🚀 go-pugleaf

Hello,

The following is not a homework question, just something that has been
testing my patience. I have an algorithm that sorts a list of pairs. Say one
instance of the input is of type,

:: ((a,a),(a,a))

I find that if I use the derived ordering it sorts, but the result is not
what I want. I want to introduce an ordering based on a function I already
have. For example a metric on the above input with type,

:: Floating a => ((a,a),(a,a)) -> a

My understanding is that I should be able to achieve this by operator
overloading. I have looked at both the gentle intro and the Hugs prelude but
have just not had much success expressing it precisely in Haskell.

An example from any of you would be greatly appreciated.

  Thanks in advance