This package provides the basic facilities for combining the
programming languages Eiffel and tcl into a hybrid program architecture.

The basic concept of this package is the idea of writing the body of a 
program in Eiffel (which is safe, elegant and maintainable), export the 
essential routines and data to tcl in order to finally create the appli-
cations interface with xf which is fast development and grants a high 
degree of adaptability. It is even imaginable to have the final users of 
your product re-design parts of or even the whole human computer interface 
to their taste including the possibility to write and bind macros, that on a s
ingle mouse click execute (complex) standard sequences of their work.

What you need is:
	ISE Eiffel 3 (only base library required - I tried with 3.1.1)
	tcl 7.3 or later
	tk 3.6 or later

The approach is as follows (caution: technical details below):

eif_tcl.c contains the functions to interface from Eiffel to the tcl
	library (which is a C-library). eif_tcl.c is encapsulated by the 
	Eiffel classes TCL_INTERPRETER, TK_INTERPRETER and TCL_COMMAND.

TCL_INTERPRETER encapsulates the interpreter itself.
TK_INTERPRETER (a specialization of TCL_INTERPRETER) adds tk capability
TCL_COMMAND defines a protocoll for Eiffel routines that can be
	installed into a tcl interpreter under a name that will then
	serve as a new tcl command callable from within this interpreter.
	A mechanism for passing arguments from tcl to Eiffel is provided, too.

TCL_OBJ is a small example for an application class which uses a tcl-tk
interpreter for its visualization. It has two variables which are mapped
to tcl variables. The routines `to_tcl' and `from_tcl' manage the data 
transfer. Additionaly TCL_OBJ creates some TCL_COMMANDS as instances of
different specializations like CREATE_CMD etc. These commands are associated
to the TCL_OBJ object and installed into the interpreter. Finally a
tcl script is executed "tcltest.tcl".

In tcltest.tcl (which is purely generated by means of xf) finally a
window is defined containing: 
    - 2 text entries that are associated to the tcl variables "var1" and
      "var2". TCL_OBJ uses these variables for data transfer.
    - a menue and four command buttons associated to the commands
      "new_win", "defaults", "print", "donnot", "close_win", "my_eval"
      These commands evaluate as callbacks to Eiffel.
(Notice the button "eval $var1": when you press this button the
contents of the first text entry is interpreted as a tcl command. E.g.
try typing:
puts "Hello $var2"
push the button and watch the output in your Xterm. Or you might try
"destroy ." which is a tk command 
or try one of the commands "new_win", "defaults" etc.. Special
interest to "print" with any number of arguments - watch your Xterm).

Hope you enjoy it
Stephan
(stephan@cs.tu-berlin.de)