testIsTrue)
0
                     // skip the test:
0
@@ -318,7 +308,7 @@ static bool valueIsTrue(id value)
0
         else {
0
             /*if (nextExpression == elseifSymbol) {
0
                 test = [[[expressions cdr] car] evalWithContext:context];
0
-                testIsTrue = noneIsTrue && valueIsTrue(test);
0
+                testIsTrue = noneIsTrue && nu_valueIsTrue(test);
0
                 noneIsTrue = noneIsTrue && !testIsTrue;
0
                 expressions = [expressions cdr];            // skip the test
0
             }
0
@@ -358,7 +348,7 @@ static bool valueIsTrue(id value)
0
 {
0
     id result = Nu__null;
0
     id test = [[cdr car] evalWithContext:context];
0
-    while (valueIsTrue(test)) {
0
+    while (nu_valueIsTrue(test)) {
0
         @try
0
         {
0
             id expressions = [cdr cdr];
0
@@ -391,7 +381,7 @@ static bool valueIsTrue(id value)
0
 {
0
     id result = Nu__null;
0
     id test = [[cdr car] evalWithContext:context];
0
-    while (!valueIsTrue(test)) {
0
+    while (!nu_valueIsTrue(test)) {
0
         @try
0
         {
0
             id expressions = [cdr cdr];
0
@@ -431,7 +421,7 @@ static bool valueIsTrue(id value)
0
     [loopinit evalWithContext:context];
0
     // evaluate the loop condition
0
     id test = [looptest evalWithContext:context];
0
-    while (valueIsTrue(test)) {
0
+    while (nu_valueIsTrue(test)) {
0
         @try
0
         {
0
             id expressions = [cdr cdr];
0
@@ -1071,7 +1061,7 @@ static bool valueIsTrue(id value)
0
     id value = Nu__null;
0
     while (cursor && (cursor != Nu__null)) {
0
         value = [[cursor car] evalWithContext:context];
0
-        if (!valueIsTrue(value))
0
+        if (!nu_valueIsTrue(value))
0
             return Nu__null;
0
         cursor = [cursor cdr];
0
     }
0
@@ -1089,7 +1079,7 @@ static bool valueIsTrue(id value)
0
     id cursor = cdr;
0
     while (cursor && (cursor != Nu__null)) {
0
         id value = [[cursor car] evalWithContext:context];
0
-        if (valueIsTrue(value))
0
+        if (nu_valueIsTrue(value))
0
             return value;
0
         cursor = [cursor cdr];
0
     }
0
@@ -1108,7 +1098,7 @@ static bool valueIsTrue(id value)
0
     id cursor = cdr;
0
     if (cursor && (cursor != Nu__null)) {
0
         id value = [[cursor car] evalWithContext:context];
0
-        return valueIsTrue(value) ? Nu__null : [symbolTable symbolWithCString:"t"];
0
+        return nu_valueIsTrue(value) ? Nu__null : [symbolTable symbolWithCString:"t"];
0
     }
0
     return Nu__null;
0
 }