Search by Type

Here's a random thought. What if we had a way to search for Haskell functions by type signature. Take the Hierarchical Libraries, slice/dice/index the type signatures so that you could search for "Num b => a -> b" and it would present you with a list of functions like length :: [a] -> Int. You'd also probably want to allow swizzling of the input arguments so that you could find "map" with a search like "[a] -> (a -> b) -> [b]". Then the next step would be to analyze your existing code to see if you've reinvented any wheels.