[Haskell-cafe] Re: Tree Guidance

[apfelmus]

Chris Kuklewicz wrote:
> apfelmus wrote:
>> Up-pointers won't work in Haskell, you'll need a different approach. Can
>> you elaborate on what your tree looks like and what it stores?
> 
> "pointers" don't exist in Haskell, though they do exist in the Foreign.*
> interface package.
> 
> But Up-values work just fine:

Well, not really: they're read-only. To "update" a single Branch/Leaf in
the presence of up-values/"pointers" requires to update the up-values of
_every_ Branch/Leaf in the tree.

Regards,
apfelmus