Last year, Andy Gill published his Haskell Object Observation Debugger, Hood, which provides for the selective observations of intermediate structures occurring in functional computations. Building on this work, I have been developing a tool for the graphical visualisation and animation of these observations. As should become clear in the presentation, this approach differs from more direct animations of program behaviour and sets out from a more abstract, extensional view of the program under observation. Nevertheless, experience so far indicates that interesting insights into program behaviour can be gained by careful interpretation of graphically animated observations, making GHood a useful item in the toolboxes of Haskell programmers and educators.
The slides of the talk and more information about GHood is available here.