[Haskell-cafe] manage effects in a DSL

Daniel Trstenjak daniel.trstenjak at gmail.com
Mon Feb 10 19:47:33 UTC 2014


Am 10.02.2014 um 17:26 schrieb Dominique Devriese <dominique.devriese at cs.kuleuven.be>:
> I disagree. Just think about the Ord type class.  A decidable order
> relation for a type is definitely something I would consider a clear
> semantical meaning ...

Why shouldn't be the kind of ordering part of the semantical meaning of Ord?

Otherwise what could you then say about the result of the 'sort' function?

  sort :: Ord a => [a] -> [a]


My gut feeling is, that if the effective range of the active instance is too narrow,
then it's not very useful, but if you widen it, then you're getting all of the possible 
drawbacks.


Greetings,
Daniel


More information about the Haskell-Cafe mailing list