From: E.Allaert
                                                       Date: 05 November 1999 


             VLT-SW-OCT99 - RELEASE NOTES FOR TCL/TK
             =======================================

   The Tcl/Tk included with the VLT Common Software October 1999
   release contains the following core plus extensions:
        - Tcl 8.0.5
        - Tk 8.0.5
        - [incr Tcl] 3.0.1
        - [incr Tk] 3.0.1
        - iwidgets 3.0.1
        - tclX 8.0.4
        - TkX 8.0.4
        - BLT 2.4i
        - msqltcl 1.99
        - img 1.2
        - Tktable 2.5
        - snack 1.6
        - expect 5.28
        - Sybtcl (HP-UX only)
   Several of these extensions have been patched to deal with known
   problems.

   The VLT OCT99 release also provides the following Tcl/Tk based 
   utilities:
        - tclCheck 1.1.13
        - tkman 2.1b2 (with rman 3.0.7)

   The tkinspect utility is no longer part of the VLT Common SW
   release, as it does not support Tcl 8.0.

   Changes (with respect to FEB99):

     - there are several compatibility-issues as an upgrade to a new
       major Tcl/Tk release is involved. Most of these issues are
       described in the following WWW-documents:
             http://www.scriptics.com/software/8.0.html
             http://www.tcltk.com/itcl/itcl3-port.html

       The most relevant incompatibilities have been collected into
       a "compat" configuration file, as part of the compat-module
       version 1.20 or higher (compat/config/compat.TclTk8.config).
       Look at this file and the compat(n) manpage for more info.

       The following are "subtle" incompatibilities which cannot be
       caught by the compat utility; they all have to do with a
       clear-cut separation between lists and strings (while this
       boundary was much more diffuse in previous Tcl versions):

       * list operations on badly formed lists will fail, even if the
         "bad" element(s) is/are not accessed.
         Example: lrange {a b "c d"extra_char_after_quote f} 0 1

       * list operations on lists with multiple spaces between elements
         result in lists with single spaces.
         Example: lrange {a b     c d} 1 2

       * list elements containing starting/ending quotes will loose them
         (if no spaces are involved) or have them replaced by braces 
         during list operations.
         Example: lrange {a b c "d"} 2 end
                  lrange {a b c "d e"} 2 end 
 
     - there is a problem with "variable shadowing" in [incr Tcl],
       i.e. when a method argument has the same name as an object
       variable. This problem only appears when the argument is
       de-referenced within a "switch" statement". The solution is
       simple: make sure your method arguments do not have the same
       name as object variables, ie. do not rely on "shadowing".
       This problem is demonstrated by the following code-snippet:
           class Test {
	       private variable var {object variable}
	       public method varTest {var} {
                   puts "outside switch: var = $var"
                   switch -- 1 1 {puts "inside switch: var = $var"}
               }
           }
           [Test #auto] varTest "argument variable"



   New Features (with respect to FEB99):

     - Tcl/Tk 8.0 contains a byte-code compiler. Although it is not
       yet optimized, you should still see a performance improvement,
       whose magnitude depends on the instruction set used and the
       programming style. Typically applications may execute up to
       twice as fast.

     - Further explanations about additional new few features of Tcl/Tk
       and the extensions used can be found in the respective manpages 
       and WWW pages.


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