Hello Jan-Willem,
Wednesday, February 08, 2006, 4:26:48 PM, you wrote:
JWM> Should there be a class which is implemented by every well-formed
JWM> type of kind (*)? Should that class have one or more of the following:
JWM>* Structural decomposition and reconstruction a la Generics?
JWM>*
On Feb 7, 2006, at 11:45 PM, John Meacham wrote:
Ashley Yakeley has convinced me this proposal won't work as is. I knew
that dropping of the a type parameter in the dictionary passing scheme
would bite me :). though, perhaps it will inspire another proposal? In
the meantime, I will see about im
In article <[EMAIL PROTECTED]>,
John Meacham <[EMAIL PROTECTED]> wrote:
> Ah. I think I see the objection now. Will have to think about it some.
Here's a simpler example:
class HasInt a where
getInt :: a -> Int
instance HasInt Int where
getInt = id
newtype HasInt a => T a = T
Ashley Yakeley has convinced me this proposal won't work as is. I knew
that dropping of the a type parameter in the dictionary passing scheme
would bite me :). though, perhaps it will inspire another proposal? In
the meantime, I will see about implementing the 'wft' constraints as
mentioned in the
Ah. I think I see the objection now. Will have to think about it some.
John
--
John Meacham - ⑆repetae.net⑆john⑈
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I'll give the full desugaring, perhaps that will make it more clear:
> foo :: (Monad m) => m Int
> foo = return id >>= (\i -> return (i 7))
>
> fooSet :: Set Int
> fooSet = foo
mkMonadDictSet :: EqDict a -> MonadDict Set
eqDictInt :: EqDict Int
return :: MoandDict m -> a -> m a
foo :: Mona
On Tue, Feb 07, 2006 at 07:59:46PM -0800, Ashley Yakeley wrote:
> John Meacham wrote:
>
> >however, (Set (a -> a)) is malformed. since a _requirement_ is that Set
> >can only be applied to a type with an Eq constraint so the instance you
> >try to do something like
> >
> >returnid :: Set (a -> a)
John Meacham wrote:
however, (Set (a -> a)) is malformed. since a _requirement_ is that Set
can only be applied to a type with an Eq constraint so the instance you
try to do something like
returnid :: Set (a -> a) -- ^ static error! you need
returnid :: Eq (a -> a) => Set (a -> a)
the instant
On Tue, Feb 07, 2006 at 05:54:51PM -0800, Ashley Yakeley wrote:
> John Meacham wrote:
>
> >newtype Eq a => Set a = Set (List a)
> >singleton :: Eq a => a -> Set a
> >class Monad m where
> >return :: a -> m a
> >
> >instance Monad Set where
> >return x = singleton x
> >
> >okay, our
John Meacham wrote:
newtype Eq a => Set a = Set (List a)
singleton :: Eq a => a -> Set a
class Monad m where
return :: a -> m a
instance Monad Set where
return x = singleton x
okay, our goal is to make this typesafe.
You shouldn't be able to, should you? Monad makes a promis
I am trying to reformulate restricted data types such that they can
easily be implemented by jhc and possibly standardized independent of
the implementation method and would like to run what I have so far by
the list. Unlike the original paper, I will treat the user-visible
changes to the type syst
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