STK : Second level

Programming with material shown before is a little bit tedious and more complicated than coding with Tcl since one have to add parenthesis pairs and quote options values. Its only interest is to bring the power and flexibility of Tk to the Scheme world.

The second level of STK is far more interesting since it uses a full object oriented extension of the Scheme language. Defining an object oriented layer on Scheme is a current activity in the Scheme community and several packages are available. The object layer of STK is derived from a package called Tiny Clos [#!Tiny-Clos!#]. This extension provides objects à la CLOS (Common Lisp Object System). In fact, the proposed extension is much closer from the objects one can find in Dylan, since this language is already a tentative to merge CLOS notions in a Scheme like language [#!Dylan!#].

STK object extension gives to the user a full object oriented system with multi-inheritance and generic functions. Furthermore, all the implementation rely on a true meta object protocol, in the spirit of [#!AMOP!#]. This model has been used to embody all the predefined Tk widgets in a hierarchy of Stk classes.



Subsections