The ghc-vis package

[Tags:bsd3, library]

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 for the basic usage of ghc-vis or watch a short video demonstrating how it can be used with GHCi's debugger:


Versions 0.1, 0.2, 0.2.1, 0.3, 0.3.1,, 0.3.2, 0.4, 0.5, 0.6, 0.6.1,, 0.7,, 0.7.1, 0.7.2,,,,,,,,,, 0.8
Dependencies base (==4.*), cairo (==0.12.*), deepseq, fgl, ghc-heap-view (>=, graphviz (>=2999.14.1.0), gtk (==0.12.*), mtl (>=2.0), SDL (>=0.6), svgcairo (>=0.12), text, transformers, xdot (>=0.2) [details]
License BSD3
Copyright Dennis Felsing 2012
Author Dennis Felsing <>
Maintainer Dennis Felsing <>
Stability Unknown
Category GHC, Debug, Development
Home page
Source repository head: git clone git://
Uploaded Mon Dec 3 23:23:41 UTC 2012 by DennisFelsing
Distributions NixOS:0.8
Downloads 4917 total (70 in the last 30 days)
1 []
Status Docs not available [build log]
All reported builds failed as of 2015-11-18 [all 6 reports]


  • GHC
    • GHC.Vis


graph"Enable graph view using Graphviz"EnabledAutomatic
full"Full ghc-vis window: decorations, buttons, legend"EnabledAutomatic
sdl"SDL window"DisabledAutomatic

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info


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