In a software reengineering task legacy systems are adapted computer-aided to new requirements. For this an efficient representation of all data and information is needed. TGraphs are a suitable representation because all vertices and edges are typed and may have attributes. Further more there exists a global sequence of all graph elements and for each vertex exists a sequence of all incidences. In this thesis the "Extractor Description Language" (EDL) was developed. It can be used to generate an extractor out of a syntax description, which is extended by semantic actions. The generated extractor can be used to create a TGraph representation of the input data. In contrast to classical parser generators EDL support ambiguous grammars, modularization, symbol table stacks and island grammars. These features simplify the creation of the syntax description. The collected requirements for EDL are used to determine an existing parser generator which is suitable to realize the requirements.
After that the syntax and semantics of EDL are described and implemented using the suitable parser generator. Following two extractors one for XML and one for Java are created with help of EDL. Finally the time they need to process some input data is measured.
TGraphBrowser
(2010)
This thesis describes the implementation of a web server that enables a browser to display graphs created with the Java Graph Laboratory (JGraLab). The user has the choice between a tabular view and a graphical presentation. In both views it is possible to navigate through the graph. Since graphs with thousands of elements may be confusing for the user, he or she is given the option to filter the displayed vertices and edges by their types. Furthermore, the number of graph elements shown can be limited by means of a GreQL query or by directly entering their ids.
