2008/2/19 Wolfgang Jeltsch <[EMAIL PROTECTED]>:
> Attached is just a quickly hacked Boolean module. Nothing very special. I'd
> be happy if you could prettify this (choose better names, add documentation,
> etc.). Thanks for any effort.
Thanks to you for the module. I have a few questions though.
Why are the value-level reflecting functionsimplemented as type-class
methods? It makes the code more verbose and I don't see any advantage
compared to simply defining a function per class. Let me show you an
example:
This is your implementation of Not:
class (Boolean boolean, Boolean boolean') =>
Not boolean boolean' | boolean -> boolean', boolean' -> boolean where
not :: boolean -> boolean'
instance Not False True where
not _ = true
instance Not True False where
not _ = false
This is how I would do it:
class (Boolean boolean, Boolean boolean') =>
Not boolean boolean' | boolean -> boolean', boolean' -> boolean where
instance Not False True
instance Not True False
not :: Not a b => a -> b
not = undefined
Furthermore, why did you choose to use Boolean instead of simply Bool?
Cheers,
Fons
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