Arrowized Functional Reactive Program Visualization

The project presents a first proof of concept implementation of the idea to visualize the network of arrowized functional reactive programs. The advantage of arrowized reactive programs against other FRP systems is that they provide a well defined graphical representation by construction. The underlying representation immediately follows from the creation of the program via the core arrow operations as well as library specific primitives, such as switches and others.

To extract the program structure, our implementation does not run a static analysis of the source code, since this would introduce a huge implementation burden due to parsing requirements and so forth. Instead, we use the extendability of the arrow classes to create a wrapper arrow that extends the original arrow definition of the library with an observer that records the created network during creation. With this observer at hand, we then also created a wrapper module specific for the AFRP library, that provides the exact same interface. This way, the visualizer can be easily embedded, even into existing projects, by just importing the wrapper module instead of the original one. After creation, the network then can be plotted using one of the supported backends.

Supported Libraries

Yampa-0.11

Supported Rendering Backends

Tikz + pdflatex

Limitations

Due to their dynamic nature, we cannot visualize switches within the network to their full extend yet. Since the network that is switched to is dynamically created at runtime it's graphical representation is also only available at that point. Thus, at the moment we only support visualization of the network that is switched from, as this can be statically determined during the initial arrow creation.
Yampa's pause, rSwitch, kSwitch, and parallel switches are not supported yet.
Using specific methods from FRP.Yampa.(...) sub-modules is currently not supported (may work for some of the sub-modules, but not tested specifically yet).

Requirements

stack or cabal + ghc + package dependencies
pdflatex with tikz package
a Yampa program for visualization that supports Yampa-0.11

Usage

Replace all imports of FRP.Yampa in your program with AFRPV.Yampa.
Use the new function renderNetwork to plot the signal function (see the haddock documentation for details).
You also may run the legend executable to get a short explanation of the different visualized primitives. Executing the tool creates an overview PDF under `legend/legend.pdf"

kleinreact / AFRPV