Tycho - A Heterogeneous Syntax Manager

Researchers: Edward A. Lee
Christopher Hylands
John Reekie
Advisor:Edward A. Lee

Tycho [1] is an object-oriented syntax manager with an underlying heterogeneous technical rationale. The Ptolemy software system, which has been under development at U.C. Berkeley since 1990, addresses the problem of mixing "models of computation," or semantic models. Thus, Ptolemy supports various dataflow models, discrete-event simulation, finite-state machine models, and others. The Tycho software system, under development since 1995 as a part of the Ptolemy project, provides a similar level of support for the syntactic component of system design: a designer can rapidly construct a user interface containing various syntactic representations of different semantic models.

Tycho provides a number of textual and graphical editors in an extensible, reusable framework. It incorporates architectural features designed to facilitate multiple, coordinated views of complex and dynamically-evolving data. As well as a hypertext documentation system and a suite of graphical widgets, text tools, and interfaces to development tools, Tycho includes an enhanced graphical canvas designed to support modular, hierarchical construction of visual editors. Although designed primarily for use with the Ptolemy system, Tycho is also an opportunity to experiment with new forms of mixed visual and textual syntaxes for design representation and understanding. Tycho has been used extensively in the development of the Tycho software itself.

Tycho's user interface components are written primarily in Itcl, also called [incr Tcl], developed by Michael McLennan of Lucent Technologies. Itcl is an object-oriented extension of Tcl, a "tool command language" written by John Ousterhout of U.C. Berkeley. Tycho interfaces both with the existing C++ Ptolemy kernel, and to new simulation development work being done within the Ptolemy group in Java.

Christopher Hylands, Edward A. Lee, and H. John Reekie, "The Tycho User Interface System," Proc. 5th Annual Tcl/Tk Workshop '97, Boston, Massachusetts, July 14-17, 1997, pp 149-157.