I have three small questions.
1.
Haskell-98 description
- is it ready to print as the final, accepted and approved document?
2.
Question by Jose Emilio Labra Gayo <[EMAIL PROTECTED]>:
> Is it better to type the derived methods inside the class
> definition or out? Are there any efficiency penalties
> in any of the styles?
> [...]
Here is the concrete example (sorry, if i miss the point):
class Num' a where add,sub :: a -> a -> a
neg :: a -> a
sub x y = add x (neg y)
What might be the cost overhead (depending on implementation!),
if we move sub to separate polymorphic function:
sub :: Num' a => a -> a -> a
sub x y = add x (neg y)
For, personally, i do not like many operations per class.
3.
Module export:
if a module N has to export only a couple of instances for the
constructor defined in M, how does it say that nothing else is for
export?
Thus, in the following example, one has to hide
localThing1, localThing2:
module M ( C(..), ... )
where
data C a = ...
-------------------
module N ( ?? )
where
import M (C(..))
instance ...=> I1 (C a) where c x = localThing1 x
instance ...=> I2 (C a) ...
localThing1 = ...
localThing2 = ...
Probably, module N (C(..)) will do. Have we really to re-export C ?
Thank you in advance for the help.
------------------
Sergey Mechveliani
[EMAIL PROTECTED]
