, there's no attempt to prove that:
forall (P Q : forall a, a - a), P = Q.
which is what parametricity means to me.
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Please let me know if there's any further trouble I can give you.
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On Mon, May 18, 2009 at 10:06 PM, Ryan Ingram ryani.s...@gmail.com wrote:
On Mon, May 18, 2009 at 3:05 PM, Taral tar...@gmail.com wrote:
Will this do?
(=) :: (NFData sa, NFData b) = LI sa - (sa - LI b) - LI b
No, the problem is that = on monads has no constraints, it must have the
type
LI
On Mon, May 18, 2009 at 10:30 AM, Nicolas Pouillard
nicolas.pouill...@gmail.com wrote:
The type I would need for bind is this one:
(=) :: NFData sa = LI sa - (sa - LI b) - LI b
Will this do?
(=) :: (NFData sa, NFData b) = LI sa - (sa - LI b) - LI b
--
Taral tar...@gmail.com
Please let me
On 3/12/08, Neil Mitchell [EMAIL PROTECTED] wrote:
However, I don't believe this expression is type safe in Haskell.
Using higher-order polymorphism:
f (x :: forall a. a - a) = x x
--
Taral [EMAIL PROTECTED]
Please let me know if there's any further trouble I can give you.
-- Unknown
On 2/27/08, Chad Scherrer [EMAIL PROTECTED] wrote:
Is {-# LANGUAGE MagicHash #-} documented somewhere? I've seen it referenced a
few times now, but I can't find any details about it.
No. http://hackage.haskell.org/trac/ghc/ticket/1297
--
Taral [EMAIL PROTECTED]
Please let me know if there's
)
(nth (- n 1) (tail xs (t nil)))
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evaluation order, amongst other
things. Hm... thank you very much!
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Please let me know if there's any further trouble I can give you.
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On Sat, Feb 23, 2008 at 1:05 AM, [EMAIL PROTECTED] wrote:
reset ((\x - x + x) (shift f f))
This one doesn't typecheck, since you can't unify the types (a - r) and r.
--
Taral [EMAIL PROTECTED]
Please let me know if there's any further trouble I can give you.
-- Unknown
My understanding of these things is limited, but what would stop me,
theoretically speaking, of making a version of ghc with these
primitives added:
type Prompt r
reset :: (Prompt r - r) - r
shift :: Prompt r - ((a - _) - r) - a
(Where _ is either r or forall b. b)
--
Taral [EMAIL PROTECTED
On 2/22/08, Taral [EMAIL PROTECTED] wrote:
reset :: (Prompt r - r) - r
shift :: Prompt r - ((a - _) - r) - a
The point of the question is about shift/reset with *these types*. I
know there are implementations with other types.
--
Taral [EMAIL PROTECTED]
Please let me know if there's any
created using these primitives?
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Please let me know if there's any further trouble I can give you.
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On 2/22/08, Derek Elkins [EMAIL PROTECTED] wrote:
shift and reset
I was under the impression that reset was a pure function. What side
effects does it have?
--
Taral [EMAIL PROTECTED]
Please let me know if there's any further trouble I can give you.
-- Unknown
On 2/22/08, Taral [EMAIL PROTECTED] wrote:
shift :: Prompt r - ((a - _) - r) - a
(Where _ is either r or forall b. b)
It occurs to me that _ has to be r, otherwise the subcontinuation can escape.
--
Taral [EMAIL PROTECTED]
Please let me know if there's any further trouble I can give you
On 5/24/07, Adrian Hey [EMAIL PROTECTED] wrote:
Taral wrote:
The other syntaxes proposed don't strike me as sufficiently rigorous.
Me neither. It's always been a great source of puzzlement to me why this
very simple and IMO conservative proposal should be so controversial.
Unless someone can
rigorous.
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, this shouldn't matter, however on some platforms an open
file handle can prevent deletion of the file.
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Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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.
--
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You can't prove anything.
-- Gödel's Incompetence Theorem
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On 12/13/06, Alfonso Acosta [EMAIL PROTECTED] wrote:
deactivate :: Maybe(hd - IO ()),
According to the spec, NULL here means no-op. So instead of using
Maybe, just set deactivate = \_ - return () if you see NULL.
--
Taral [EMAIL PROTECTED]
You can't prove anything
On 12/13/06, Taral [EMAIL PROTECTED] wrote:
Second, you don't want the consumer to pick the hd type. If you're
willing to accept extensions (I think you are), make it existential:
data Descriptor = forall hd. Descriptor { ... }
This will ensure that you can't pass the handles from one plugin
On 12/13/06, Alfonso Acosta [EMAIL PROTECTED] wrote:
I don't see what you mean here. I'm not using ForeignPtrs at all.
... you're *writing* a plugin, not using one. Oh. Um... let me think
about that one.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
...
There should be a README or INSTALL file in the original tarball that
explains how to do that. I suspect it is a flag you have to pass to
runhaskell Setup.lhs configure.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
On 12/12/06, Alfonso Acosta [EMAIL PROTECTED] wrote:
So it would be great to be able to use unsafeCoerce.
It would be great -- but Typeable is the only way to get *safe*
typecasts of this type. Otherwise, you may as well run without a
typechecker.
--
Taral [EMAIL PROTECTED]
You can't prove
On 12/11/06, Nia Rium [EMAIL PROTECTED] wrote:
In my humble opinion, in this context, GUI doesn't mean a library to
implement a GUI application. It rather means an interpreter/compiler that
provides graphical interface.
Windows users can use Visual Haskell...
--
Taral [EMAIL PROTECTED]
You
On 12/11/06, Philippa Cowderoy [EMAIL PROTECTED] wrote:
Only those who already have Visual Studio, no?
Yes, that is an unfortunate limitation.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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commands are:
runhaskell Setup.lhs configure
runhaskell Setup.lhs build
runhaskell Setup.lhs install
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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that you're casting Dynamic back to the original type.
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You can't prove anything.
-- Gödel's Incompetence Theorem
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unsafeCoerce a dangerous operation?
Sure it is. The type you gave (MyType Int Char - MyType a b) can
easily crash your program.
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Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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On 12/8/06, Nicolas Frisby [EMAIL PROTECTED] wrote:
I did see that one on the wiki; but it doesn't seem to support the
open intervals (i.e. (-inf, 3)) and I'd really like those.
Oh, it does. See BoundaryAboveAll and BoundaryBelowAll.
--
Taral [EMAIL PROTECTED]
You can't prove anything
)? A possible complication is that I'm hoping to
include open intervals such as (GreaterEqThan 3).
--
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You can't prove anything.
-- Gödel's Incompetence Theorem
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On 12/4/06, Joachim Breitner [EMAIL PROTECTED] wrote:
\g - map (\n a - g a !! n) [1..]
I think that's about as good as it gets.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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On 12/2/06, Huazhi (Hank) Gong [EMAIL PROTECTED] wrote:
myrand :: Int
myrand = randomRIO(1::Int, 100)
rf=[(myrand, myrand) | a - [1..50]]
do
let myrand = randomRIO (1 :: Int, 100)
rf - replicateM 50 (liftM2 (,) myrand myrand)
--
Taral [EMAIL PROTECTED]
You can't prove anything
know where to look or what to search for.
I suggest you check the Functional Graph Library (FGL). It's shipped
as part of GHC.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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Haskell
.
If you're trying to do random access on a list, you should rethink why
you're using a list.
--
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You can't prove anything.
-- Gödel's Incompetence Theorem
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throw in my haskell MIME parser if you want
it. It's not the same as the one that most people use -- but I like it
better. :)
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
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the $ and you'll be fine.
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You can't prove anything.
-- Gödel's Incompetence Theorem
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it? In my mind, the current mode is a
functional one:
Eq :: Eq t = Expr t - Expr t - Expr Bool
And this is perfectly readable. The arrow means that the argument is
an implicit propositional one, but it's still an argument.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's
on a variable in scope. Type signatures have implicit variables.
Also, there's no way for the guard to fall through or anything like
that. It's just not similar enough for me.
--
Taral [EMAIL PROTECTED]
You can't prove anything.
-- Gödel's Incompetence Theorem
ReadP or parsec, they are far superior in general. I think
there was a suggestion of replacing Read with ReadP?
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
-- Edsger Dijkstra
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On 2/6/06, John Hughes [EMAIL PROTECTED] wrote:
The trouble with monad comprehensions was that it became far too easy to
write ambiguous programs, even when you thought you were just working
with lists.
Would the Haskell98-style solution be to add defaulting for Monads?
--
Taral [EMAIL
to be that the left-associative version of $ does not
decrease nesting level so effectively.
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Computer science is no more about computers than astronomy is about
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Haskell
:)
A bit of searching turns up very little, but rolling your own for
simple support is not difficult. OleInitialize, CoCreateInstance,
class IUnknown, class IDispatch, class Variant...
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes
On 1/26/06, Donald Bruce Stewart [EMAIL PROTECTED] wrote:
Something like pattern guards?
f x | Just _ - x = putStrLn something
These subsume pattern guards...
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
-- Edsger Dijkstra
, (t m a - m a) is only possible for very specific
monad transformers...
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
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not just have the function provided in the inner monad,
since the features of the transformer are not available?
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
-- Edsger Dijkstra
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? How does up3 work? MonadIO
exists in Control.Monad.Trans.
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Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
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) - a - c - (b,d)
I have no idea what kind of function would have type (a - b c -
d). Can you give an example?
f :: (a - b a) - c - d - (b c, b d)
f :: (forall a. a - b a) - c - d - (b c, b d)
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
types around it.
--
Taral [EMAIL PROTECTED]
Computer science is no more about computers than astronomy is about
telescopes.
-- Edsger Dijkstra
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