CPCharacterSet archiving support when the set is of the characterSetWithCharactersInString kind.

Foundation/CPCharacterSet.j

@@ -344,6 +344,27 @@ var _builtInCharacterSets = {};
 
 @end
 
+var _CPStringContentCharacterSetStringKey = @"_CPStringContentCharacterSetStringKey";
+
+@implementation _CPStringContentCharacterSet (CPCoding)
+
+- (id)initWithCoder:(CPCoder)aCoder
+{
+    if (self)
+    {
+        _string = [aCoder decodeObjectForKey:_CPStringContentCharacterSetStringKey]
+    }
+
+    return self;
+}
+
+- (void)encodeWithCoder:(CPCoder)aCoder
+{
+    [aCoder encodeObject:_string forKey:_CPStringContentCharacterSetStringKey];
+}
+
+@end
+
 _CPCharacterSetTrimAtBeginning  = 1 << 1;
 _CPCharacterSetTrimAtEnd        = 1 << 2;
 

Tests/Foundation/CPCharacterSetTest.j

@@ -0,0 +1,17 @@
+@import <Foundation/CPCharacterSet.j>
+
+@implementation CPCharacterSetTest : OJTestCase
+
+- (void)testArchiving
+{
+    var charSet = [CPCharacterSet characterSetWithCharactersInString:"abc"],
+        archived = [CPKeyedArchiver archivedDataWithRootObject:charSet],
+        unarchived = [CPKeyedUnarchiver unarchiveObjectWithData:archived];
+
+    [self assertTrue:[unarchived characterIsMember:'a']];
+    [self assertTrue:[unarchived characterIsMember:'b']];
+    [self assertTrue:[unarchived characterIsMember:'c']];
+    [self assertFalse:[unarchived characterIsMember:'d']];
+}
+
+@end