[Hs-Generics] Re: Syb Renovations? Issues with Data.Generics

Claus Reinke claus.reinke at talk21.com
Thu Aug 21 04:10:27 EDT 2008

Some of you already know, but it seems I forgot to mention this here -
my code has moved to a darcs repo, with a little bit of documentation
and a README summarizing the issues. See my toolbox for more info:



It turned out to be tricky to recognize nested types at the
Data/Typeable level, let alone nested types that really have 
an infinite set of potential substructure types (which are the
ones that break the PlateData optimization).

Instead, I just count nesting levels (where nesting means that
we encounter the top-level type constructor while exploring
its substructure types), and set an arbitrary bound beyond
which I assume the nesting to be recursive and fall back to
the unoptimized case.

You might want to apply something similar to PlateData.


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