added IsDigit to string

git-svn-id: svn://10.0.0.236/trunk@1423 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/string/obsolete/nsString.cpp

@@ -1084,6 +1084,18 @@ PRBool nsString::IsSpace(PRUnichar ch) {
   return PR_FALSE;
 }
 
+/**-------------------------------------------------------
+ *  
+ *  
+ *  @update  gess 3/31/98
+ *  @param   
+ *  @return  isalpha
+ *------------------------------------------------------*/
+PRBool nsString::IsDigit(PRUnichar ch) {
+  // XXX i18n
+  return PRBool((ch >= '0') && (ch <= '9'));
+}
+
 /**-------------------------------------------------------
  *  This method trims characters found in aTrimSet from
  *  either end of the underlying string.