On Tue, Apr 17, 2012 at 6:40 PM, Nicolas Frisby wrote:
> I built a (really ugly) dictionary for (Int ~ Char) using
> Data.Constraints.Forall. I'm fairly confident it could be generalized
> to a polymorphic coercion (a ~ b).
>
> http://hpaste.org/67180
>
> I cheated with overlapping instances, but
On Mon, Apr 16, 2012 at 6:57 PM, Nicolas Frisby wrote:
> I'm simulating skolem variables in order to fake universal
> quantification in constraints via unsafeCoerce.
>
> http://hpaste.org/67121
>
> I'm not familiar with various categories of types from the run-time's
> perspective, but I'd be sur
On Tue, Mar 13, 2012 at 4:57 AM, Simon Marlow wrote:
> On 12/03/2012 14:22, Edward Kmett wrote:
>
>> On Mon, Mar 12, 2012 at 6:45 AM, Simon Marlow > <mailto:marlo...@gmail.com>> wrote:
>>But I can only pass unboxed types to foreign prim.
>>
>>
On Mon, Mar 12, 2012 at 6:45 AM, Simon Marlow wrote:
> But I can only pass unboxed types to foreign prim.
>>
>> Is this an intrinsic limitation or just an artifact of the use cases
>> that have presented themselves to date?
>>
>
> It's an intrinsic limitation - the I# box is handled entirely at t
I'm currently working with a lot of very short arrays of fixed length and
as a thought experiment I thought I would try to play with fast numeric
field accessors
In particular, I'd like to use something like foreign prim to do something
like
> foreign import prim "cmm_getField" unsafeField# :: a
Not sure if I misparsed your response or not.
Its not just things that can or could match the type of the scope, but
basically anything introduced in local scopes around the hole, those can
have types that you can't talk about outside of a local context, due to
existentials that were opened, etc.
On Tue, Feb 14, 2012 at 11:18 AM, Iavor Diatchki
wrote:
> Hello,
>
> On Mon, Feb 13, 2012 at 5:32 PM, Edward Kmett wrote:
>>
>> There are fewer combinators from commonly used classes for working with
>> the left argument of a bifunctor, however.
>>
>
> I
Sent from my iPhone
On Feb 14, 2012, at 3:00 AM, Roman Leshchinskiy wrote:
> On 13/02/2012, at 11:10, Simon Peyton-Jones wrote:
>
>> | Should there perhaps be a NewTypeable module which could then be renamed
>> | into Typeable once it is sufficiently well established?
>>
>> I started with
On Mon, Feb 13, 2012 at 3:27 PM, Simon Marlow wrote:
> On 13/02/12 18:16, Edward Kmett wrote:
>
>> You could probably get away with something like
>>
>> data Proxy = Proxy a
>>
>> class Typeable a where
>> typeOfProxy :: Proxy a -> TypeRep
>>
You could probably get away with something like
data Proxy = Proxy a
class Typeable a where
typeOfProxy :: Proxy a -> TypeRep
typeOf :: forall a. Typeable a => a -> TypeRep
typeOf = typeOfProxy (Proxy :: Proxy a)
which being outside of the class won't contribute to the inference of 'a's
kind.
In practice I've found that working with Tagged is a huge pain relative to
working with Proxy.
You usually need to use ScopedTypeVariables or do asTypeOf/asArgOf tricks
that are far more complicated than they need to be.
For reference you can compare the internals of reflection before when it
use
I can live with it and I probably have as many packages as anyone that will
be broken by it. =/
Things like
http://hackage.haskell.org/packages/archive/categories/0.58.0.5/doc/html/src/Control-Category-Cartesian-Closed.html
will need a pretty invasive rewrite, but the simplicity is worth it, an
Great! This will greatly reduce the boilerplate in the constraints package.
Sent from my iPhone
On Jan 16, 2012, at 9:15 AM, Simon Peyton-Jones wrote:
> | /tmp/Test.hs:4:1:
> | The multi-parameter class `C' cannot have generic methods
> | In the class declaration for `C'
>
> Aha.
P, however.
Or rather, if it does, the methodology it would lead to would be one of
bringing over all of their internals into Haskell. ;)
-Edward Kmett
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
On Sun, Jan 8, 2012 at 8:32 AM, Bas van Dijk wrote:
> On 23 December 2011 17:44, Simon Peyton-Jones
> wrote:
> > My attempt at forming a new understanding was driven by your example.
> >
> > class Functor f where
> >type C f :: * -> Constraint
> >type C f = ()
> >
> > sorry -- that was s
On Fri, Dec 23, 2011 at 10:17 AM, Simon Peyton-Jones
wrote:
> Right now it seems it is either * or Constraint depending on context. ***
> *
>
> ** **
>
> Correct. Tuple bracket are used for both types and Constraints, and we
> have to decide which from context.
>
> **
>
Whew, that agrees
to:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Edward Kmett
> Sent: 22 December 2011 17:03
> To: Bas van Dijk
> Cc: glasgow-haskell-users@haskell.org
> Subject: Re: ConstraintKinds and default associated empty constraints
>
> On Wed, Dec 21, 2011 at 6:45 PM, Bas van
7.0.x agrees with the standard.
The change, however, was a deliberate _break_ with the standard that passed
through the library review process a few months ago, and is now making its way
out into the wild.
The simplest fix is to simply add an Eq or Show constraint to the few functions
that ne
On Wed, Dec 21, 2011 at 6:45 PM, Bas van Dijk wrote:
> I'm playing a bit with the new ConstraintKinds feature in GHC
> 7.4.1-rc1. I'm trying to give the Functor class an associated
> constraint so that we can make Set an instance of Functor. The
> following code works but I wonder if the trick wi
Sent from my iPad
On Nov 15, 2011, at 7:18 PM, wren ng thornton wrote:
> On 11/15/11 12:33 PM, Yitzchak Gale wrote:
>> Simon Peyton-Jones wrote:
>> Trouble is, what type does this have?
>> f x = x {}
>>
>> Malcolm Wallace wrote:
> f :: a -> a
>>
>> Ian Lynagh wrote:
That
Ian said
>class Has (r :: *) (ft :: *) (f :: ft) (t :: *) where
> (where ft stands for field type)?
>
class Has (r :: *) (f :: ft) (t :: *) where
would be my understanding of how it would be phrased under the current
polymorphic kind system.
This could also solve the representation-hidi
On Mon, Nov 7, 2011 at 1:33 PM, Wolfgang Jeltsch wrote:
> Am Montag, den 07.11.2011, 18:16 +0100 schrieb Claus Reinke:
> > > I am unsure which of this list of proposals you are referring to. The
> > > URL you quote is this
> > > http://hackage.haskell.org/trac/haskell-prime/wiki/FirstClassLabels
The major concern that I would have is that if GCL or any of those math
libraries uses GMP behind the scenes, which they probably do, then things
will just start crashing on you, because GHC hooks the GMP allocator and
will just start making the limbs of their numbers disappear.
-Edward
On Tue, N
If you use lenses you can do this today with no real need to adulterate the
parser.
setL (l2 . l1) x rec
This goes one step further as it can be written point free so you don't even
have to give rec a name if you don't want to. ;)
-Edward
On Mon, Sep 19, 2011 at 9:09 AM, Barney Hilken wrote:
>
On Thu, Sep 1, 2011 at 8:49 AM, Simon Marlow wrote:
> On 01/09/2011 08:44, Evan Laforge wrote:
>
>> Yes, the plan was to eventually have a parallel --make mode.
>>>
>>
>> If that's the goal, wouldn't it be easier to start many ghcs?
>>
>
> It's an interesting idea that I hadn't thought of. There
It would still be nice to have a consistent base case.
On Mon, Aug 22, 2011 at 3:43 AM, Johan Tibell wrote:
> On Mon, Aug 22, 2011 at 5:55 AM, Edward Z. Yang wrote:
> > stg_newArrayzh in rts/PrimOps.cmm doesn't appear to give any indication,
> > so this might be a good patch to add. But I'm cur
On Mon, Jul 25, 2011 at 1:40 PM, Jacques Carette wrote:
> **
> On 25/07/2011 9:55 AM, Edward Kmett wrote:
>
> If you have an associative (+), then you can use (.*) to multiply by a
> whole number, I currently do fold a method into the Additive class to
> 'fake' a
2011/7/25 Gábor Lehel
> > type family Frozen t
> > type family Thawed t
> > class Immutable (Frozen t) => Mutable t where
> > thawedFrozen :: t -> Thawed (Frozen t)
> > unthawedFrozen :: Thawed (Frozen t) -> t
> >
> > class Mutable (Thawed t) => Immutable t where
> > frozenThawed :: t -> Fr
On Mon, Jul 25, 2011 at 4:46 AM, Simon Peyton-Jones
wrote:
> On further reflection I have a question.
>
> ** **
>
> Under the limited design below, which Edward says will do all he wants:***
> *
>
> **· **The mutually recursive classes (call them A, B, C) must be
> defined all togethe
2011/7/23 Gábor Lehel
> 2011/7/22 Dan Doel :
> > 2011/7/22 Gábor Lehel :
> >> Yeah, this is pretty much what I ended up doing. As I said, I don't
> >> think I lose anything in expressiveness by going the MPTC route, I
> >> just think the two separate but linked classes way reads better. So
> >> i
2011/7/22 Simon Peyton-Jones
> I talked to Dimitrios. Fundamentally we think we should be able to handle
> recursive superclasses, albeit we have a bit more work to do on the type
> inference engine first.
>
> The situation we think we can handle ok is stuff like Edward wants (I've
> removed all
y unsatisfying because the Natural and Integer
multiplication become horrific, and I wind up having to multiply the code
below this point in the hierarchy to deal with the 'self algebra' cases. =/
I've also run into the problem about once or twice a year when encoding
other concepts t
101 - 132 of 132 matches
Mail list logo
