Pasqualino 'Titto' Assini wrote:
I am trying to write an interpreter for a little functional language but I am
finding very problematic to dynamically create a typed representations of the
language terms.
The problem is to write a function that converts between Exp and Term
t as in:
Look at the type of (.).(.).(.)
Dominic.
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Did you look at Ralf Hinze's paper Fun with Phantom Types? Dominic.
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Hello Justin,
Thursday, October 4, 2007, 1:47:00 AM, you wrote:
Which could be stripped off it you wanted:
evilDictatator :: a
evilDictator = runUnsafe $ launchMissiles
just imagine using ByteString library with all these runUnsafe calls
flying around :))) or using immutable arrays -
Hello Maxime,
Thursday, October 4, 2007, 2:55:41 AM, you wrote:
If I write a small C function for doing the finalizer myself, I still
wouldn't get passed the FILE * to close, only the struct foo * pointer
which is of no use.
you can use global assocs list
--
Best regards,
Bulat
On 10/4/07, Pasqualino 'Titto' Assini [EMAIL PROTECTED] wrote:
It does not seem to be possible to define typecheck on EApp in a generic way
and is also not possible to distinguish between the different cases:
You want to pattern-match on types and the easiest way to do it is to
introduce a
On 10/4/07, Dominic Steinitz [EMAIL PROTECTED] wrote:
Look at the type of (.).(.).(.)
Indeed, this generalizes to functions of any arity on the RHS:
Prelude :t (.)
(.) :: (b - c) - (a - b) - a - c
Prelude :t (.).(.)
(.).(.) :: (b - c) - (a - a1 - b) - a - a1 - c
Prelude :t
2007/10/3, Andrew Coppin [EMAIL PROTECTED]:
The entry point OpenThread could not be found in KERNEL32.dll.
Are you using NT 4? Probably GHC 6.6.1 dropped support for it (or
maybe the binary you downloaded was compiled without the support for
it), as this error message means more or less your
On 10/4/07, Jules Bean [EMAIL PROTECTED] wrote:
...and indeed it can't be done, except by the naive brute-force method
of comparing every subtree, possibly optimised by cryptographically
hashing a representation of every subtree, since sharing isn't an
observable property.
At least one Prolog
Thomas Conway wrote:
On 10/4/07, Jules Bean [EMAIL PROTECTED] wrote:
...and indeed it can't be done, except by the naive brute-force method
of comparing every subtree, possibly optimised by cryptographically
hashing a representation of every subtree, since sharing isn't an
observable property.
Stefan O'Rear wrote:
Calling Haskell code from the garbage collector is essentially
impossible to do efficiently and correctly. Don't even try it, your
sanity is not worth saving 3 lines of C coding.
It is a sad thing indeed if that is correct advice.
Jules
Stefan O'Rear wrote:
On Thu, Oct 04, 2007 at 12:55:41AM +0200, Maxime Henrion wrote:
When writing the binding for foo_new(), I need to open a file with
fopen() to pass it the FILE *. Then I get a struct foo * that I can
easily associate the the foo_destroy() finalizer. However, when
On 2007-10-04, Jules Bean [EMAIL PROTECTED] wrote:
Thomas Conway wrote:
On 10/4/07, Jules Bean [EMAIL PROTECTED] wrote:
...and indeed it can't be done, except by the naive brute-force method
of comparing every subtree, possibly optimised by cryptographically
hashing a representation of every
On 2007-10-04, Ronald Guida [EMAIL PROTECTED] wrote:
I need some help with space and time leaks.
I know of two types of space leak. The first type of leak occurs when
a function uses unnecessary stack or heap space.
GHCi sum [1..10^6]
*** Exception: stack overflow
Apparently, the default
Oleg,
thank you so much for taking the time to provide the example code and the
explanation, it really helps.
My mental typechecker seems to diverge on the data EQ a b where Refl :: EQ
a a bit so I am now reading the typing dynamic typing paper, hoping for
further enlightment.
If you
Hello Tomasz,
thank you very much for your advice.
Just a quick question, why using your own Dyn rather than Data.Dynamic?
Regards,
titto
On Thursday 04 October 2007 08:57:11 Tomasz Zielonka wrote:
On 10/4/07, Pasqualino 'Titto' Assini [EMAIL PROTECTED] wrote:
It does not seem to
I just installed the beta release for Ubuntu Gutsy, and I noticed that
gtk2hs (provided by libghc6-gtk-dev) is still at version 0.9.10.5-1ubuntu1.
Worse, it's apparently not installable; when I try I get this message:
libghc6-gtk-dev:
Depends: ghc6 (6.6+) but 6.6.1-2ubuntu2 is to be installed
It was raised at CUFP today that while Python has:
Python is a dynamic object-oriented programming language that can be
used for many kinds of software development. It offers strong
support for integration with other languages and tools, comes with
extensive standard libraries,
Adapting my previous class sample with these ideas, we have:
class Multicompose t1 t2 t3 | t1 t2 - t3 where
infixr 9 +.
(+.)::t1 - t2 - t3
instance Multicompose t1 t2 t3 = Multicompose t1 (a - t2) (a - t3) where
(+.) = (.).(+.)
instance Multicompose (b - c) (a - b) (a -
Ronald Guida wrote:
I need some help with space and time leaks.
I know of two types of space leak. The first type of leak occurs when
a function uses unnecessary stack or heap space.
GHCi sum [1..10^6]
*** Exception: stack overflow
Apparently, the default definition for sum has a space leak.
Salvatore Insalaco wrote:
2007/10/3, Andrew Coppin [EMAIL PROTECTED]:
The entry point OpenThread could not be found in KERNEL32.dll.
Are you using NT 4?
Affirmative. Windows NT 4.0 Service Pack 6a.
Probably GHC 6.6.1 dropped support for it (or
maybe the binary you downloaded was
Ronald Guida wrote:
Now for the hard questions.
1. How do I go about detecting space and time leaks?
2. Once I find a leak, how do I fix it?
3. Are there any programming techniques I can use to avoid leaks?
I'm hard time to believe I'll write something you do not know but
I had similar
UltraSPARC II, Solaris 2.10, gcc 4.0.4 (gccfss),
Haskell GHC 6.6.1 binary release.
Trying to compile a simple file gives me oodles of errors because
ghc is generating something that makes gcc generate lots of these:
sethi %hi(some register),another register
For people unfamiliar with
No, still no idea!
I tried curry f
where f :: (Num a) = (a, a) - a
and it didn't like it.
For some reason I'm finding this a little chalenging.
Thanks, Paul
At 17:03 03/10/2007, you wrote:
On 10/3/07, PR Stanley
mailto:[EMAIL PROTECTED][EMAIL PROTECTED] wrote:
I didn't even know about the curry
On Thu, Oct 04, 2007 at 09:31:56AM -0700, Chad Scherrer wrote:
I just installed the beta release for Ubuntu Gutsy, and I noticed that
gtk2hs (provided by libghc6-gtk-dev) is still at version 0.9.10.5-1ubuntu1.
Worse, it's apparently not installable; when I try I get this message:
On Thu, Oct 04, 2007 at 05:46:09PM +0100, Axel Simon wrote:
Hi,
I'm trying to continuously output data to a file handle while reading
single characters from the user to adjust the speed at which things are
output. I'm interested to get this to work in Hugs on Windows.
I successfully used
Wasn't this the point of the elevator speech thread a few weeks ago?
Saying in 30 seconds why haskell is good and what it can do for you?
On 10/4/07, Don Stewart [EMAIL PROTECTED] wrote:
It was raised at CUFP today that while Python has:
Python is a dynamic object-oriented programming
Here is one trick I have found useful on occasion:
Prelude :t let f = undefined :: (Num a) = (a,a) - a in curry f
let f = undefined :: (Num a) = (a,a) - a in
curry f :: (Num a) = a - a - a
undefined (also called bottom) is an element of every type, so if you
just need
On Thu, Oct 04, 2007 at 05:05:23PM +0100, Pasqualino 'Titto' Assini wrote:
Hello Tomasz,
thank you very much for your advice.
Just a quick question, why using your own Dyn rather than Data.Dynamic?
Well, it's a bit different from Data.Dynamic. You have a guarantee that
(Dyn Term) contains
On Thu, Oct 04, 2007 at 10:36:40AM -0700, Don Stewart wrote:
The Haskell website has the rather strange motivational text:
Haskell is a general purpose, purely functional programming language
featuring static typing, higher order functions, polymorphism, type
classes, and monadic
Yep, its similar to the elevator pitch, but a little shorter, and
mentions why as a programmer this is worth your time.
I'm not sure monadic effects is terribly motivating for someone who's
heard about Haskell, and just wants to get things done faster, and more
reliably -- which is really what
On 10/4/07, Don Stewart [EMAIL PROTECTED] wrote:
It was raised at CUFP today that while Python has:
Python is a dynamic object-oriented programming language that can be
used for many kinds of software development. It offers strong
support for integration with other languages and
catamorphism:
On 10/4/07, Don Stewart [EMAIL PROTECTED] wrote:
It was raised at CUFP today that while Python has:
Python is a dynamic object-oriented programming language that can be
used for many kinds of software development. It offers strong
support for integration with
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