ghc-vis

Visualize live data structures in GHCi. Evaluation is not forced and you can interact with the visualized data structures. This allows seeing Haskell's lazy evaluation and sharing in action. See http://felsin9.de/nnis/ghc-vis/#basic-usage for the basic usage of ghc-vis or watch a short video demonstrating how it can be used with GHCi's debugger: http://felsin9.de/nnis/ghc-vis/#combined-debugger