On Thu, 2006-08-24 at 20:53 +0200, Andrea Rossato wrote:
> Hello!
>
> I' m new to Haskell and try to find my way through types and monads.
> I tried the yet Another Haskell Tutorial, very useful for types, but
> almost unreadable for monads (that's my perspective!).
> Then I discovered that wonder
Hello Gregory,
Friday, August 25, 2006, 3:08:09 AM, you wrote:
> Some performance data: using unsafeIOToST to write log messages
> directly to the output, the simulation does 10^7 state updates in
> about 45 seconds
> on my 1.5 GHz ppc G4. Using LogT, with a list of strings as the monoid,
> i
Hi,
I am trying out Alex. I copied the calculator specification file from Alex's
official document and changed the wrapper type from "basic" to "monad".
However, after I generated the ".hs" file from the lexical specification and
compiled the ".hs" file, I got the message "Variable not in scope
Il Thu, Aug 24, 2006 at 08:02:38PM +0100, Neil Mitchell ebbe a scrivere:
> Just shove it on the wiki regardless. If its useless then no one will
> read it. If its a bit unreadable, then people will fix it. If its
> useful the world will benefit. Any outcome is a good outcome!
Ok: I've put it on th
On Aug 25, 2006, at 6:27 AM, Xiong Yingfei wrote:
Hi,
I am trying out Alex. I copied the calculator specification file
from Alex's official document and changed the wrapper type from
"basic" to "monad". However, after I generated the ".hs" file from
the lexical specification and compiled
On 25 aug 2006, at 05.02, Jason Dagit wrote:
Hello,
I recently became the owner a USB gadget that tracks movement via GPS
and also tracks heart rate (it's a training device for athletes).
This device comes with software that is windows only and...doesn't
like up to it's potential (to put it pol
Hi Bulat,
On Aug 25, 2006, at 3:36 AM, Bulat Ziganshin wrote:
Hello Gregory,
Friday, August 25, 2006, 3:08:09 AM, you wrote:
Some performance data: using unsafeIOToST to write log messages
directly to the output, the simulation does 10^7 state updates in
about 45 seconds
on my 1.5 GHz ppc
Robert Dockins wrote:
On Aug 25, 2006, at 6:27 AM, Xiong Yingfei wrote:
Hi,
I am trying out Alex. I copied the calculator specification file from
Alex's official document and changed the wrapper type from "basic" to
"monad". However, after I generated the ".hs" file from the lexical
specif
Bjorn Bringert wrote:
For cross-platform USB drivers, you may want to have a look at libusb
[1]. I have only used it under Linux, but it seems to support Linux,
*BSD and OS X. There also seems to be a win32 port [2]. A Haskell
binding to libusb would be very welcome.
I'm just wondering, would
On 8/25/06, Bjorn Bringert <[EMAIL PROTECTED]> wrote:
On 25 aug 2006, at 05.02, Jason Dagit wrote:
> Hello,
>
> I recently became the owner a USB gadget that tracks movement via GPS
> and also tracks heart rate (it's a training device for athletes).
> This device comes with software that is wind
Hello,
When I compile my program without
profiling:
bash-3.1$ ghc --make -auto-all
-prof -O -o analysis analysis.hs
Chasing modules from:
analysis.hs
Compiling Main
( analysis.hs, analysis.o )
Linking ...
everything works fine.
However when I compile with profilin
Hello!
I cannot understand this piece of code:
type Z = Int
type T a = Z -> (a, Z)
Hi
type Z = Int
Here you can replace all occurances of Z with Int, and its exactly the
same program.
newtype T1 a = T1 (Z -> (a,Z))
newtype T1 a is the same as
data T1 a
why mkT is a type constructor and mkT1 seems not to be?
In what way is mkT a type constructor? In this program only T1
On 25/08/06, Jeff Polakow <[EMAIL PROTECTED]> wrote:
However when I compile with profiling:
bash-3.1$ ghc --make -auto-all -prof -O -o analysis analysis.hs
Chasing modules from: analysis.hs
Could not find module `Data.ByteString.Lazy.Char8':
use -v to see a list of the files se
Il Fri, Aug 25, 2006 at 07:52:35PM +0100, Neil Mitchell ebbe a scrivere:
> >why mkT is a type constructor and mkT1 seems not to be?
> In what way is mkT a type constructor? In this program only T1 is a
> type constructor, as far as I can see.
read my sentence as
"why T is a type constructor and T1
Hi
(2,5) whose type is "T a"
No, try expanding the type synonyms:
mkT :: a -> T a
mkT :: a -> Z -> (a, Z)
mkT :: a -> Int -> (a, Int)
The type of (2,5) is (a, Int), or in this specific case (Int, Int).
they return the same stuff with different types. Onle myT will return a
type of type "T
Andrea Rossato wrote:
Hello!
I cannot understand this piece of code:
type Z = Int
type T a = Z -> (a, Z)
newtype T1 a = T1 (Z -> (a,Z))
mkT :: a -> T a
mkT a = \x -> (a, x)
Hi Andrea,
The definition of mkT above is identical to just writing:
mkT :: a -> (Z -> (a,Z))
which in turn is id
Il Fri, Aug 25, 2006 at 08:35:01PM +0100, Brian Hulley ebbe a scrivere:
> It is maybe easier to just think of a newtype decl as being the same as a
> data decl except for the fact that you can only have one constructor on the
> rhs whereas a data decl allows multiple constructors, and a type decl
hi,
the Haskell Report 10.4 says that
"The result of show is readable by read if all component types are readable"
however if I define a type like
data T = A | T `And` T deriving (Read, Show)
then
*Main> show $ A `And` A
"A And A"
*Main> (read "A And A") :: T
*** Exception: Prelude.read
Am Freitag, 25. August 2006 23:55 schrieb Andrea Rossato:
> Il Fri, Aug 25, 2006 at 08:35:01PM +0100, Brian Hulley ebbe a scrivere:
> > It is maybe easier to just think of a newtype decl as being the same as a
> > data decl except for the fact that you can only have one constructor on
> > the rhs w
On Aug 25, 2006, at 6:50 PM, Misha Aizatulin wrote:
hi,
the Haskell Report 10.4 says that
"The result of show is readable by read if all component types are
readable"
however if I define a type like
data T = A | T `And` T deriving (Read, Show)
then
*Main> show $ A `And` A
"A And
Hi
*Main> show $ A `And` A
"A And A"
For me, using GHCi 6.4.2 + Windows, I get:
"A `And` A"
Which all works perfectly.
For reference, Hugs writes out "And A A", and then parses it back again.
Hugs cannot cope with the "A `And` A" form with read, and GHC can't
cope with "And A A".
Thanks
N
Il Sat, Aug 26, 2006 at 01:27:38AM +0200, Daniel Fischer ebbe a scrivere:
> Because T a is a function type, namely Int -> (a,Int), so
...
> iHowever, neither T1 a nor T2 a is a function type, a value of type
> T1 a is a function _wrapped by the data (or value) constructor T1_ (the same
> applies
Am Samstag, 26. August 2006 00:50 schrieb Misha Aizatulin:
> hi,
>
> the Haskell Report 10.4 says that
>
> "The result of show is readable by read if all component types are
> readable"
>
> however if I define a type like
>
> data T = A | T `And` T deriving (Read, Show)
>
> then
>
> *Main> sh
Il Sat, Aug 26, 2006 at 01:27:38AM +0200, Daniel Fischer ebbe a scrivere:
> unT1 :: T1 a -> T a
> unT1 (T1 f) = f
>
> makeT1 a b = unT1 (mkT1 a) b
>
> will work fine.
*Prelude> :t makeT1
makeT1 :: a -> Int -> (a, Int)
*Prelude>
not that fine, though. Quite useless.
try chancing to:
> unT1 ::
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