[Haskell-cafe] Ordering TypeRep from Data.Typeable.
sergueyz at gmail.com
Thu Aug 26 13:42:58 EDT 2010
I think, that TypeRep type from Data.Typeable needs Ord class instance.
It is unnecessary, but is handy when needed.
My use case follows.
I try to create graph whose node and arc labels are differently typed.
So I can add Int node, Float node and link them by Conversion arc.
Right now I am quite good with GADTs that hide values of different types.
But when I thinking about querying that structure, I start to want
ordered TypeRep. I then can collect different arcs and nodes into
different sets and speed up query processing dramatically.
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