README file for TDebug, an alternative tcl/tk-debugger.

The current Maintainer of TDebug is David Dougherty <david.dougherty@amd.com> 

Copyright (C) 1993 Gregor Schmid 

This software is copyrighted by Gregor Schmid. The following terms apply to all files associated with the software unless explicitly
disclaimed in individual files. 

The authors hereby grant permission to use, copy, modify, distribute, and license this software and its documentation for any purpose,
provided that existing copyright notices are retained in all copies and that this notice is included verbatim in any distributions. No written
agreement, license, or royalty fee is required for any of the authorized uses. Modifications to this software may be copyrighted by their
authors and need not follow the licensing terms described here, provided that the new terms are clearly indicated on the first page of
each file where they apply. 

IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR
ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. THIS
SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO
PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 

Files included in this distribution

    README older version of this file README.html this file TdChoose.tcl the TDebug front end TdDebug.tcl the debugger
    ChangeLog development history

General

TDebug uses a different approach than any other debugger I've seen for Tcl/Tk. If you know the emacs-lisp debugger `edebug' the
following may seem familiar. 

TDebug is solely based on Tcl/Tk, there is no C-code, which makes it very easy to install. It works by parsing and redefining
Tcl/Tk-procs, inserting calls to `td_eval' at certain points, which takes care of the display, stepping, breakpoints, variables etc. 

The advantages are that TDebug knows which statement in what proc is currently being executed and can give visual feedback by
highlighting it. All currently accessible variables and their values are displayed as well. Code can be evaluated in the context of the
current proc. Breakpoints can be set and deleted with the mouse. 

Unfortunately there are back-draws to this approach. Preparation of large procs is slow and due to Tcl's dynamic nature there is no
guarantee, that a proc can be prepared at all. 

This problem has been alleviated somewhat with the introduction of partial preparation of procs. There is still no possibility to get at code
running in global context, but I'm not sure if that would be useful anyway. 

News

New since version 1.5 (From David Dougherty) 

    Added new color control for more consistent display across application. 
    Added find field for procedure name searches, activated by <Return>. 
    Fixed a bug in breakpoint routine caused by embedded []{} characters.  It's still not perfect but much better. 
    README is now solely maintained in HTML (this file). 

New since version 1.0 

    Compatibility with Tcl8.0/Tk8.0 