resemble a formal specification. For a couple of examples, see my RangedSet package and Neil Mitchel's FilePath package. I manually copied the RangedSet tests into the Haddock documentation, while Neil wrote a small Haskell script to extract his tests from his documentation automatically. Unfortunately his script is tied to specific aspects of his FilePath package.
Yes, the problem was that FilePath wants to execute half the tests twice with different modules, and half with just one namespace. As far as tests go, this is a very wacky requirement. I wanted to generalise it into a tool, but couldn't find a sensible generalisation that still worked with filepath - and hence didn't bother. I think the solution is to not permit the quirkyness of filepath, and write a general solution for everything else.
Niel -- I understand your script is part of FilePath... might it be a good starting point for abstraction? Can you point me to it?
As someone who has frequently considered writing this, even going as far as brainstorming on a whiteboard, I would be an enthusiastic user of this. I think the lack of this tool in Haskell is a big hole which someone needs to fill. I particularly like the facility in FilePath:
-- > x == reverse (reverse x) -- > reverse "neil" = "lien"
i.e. I can write both quickcheck properties (quantified over all single letter variables), or I can write an instance (like doctest in Python)
Thanks, and good luck!
Neil
Thank you for the support... This might take me a while, I must warn, as this is an "after work" project, and I am a consultant, so "after work" often doesn't come :). But its certainly motivating to work on something right away that could be useful (to myself as well). - Shaun