Restructuring SDL to improve readability

This thesis was written by Ole Henrik Dahle, as a part of a Cand. Scient. (Master of Science) degree at the Institute For Informatics, University of Oslo. The theoretical studies were done in 1998, and the programming and writing was done during the fall and winter of 1998/99. The programming and experiments were done at Ericsson NorARC (Norway Applied Research Center).

I would especially like to thank my supervisor, Řystein Haugen, fsor, Řystein Haugen, for being a great help in my work. Not only has he guided and encouraged me, but also helped me with many practical things. I would like to thank all the people at Ericsson NorARC for letting me work there. I would also like to thank Hans Steller and the people at Ericsson's PSTN (Public Switched Telephone Network) group for letting me participate in their TTM3 project.


This thesis shows how to use techniques and theory from program transformation to improve readability of SDL (Specification and Descrip tion Language) diagrams. An introduction to software reengineering in general and restructuring and transformation in particular is provided to establish the relationship between transformation and pretty printing. I then introduce a set of rules for readable SDL. To demonstrate the appli cability of these rules, I have created a prototype program that enforces the rules. A real world example, from a project in Ericsson, is fed through the program and the results are evaluated.

Keywords: Restructuring, program transformation, pretty printing, SDL, readability

Contents on this webpage

Copyright © 1999 Ole Dahle.
The source code is released under the GNU General Public Licence (GPL).
You may contact me at ole thesign no spam please dahle dot no.