On Sun, Jun 24, 2007 at 10:55:40PM +0200, Hugh Perkins wrote:
> Anyway, the jist of our conversation was that it's not possible to create
> arbitrary datatypes/constructors from strings in Haskell. Can anyone
> deny/confirm?
If you want a function like fromConstr, where the 'a' depends on the
inp
Now I've got a situation I can't figure out how to resolve. I want to
have a set of actions which are executed sequentially, but which, before
I even start to execute the first one, have been inspected for legality
and/or plausibility. Consider this kind of sequence:
do
x <- performActionA
y
hughperkins:
>
>Just noticed that all my responses have been going only to
>Neil, not to the group.
>Anyway, the jist of our conversation was that it's not
>possible to create arbitrary datatypes/constructors from
>strings in Haskell. Can anyone deny/confirm?
Entirely possib
I'll look at those.
Everything's working fine now, thanks for all of your help :)
On 6/24/07, Thomas Schilling <[EMAIL PROTECTED]> wrote:
I found the examples included in the source code very helpful.
http://darcs.haskell.org/packages/GLUT/examples/
I think the RedBook directory contains t
Hugh Perkins wrote:
> Hi,
>
> Trying to write a function to deserialize a haskell type from xml.
>
> deserializeXml :: Data(a) => String -> a
That type signature describes a function that can deliver *anything*
(that is in class Data), whatever you ask from it. From your
description (also the o
I found the examples included in the source code very helpful.
http://darcs.haskell.org/packages/GLUT/examples/
I think the RedBook directory contains the most examples.
If you want to know the modules a package exports you can use, e.g..
$ ghc-pkg describe OpenGL
name: OpenGL
version: 2.2.1
I got the packages imported by using the full names (Graphics.UI.GLUT
and Graphics.Rendering.OpenGL.GL). The compiler doesn't recognize
names like WindowPosition and WindowSize, but I assume that's because
the code is so out of date (this is from the 2001 tutorial). I'll
look in the docs to see
Here it is. Both OpenGL and GLUT are installed:
Cabal-1.1.6.2, GLUT-2.1.1, HUnit-1.1.1, OpenGL-2.2.1,
QuickCheck-1.0.1, Win32-2.1.1, base-2.1.1, cgi-3001.1.1, fgl-5.4.1,
filepath-1.0, (ghc-6.6.1), haskell-src-1.0.1, haskell98-1.0,
html-1.0.1, mtl-1.0.1, network-2.0.1, parsec-2.0, rege
Thanks, Bryan, this is much cleaner than the imperative hack I was
throwing together. And aside from the imports, it even fits the
"couple lines of code" criteria! Wonderful.
I won't be able to try this out until I get back to work, but I'm
wondering whether this will handle a few thousand files.
On 25 jun 2007, at 00.18, Jimmy Miller wrote:
I've installed ghc 6.6.1, but when I try to compile and OGL program
like this:
ghc -package GLUT ogl.hs
I get the error:
Failed to load interface for `GLUT':
Use -v to see a list of the files searched for.
I tried running -v, but it doesn'
I've installed ghc 6.6.1, but when I try to compile and OGL program like this:
ghc -package GLUT ogl.hs
I get the error:
Failed to load interface for `GLUT':
Use -v to see a list of the files searched for.
I tried running -v, but it doesn't tell me anything useful.
On 6/24/07, Thomas Schi
Oleg,
Once again, many thanks. This is great info. BTW, i realized that my
approach has an underlying process algebraic formulation. Roughly speaking,
you can think of the mutable collection as a tuple space in which the names
of the tuple space are the mutable locations in the collection. Update
Yes, or better:
gshow' :: Data a => a -> String
gshow' t = fromMaybe (showConstr(toConstr t)) (cast t)
(which gets rid of the parentheses around numbers).
Still doesnt get a deserialize though ;-)
On 6/24/07, Andrea Vezzosi <[EMAIL PROTECTED]> wrote:
As a side note i'd like to point out that
Just noticed that all my responses have been going only to Neil, not to the
group.
Anyway, the jist of our conversation was that it's not possible to create
arbitrary datatypes/constructors from strings in Haskell. Can anyone
deny/confirm?
___
Haskell
Yes, the OpenGL website seems unmaintained. I presume the easiest
way to set it all up is to use the installer from
http://www.haskell.org/ghc/download_ghc_661.html#windows
From the size of it it seems to include all the extra packages.
/ Thomas
On 24 jun 2007, at 21.50, Jimmy Miller wrote
I added Cygwin to my path so sh can be found, but now configure tells
me "c compiler cannot create executables"
On 6/24/07, Jimmy Miller <[EMAIL PROTECTED]> wrote:
I already installed Cygwin; I'll go over the INSTALL file and make
sure I have all the required packages.
And there was an HOpenGL
I already installed Cygwin; I'll go over the INSTALL file and make
sure I have all the required packages.
And there was an HOpenGL tutorial from 2001 that said OpenGL would
eventually be packaged with ghc, but I tried -package OpenGL and that
didn't work, and I'm not sure where else I could downl
On 24 jun 2007, at 19.53, Jimmy Miller wrote:
Thanks, didn't know that.
Here's the configure output:
Configuring OpenGL-2.1...
configure: C:\ghc\ghc-6.6\bin\ghc-pkg.exe
configure: Dependency base-any: using base-2.0
configure: Using install prefix: C:\Program Files
configure: Binaries installe
Thanks, didn't know that.
Here's the configure output:
Configuring OpenGL-2.1...
configure: C:\ghc\ghc-6.6\bin\ghc-pkg.exe
configure: Dependency base-any: using base-2.0
configure: Using install prefix: C:\Program Files
configure: Binaries installed in: C:\Program Files\Haskell\bin
configure: Lib
Hi Daniil,
By "embedded" DSL, we usually mean identifying meta-language (Haskell)
expressions with object language (DSL) expressions, rather than having an
"Exp" data type. Then you just use meta-language variables as
object-language variables. The new data types you introduce are then
domain-o
Chad Scherrer wrote:
What got me thinking about this is I'd like to be able to do something
like this in just a couple lines of code:
gunzip -c ./2*/*.z
... and feed the result into a giant lazy ByteString.
Using my FileManip library, you'd do that like this.
import Codec.Compression.GZip
i
As a side note i'd like to point out that introspectData has a problem with
constructors containing Strings because show (x::String) /= x:
data Foo = Foo { bar :: String } deriving (Typeable,Data)
introspectData (Foo "quux") --> [("bar","\"quux\"")]
Those extras \" don't look very nice in the x
No, ffi is no extra package. It would be helpful if you posted you
configure output though.
BTW, please CC the list when replying. The easiest way should be to
use the "reply all" feature of your mail client.
Thanks,
Thomas
On 24 jun 2007, at 15.24, Jimmy Miller wrote:
That's all I k
also try replacing that (foldl' intersect') with (foldr (flip intersect'))!
OK, next question: Given that I'm using all the results from
intersect', why is the lazy version better than the strict one? Is ghc
managing to do some loop fusion?
haskell tends to prefer foldr where mls prefer foldl,
True enough, in a sense, a dynamically typed language is like a
statically typed language with only one type (probably several by
distinguishing function types) and many incomplete pattern matches.
So, you can embed a dynamically typed language into a strongly typed
language without loosing stati
Hi
mkConstr :: String -> Constr
parseData :: (Data a) => String -> a
fromConstr, plus a bit of work to create the constructor.
http://www.haskell.org/hoogle/?q=fromConstr
Thanks
Neil
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://ww
Trying to create a datatype/constructor given just its constructor as a
string, something like:
mkConstr :: String -> Constr
parseData :: (Data a) => String -> a
***without knowing in advance anything about the datatype apart from the
string contents***
So, not something like:
parseData "Just
Hi,
Trying to write a function to deserialize a haskell type from xml.
Ideally this wont need a third "DTD" file, ie it will work something like
XmlSerializer.Deserialize from C#:
deserializeXml :: Data(a) => String -> a
serializeXml :: Data(a) => a -> String
Writing serializeXml is pretty eas
That looks like a missing C macro definition. It should probably
expand to either stdcall or ccall. A bit more information would be
helpful.
On 24 jun 2007, at 13.11, Jimmy Miller wrote:
I'm trying to install HOpenGL 2.1, with ghc 6.6 on Windows XP.
runghc Setup.hs configure seems to wor
Neil Mitchell wrote:
>> 1) The programmer has to detail in some form the proof that his program
>> terminates. Arguably, he ought to do so anyway but he doesn't need to
>> write his proof in a way that can be checked by a dumb computer. Take
>> for example
>>
>> minimum = head . sort
>
> minimum
Hi
1) The programmer has to detail in some form the proof that his program
terminates. Arguably, he ought to do so anyway but he doesn't need to
write his proof in a way that can be checked by a dumb computer. Take
for example
minimum = head . sort
minimum [1..] gives _|_ non-termination
mi
I'm trying to install HOpenGL 2.1, with ghc 6.6 on Windows XP.
runghc Setup.hs configure seems to work fine. It gives messages about
things missing, like sh, but there are no errors.
When I run runghc Setup.hs build, I get the following error:
[ 4 of 81] Compiling Graphics.Rendering.OpenGL.GL.E
Dave Bayer wrote:
> I've enjoyed the recent typing discussions here. On one hand, there's
> little difference between using dynamic typing, and writing incomplete
> patterns in a strongly typed language. On the other hand, how is an
> incomplete pattern any different from code that potentially divi
On Sat, 23 Jun 2007, David Roundy wrote:
> > I refuse to drink the Kool-Aid and recite precisely what I'm told a
> > type is in June, 2007; I'm hoping that types will evolve by the time
> > I die. For types to evolves, we need to step back a few feet and
> > think more loosely what a type really
andrewcoppin:
> Bulat Ziganshin wrote:
> >Hello Andrew,
> >
> >
> >definitive reading: "Tackling the awkward squad: monadic input/output,
> >concurrency, exceptions, and foreign-language calls in Haskell"
> >http://research.microsoft.com/Users/simonpj/papers/marktoberdorf/marktoberdorf.ps.gz
> >
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