[Haskell-cafe] What symbol / atom/ interned-string package is currently preferred?

[Johannes Waldmann]

> https://github.com/ekmett/intern/blob/master/examples/Term.hs

sure I found this but that still does not say much.

I known generally what "hash consing" is 
(and that's why I think I might want to use this package)
but I don't see what is the (implied) contract for this implementation:
It looks like I need to write some instances 
(to make my typ "internable") but what properties should they have, 
and what properties of the functions defined in the package 
do I get in return?

- J.W.