Merge pull request #1736 from cacaodev/_CPJavaScriptArray-objectsAtIndexes

_CPJavaScriptArray -objectsAtIndexes: implementation.

Foundation/CPArray/_CPJavaScriptArray.j

@@ -120,6 +120,29 @@ var concat = Array.prototype.concat,
     return self[anIndex];
 }
 
+- (CPArray)objectsAtIndexes:(CPIndexSet)indexes
+{
+    if ([indexes lastIndex] >= self.length)
+        [CPException raise:CPRangeException reason:_cmd + " indexes out of bounds"];
+
+    var ranges = indexes._ranges,
+        count  = ranges.length,
+        result = [],
+             i = 0;
+
+    for (; i < count; i++)
+    {
+        var range = ranges[i],
+            loc = range.location,
+            len = range.length,
+            subArray = self.slice(loc, loc + len);
+
+        result.splice.apply(result, [result.length, 0].concat(subArray));
+    }
+
+    return result;
+}
+
 - (CPUInteger)indexOfObject:(id)anObject inRange:(CPRange)aRange
 {
     // Only use isEqual: if our object is a CPObject.

Tests/Foundation/CPArrayPerformanceTest.j

@@ -212,6 +212,52 @@ var ELEMENTS = 100,
     }
 }
 
+- (void)testObjectsAtIndexesSpeed
+{
+    var SIZE = 1000,
+        c = SIZE,
+        r = rr = REPEATS = 100,
+        location = 0,
+        array = [CPArray array],
+        indexes = [CPIndexSet indexSet];
+
+    while (c--)
+        array.push(""+c);
+
+    while (location < SIZE - 10)
+    {
+        var rangeLength = ROUND(10 * RAND());
+        [indexes addIndexesInRange:CPMakeRange(location, rangeLength)];
+
+        location += rangeLength + ROUND(10 * RAND());
+    }
+
+    var d = new Date();
+    while (r--)
+        var test1 = [array _previous_objectsAtIndexes:indexes];
+    var dd = new Date();
+
+    while (rr--)
+        var test2 = [array objectsAtIndexes:indexes];
+    var ddd = new Date();
+
+    CPLog.warn("\n_CPJavaScriptArray -objectsAtIndexes:");
+    CPLog.warn("           CPArray -objectsAtIndexes: " + (dd - d) + "ms.");
+    CPLog.warn("_CPJavaScriptArray -objectsAtIndexes: " + (ddd - dd) + "ms.");
+
+    if (![test1 isEqual:test2])
+        [self fail:"_CPJavaScriptArray -objectsAtIndexes: returns an wrong value"];
+}
+
+@end
+
+@implementation _CPJavaScriptArray (ObjectsAtIndexes)
+
+- (CPArray)_previous_objectsAtIndexes:(CPIndexSet)indexes
+{
+    return [super objectsAtIndexes:indexes];
+}
+
 @end
 
 @implementation CPArray (NativeSort)