On Wed, Apr 14, 2010 at 08:44:29PM +0200, Matthias Kilian wrote:
module Main(main) where
import System.IO
import System.Process
main = do
hin - openBinaryFile /dev/null ReadMode
hp - runProcess /bin/ls [-l] Nothing Nothing (Just hin)
Nothing Nothing
Dear GHC experts,
Certain behaviour when using
{-# LANGUAGE GADTs, TypeFamilies #-}
surprises me. The following is accepted by GHC 6.12.1:
data GADT a where
BoolGADT :: GADT Bool
foo :: GADT a - a - Int
foo BoolGADT True = 42
But the following is not:
data family
Hi Sebastian,
Is this perhaps another instance of #3851?
http://hackage.haskell.org/trac/ghc/ticket/3851
Cheers,
Pedro
On Thu, Apr 15, 2010 at 14:10, Sebastian Fischer
s...@informatik.uni-kiel.de wrote:
Dear GHC experts,
Certain behaviour when using
{-# LANGUAGE GADTs, TypeFamilies
Is this perhaps another instance of #3851?
http://hackage.haskell.org/trac/ghc/ticket/3851
Honestly: I don't know.
My example is different from the one shown in #3851 in that it also
does not work in GHC 6.10 (which even panics instead of giving the
error 6.12 gives) and in that it uses a
Hi Sebastian,
On Thu, Apr 15, 2010 at 15:08, Sebastian Fischer
s...@informatik.uni-kiel.de wrote:
Is this perhaps another instance of #3851?
http://hackage.haskell.org/trac/ghc/ticket/3851
Honestly: I don't know.
My example is different from the one shown in #3851 in that it also does
but later in the comments I show an example with data families
which fails on both 6.10.4 and 6.12.1.
Ah, I think I misinterpreted your comment, when I read it for the
first time. Thanks for pointing me at it again. But I still don't see
whether or not the two examples are related. At
Sebastian Fischer wrote:
Dear GHC experts,
Certain behaviour when using
{-# LANGUAGE GADTs, TypeFamilies #-}
surprises me. The following is accepted by GHC 6.12.1:
data GADT a where
BoolGADT :: GADT Bool
foo :: GADT a - a - Int
foo BoolGADT True = 42
On Thursday 15 April 2010 8:10:42 am Sebastian Fischer wrote:
Dear GHC experts,
Certain behaviour when using
{-# LANGUAGE GADTs, TypeFamilies #-}
surprises me. The following is accepted by GHC 6.12.1:
data GADT a where
BoolGADT :: GADT Bool
foo :: GADT a - a
With GADTs, the specific choice of constructor is what gives you the
type matching functionality.
My intention was to use a GADT as data family instance (hence, I wrote
it in GADT style and it was accepted as such). Can't GADTs be used as
data family instances?
Sebastian
--
Sebastian Fischer wrote:
With GADTs, the specific choice of constructor is what gives you the
type matching functionality.
My intention was to use a GADT as data family instance (hence, I
wrote it in GADT style and it was accepted as such). Can't GADTs be
used as data family instances?
On Apr 15, 2010, at 3:44 PM, Sittampalam, Ganesh wrote:
You were trying to choose between different top-level types (which
happen to be instances of the same family) by their constructors.
That is true. I was trying to emulate an open data type such that I
can write
-- does not work
I think the baseline ellipsis makes much more sense; it's
hard to see how the midline ellipsis was chosen.
--
Jason Dusek
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My opinion is that we should either use TWO DOT LEADER,
or just leave it as it is now, two FULL STOP characters.
Two dots indicating a range is not the same symbol
as a three dot ellipsis.
Traditional non-Unicode Haskell will continue to be
around for a long time to come. It would be very
That is very interesting. I didn't know the history of those characters.
If we can't find a Unicode character that everyone agrees upon,
I also don't see any problem with leaving it as two FULL STOP
characters.
I agree. I don't like the current Unicode variant for .., therefore
I suggested an
While alloca is not as cheap as, say, C's alloca, you should find that
it is much quicker than C's malloc. I'm sure there's room for
optimisation if it's critical for you. There may well be low-hanging
fruit: take a look at the Core for alloca.
The problem with using the stack is that
Many choices were suggested! For now, I have decided to go with stow.
I installed 3 versions of GHC in /usr/local/stow, and installed
cabal-install locally (i.e. to my home directory), built with ghc
6.12.1. I'm not sure that this is the best way to go about this, but
it's what I'm working with
| My intention was to use a GADT as data family instance (hence, I
| wrote it in GADT style and it was accepted as such). Can't GADTs be
| used as data family instances?
|
| I'm not aware of any restriction there, but that's not the issue here.
|
| You were trying to choose between different
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