Type family Normalize does not always reach fix point

[bruderj15]

In Servant.Hateoas.Layer there is below type-family for normalizing an API to a shared prefix form:

type family Normalize api where
  Normalize ((prefix :> a) :<|> (prefix :> b)) = Normalize (prefix :> (Normalize a :<|> Normalize b))
  Normalize (a :<|> b)                         = Normalize a :<|> Normalize b
  Normalize ((prefix :> a) :>   (prefix :> b)) = Normalize (prefix :> (Normalize a :>   Normalize b))
  Normalize (a :> b)                           = a :> Normalize b
  Normalize a                                  = a

Normalize (a :<|> b) = Normalize a :<|> Normalize b may lead to a common prefix and therefore needs to be applied again.
However just applying Normalize (Normalize a :<|> Normalize b) obviously results in a loop.
We need a better way to apply Normalize until a fix-point is reached.

[bruderj15]

I wonder if we need the normalization at all.
We already apply MergeLayers from Servant.Hateoas.Layer.Merge which gets rid of the multiple Layers for the same endpoint problem.