Initial/untested implementation of new string function.

Source/NSString.m

@@ -1886,6 +1886,59 @@ GSICUCollatorOpen(NSStringCompareOptions mask, NSLocale *locale)
     }
 }
 
+- (NSString *) stringByAddingPercentWithAllowedCharacters: (NSCharacterSet *)aSet
+{
+  NSData	*data = [self dataUsingEncoding: NSUTF8StringEncoding];
+  NSString	*s = nil;
+
+  if (data != nil)
+    {
+      unsigned char	*src = (unsigned char*)[data bytes];
+      unsigned int	slen = [data length];
+      unsigned char	*dst;
+      unsigned int	spos = 0;
+      unsigned int	dpos = 0;
+
+      dst = (unsigned char*)NSZoneMalloc(NSDefaultMallocZone(), slen * 3);
+      while (spos < slen)
+	{
+	  unsigned char	c = src[spos++];
+	  unsigned int	hi;
+	  unsigned int	lo;
+
+	  if([aSet characterIsMember: c])
+	    {
+
+	      if (c <= 32 || c > 126 || c == 34 || c == 35 || c == 37
+		  || c == 60 || c == 62 || c == 91 || c == 92 || c == 93
+		  || c == 94 || c == 96 || c == 123 || c == 124 || c == 125)
+		{
+		  dst[dpos++] = '%';
+		  hi = (c & 0xf0) >> 4;
+		  dst[dpos++] = (hi > 9) ? 'A' + hi - 10 : '0' + hi;
+		  lo = (c & 0x0f);
+		  dst[dpos++] = (lo > 9) ? 'A' + lo - 10 : '0' + lo;
+		}
+	      else
+		{
+		  dst[dpos++] = c;
+		}
+	    }
+	  s = [[NSString alloc] initWithBytes: dst
+				       length: dpos
+				     encoding: NSASCIIStringEncoding];
+	  NSZoneFree(NSDefaultMallocZone(), dst);
+	  IF_NO_GC([s autorelease];)
+	}
+    }
+  return s;
+}
+
+- (NSString *) stringByRemovingEscapeEncoding
+{
+  return nil;
+}
+
 /**
  * Constructs a new ASCII string which is a representation of the receiver
  * in which characters are escaped where necessary in order to produce a
@@ -1949,16 +2002,6 @@ GSICUCollatorOpen(NSStringCompareOptions mask, NSLocale *locale)
   return s;
 }
 
-- (NSString *) stringByAddingPercentWithAllowedCharacters: (NSCharacterSet *)aSet
-{
-  return nil;
-}
-
-- (NSString *) stringByRemovingEscapeEncoding
-{
-  return nil;
-}
-
 /**
  * Constructs a new string consisting of this instance followed by the string
  * specified by format.