A tool for debugging compiler optimizations and type inference (in deutscher Sprache)
The focus of this talk will be type theory (type system and type inference), applied to a dynamic language (Slides of a previous talk are ). A side-effect during working on this topic was the development of a visualization tool:
This tool is a Java application which visualizes the control and data flow graph of the intermediate representation of Open Dylan  (former DylanWorks, Harlequin Dylan, Functional Developer) and animates optimizations. The Open Dylan compiler was extended with hooks to send control flow and data flow changes via TCP/IP to the Java application. The justification why the visualization is in Java is because I couldn't find a decent graph layouting and animation library with an API. The graph library used is yFiles . The Java code  consists of 2000 lines of code, the compiler hooks were about 250 lines of code. The communication protocol in use are S-expressions, in the same marshalling format as swank (the slime backend protocol).
An example for this work is a visualized map(method(x) x end, #(1)), available at  (data flow nodes and edges are pink).
25. Juni 2009, 20 Uhr im CCCB, Marienstr. 11, 10117 Berlin