How to get a heap visualization

Erik de Castro Lopo mle+hs at
Wed Sep 20 02:37:04 UTC 2017

Ben Gamari wrote:

> Yitzchak Gale <gale at> writes:
> > Joachim, first and foremost, thanks for the awesome libraries
> > ghc-vis and ghc-heap-view.
> >
> > The design trade-offs for ghc-vis do make sense if you think of
> > it as a didactic tool. But as a debugging tool, the most important
> > factor is that it should "Just Work", with no big builds, no fiddling,
> > no googling. When you reach for a debugging tool, you are
> > *already* in a debugging situation; you don't have patience
> > for also debugging the tool.
> >
> I should point out that there is a differential (D3055) by erikd from
> earlier this year which folded ghc-heap-view into GHC. The goal was to
> make heap-view a supported library which could be relied upon by third
> party tools. As far as I can remember most of the hard work is done; it
> just needed some finishing touches. Perhaps you would be interested in
> picking it up?

Sorry if I gave the wrong impression, but IMO ghc-heap-view is a *long*
way from being ready to integrate into GHC. ghc-heap-view currently supports
most of the normal/simple heap object types. but has no support for more
complex objects. Furthermore, levity polymorphism adds a whole new dimension
to the problem. My estimate of the amount of work required to make ghc-heap-view
cover all the heap objects was such that I abandoned the project. I would
love to see someone pick it up and run with it.

Erik de Castro Lopo

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