TFM2009
2nd Int. FME Conference on Teaching Formal Methods
Widening Access to Formal Methods
Friday, November 6th 2009, co-located with
FM2009 : 16th International Symposium
Hi,
I regularly (almost daily) have problems reaching both community and
code.haskell.org, getting 500 server error messages. I've decided to
make all my Haskell code available on community, which means that when
it goes down, I can't access my repos - which is not great.
Is there a reason for
Hi
Questions of parametricity in dependent types are made more
complex by the way in which the Pi-type
(x : S) - T
corresponds to universal quantification. It's good to think
of this type as a very large product, tupling up individual
T's for each possible x you can distinguish by
Michael P Mossey wrote:
I've got one of those algorithms which threatens to march off the
right edge (in the words of Goerzen et al). I need something like a
State or Maybe monad, but this is inside the IO monad. So I presume I
need StateT or MaybeT. However, I'm still (slowly) learning about
Hi,
I regularly (almost daily) have problems reaching both community and
code.haskell.org, getting 500 server error messages. I've decided to
make all my Haskell code available on community, which means that when
it goes down, I can't access my repos - which is not great.
Is there a reason for
On 13/05/2009 19:53, Donnie Jones wrote:
Hello Dan,
Best place to ask is glasgow-haskell-us...@haskell.org since that is
the GHC users list.
I have CC'd your email to the GHC user list.
Cheers.
--
Donnie Jones
On Wed, May 13, 2009 at 1:35 PM, Dandanielkc...@gmail.com wrote:
Hi,
Not sure if
I've got one of those algorithms which threatens to march off the right edge (in the words of
Goerzen et al). I need something like a State or Maybe monad, but this is inside the IO monad. So
I presume I need StateT or MaybeT. However, I'm still (slowly) learning about monads from first
Vasili I. Galchin schrieb:
Hello,
I am confused between Haskell as delineated in the Haskell Report
VS ghc pragmas which extend Haskell beyond the Haskell Report. I am
sure I am not the first to ask. Caveat: on my part, I am not against
innovation/extensions, but I don't like to see
On 13/05/2009 13:07, Duncan Coutts wrote:
On Wed, 2009-05-13 at 15:37 +0400, Bulat Ziganshin wrote:
Hello Duncan,
Wednesday, May 13, 2009, 3:33:13 PM, you wrote:
I think it should remain deprecated and we should work on the
replacement so that TH can switch its dependency.
TH isn't
Hello,
For a while now, I've been trying to come up with a fast Haskell-only
function which implements Euclidean distance in n-dimensional space.
So far, I've been disappointed by the performance of my best effort
in Haskell, compared to C. I'm hoping some of the Haskell experts
and/or
My current best try uses the uvector package, has two 'vectors' of type
(UArr Double) as input, and relies on the sumU and zipWithU functions
which use streaming to compute the result:
dist_fast :: UArr Double - UArr Double - Double
dist_fast p1 p2 = sumDs `seq` sqrt sumDs
where
kenneth.hoste:
Hello,
For a while now, I've been trying to come up with a fast Haskell-only
function which implements Euclidean distance in n-dimensional space.
So far, I've been disappointed by the performance of my best effort
in Haskell, compared to C. I'm hoping some of the Haskell
Hi all,
I'm trying to express a constraint using a data structure.
Let's say I'd want to express a mapping of a to b, c to b, d to b and
e to f.
A mapping can also be from a to a, b to b and so on.
The constraint is that one cannot map a to b if b was already mapped
to let's say c.
I'd
Hi all,
I'm giving a presentation to an IEEE group on Embedded DSL's and Haskell at
the end of June. I need a 3 to 4 slide introduction to Haskell. What
suggestions does the community have? Is such a short intro possible?
It just needs to introduce the basics so I can show some code without
Just please don't show them qsort and fibonacci!
2009/5/18 John Van Enk vane...@gmail.com:
Hi all,
I'm giving a presentation to an IEEE group on Embedded DSL's and Haskell at
the end of June. I need a 3 to 4 slide introduction to Haskell. What
suggestions does the community have? Is such a
vanenkj:
Hi all,
I'm giving a presentation to an IEEE group on Embedded DSL's and Haskell at
the
end of June. I need a 3 to 4 slide introduction to Haskell. What suggestions
does the community have? Is such a short intro possible?
It just needs to introduce the basics so I can show
Hi Don (and cafe),
Given the example you just posted, is there a simple way to generate the
de-sugared haskell / core / STG / labelled-assembly versions of a piece of
haskell code? For instance, how did you generate the content below? I guess
this is the core language version?
I'm a C/C++
That's the output of ghc -ddump-simpl.
2009/5/18 Sam Martin sam.mar...@geomerics.com:
Hi Don (and cafe),
Given the example you just posted, is there a simple way to generate the
de-sugared haskell / core / STG / labelled-assembly versions of a piece of
haskell code? For instance, how did you
Yes, I use the ghc-core tool:
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/ghc-core
sam.martin:
Hi Don (and cafe),
Given the example you just posted, is there a simple way to generate the
de-sugared haskell / core / STG / labelled-assembly versions of a piece of
haskell
Brilliant! Thanks.
-Original Message-
From: Don Stewart [mailto:d...@galois.com]
Sent: Mon 18/05/2009 16:21
To: Sam Martin
Cc: Kenneth Hoste; Haskell Cafe mailing list
Subject: Re: de-sugared code? (branch from: fast Eucl. dist. - Haskell vs C)
Yes, I use the ghc-core tool:
dist_fast :: UArr Double - UArr Double - Double
dist_fast p1 p2 = sumDs `seq` sqrt sumDs
where
sumDs = sumU ds
ds= zipWithU euclidean p1 p2
euclidean x y = d*d
where
Use an incredibly small font.
On Mon, May 18, 2009 at 8:16 AM, John Van Enk vane...@gmail.com wrote:
Hi all,
I'm giving a presentation to an IEEE group on Embedded DSL's and Haskell at
the end of June. I need a 3 to 4 slide introduction to Haskell. What
suggestions does the community have?
claus.reinke:
dist_fast :: UArr Double - UArr Double - Double
dist_fast p1 p2 = sumDs `seq` sqrt sumDs
where
sumDs = sumU ds
ds= zipWithU euclidean p1 p2
euclidean x y = d*d
where
Use an incredibly small font AND Haskell FRP [1] to zoom and enlarge
the font as you move your mouse over the text. ;)
1. http://en.wikipedia.org/wiki/Functional_reactive_programming
--
Donnie Jones
On Mon, May 18, 2009 at 10:56 AM, David Leimbach leim...@gmail.com wrote:
Use an incredibly
On 16:25 Mon 18 May , Gü?nther Schmidt wrote:
Hi all,
I'm trying to express a constraint using a data structure.
Let's say I'd want to express a mapping of a to b, c to b, d to b and e
to f.
A mapping can also be from a to a, b to b and so on.
The constraint is that one cannot map a
While an incredibly small font is a clever option, a more serious
suggestion may be as follows.
3-4 slides imply 3-4 topics, so the question is what are the 3-4 biggest
topics in haskell? I would think they would be:
* Purity/Referential Transparency
* Lazy Evaluation
* Strong Typing + Type
Thanks Joe,
Your assumption is correct--the whole presentation will be longer. I wanted
to use 3 or 4 slides to introduce the language and the balance for the
interesting stuff. :P
/jve
PS to Joe: I will not forget to reply to all. I will not forget to reply to
all. I will not forget to reply
Don't forget to include higher-order functions in one of those important
points.
On Mon, May 18, 2009 at 12:36 PM, John Van Enk vane...@gmail.com wrote:
Thanks Joe,
Your assumption is correct--the whole presentation will be longer. I wanted
to use 3 or 4 slides to introduce the language and
Actually, I don't think it's a good idea to introduce monads on one of
the 3-4 slides. While it *is* a core concept, it's not one of the
advertising bullet points; and 1 slide is not enough to show what
*use* monads are, let alone what they actually *are*.
I'd probably suggest you to show
Am Sonntag, 17. Mai 2009 15:08:29 schrieb Don Stewart:
Sven.Panne:
[...]
I think most problems can be fixed in a rather pragmatic way by adding a
few functions to the binary package:
[...]
Patches are welcome.
Attached. A few remarks:
* This is only a quick and mildly tested
On Mon, May 18, 2009 at 3:08 AM, Neil Brown nc...@kent.ac.uk wrote:
With ErrorT you can use throwError when you want to break out of the
block and give back an error, which seems to fit what you were doing.
Of course, now that you are using throwError, you can remove a lot of
the extra
I've got one of those algorithms which threatens to march off the right edge (in the words of
Goerzen et al). I need something like a State or Maybe monad, but this is inside the IO monad.
So I presume I need StateT or MaybeT. However, I'm still (sdlowly) learning about monads from
first
Tons of relevant changes. Almost too many to count...
Buster:
- Fixed performance and bugs in buster,
- split out buster, buster-network, and buster-gtk to make it easier
to only build components of the system.
- Added new functions in buster for selection and debugging.
- Added behaviours in
Excerpts from Jason Dusek's message of Sun May 17 15:45:25 +0200 2009:
From the documentation:
LI could be a strict monad and a strict applicative functor.
However it is not a lazy monad nor a lazy applicative
functor as required Haskell. Hopefully it is a lazy
(pointed)
Well, since the topic was EDSLs, and those generally involve monads (at
least from what I've seen), it might be wise to touch on them. However,
perhaps the fourth slide would just be a catchall? HOFs, some STM/Monad
stuff, etc? The topics I suggested just seem to me to be the 4 core
concepts
On 18 May 2009, at 20:29, Joe Fredette wrote:
While an incredibly small font is a clever option, a more serious
suggestion may be as follows.
3-4 slides imply 3-4 topics, so the question is what are the 3-4
biggest topics in haskell? I would think they would be:
* Purity/Referential
jfredett:
While an incredibly small font is a clever option, a more serious
suggestion may be as follows.
3-4 slides imply 3-4 topics, so the question is what are the 3-4 biggest
topics in haskell? I would think they would be:
* Purity/Referential Transparency
* Lazy Evaluation
*
ekirpichov:
Actually, I don't think it's a good idea to introduce monads on one of
the 3-4 slides. While it *is* a core concept, it's not one of the
advertising bullet points; and 1 slide is not enough to show what
*use* monads are, let alone what they actually *are*.
I'd probably suggest
On Mon, May 18, 2009 at 2:06 PM, Don Stewart d...@galois.com wrote:
Exactly: focus on what the user wants to do (e.g. write multicore code,
write safe code, write code quickly), not how that is achieved:
bounded parametric polymorphism or monads
Parametric polymorphism is a big win, and
adam.turoff:
On Mon, May 18, 2009 at 2:06 PM, Don Stewart d...@galois.com wrote:
Exactly: focus on what the user wants to do (e.g. write multicore code,
write safe code, write code quickly), not how that is achieved:
bounded parametric polymorphism or monads
Parametric polymorphism is a
The main bullet point is missing: Correctness.
How could we have forgotten quickcheck?
quickCheck (\xs - sort (sort xs) == sort xs)
OK, 100 tests passed.
2009/5/18 Don Stewart d...@galois.com:
adam.turoff:
On Mon, May 18, 2009 at 2:06 PM, Don Stewart d...@galois.com wrote:
Exactly: focus
Once I actually add a 'dist_fast_inline_caller', that indirection
disappears in the inlined code, just as it does for dist_fast itself.
dist_fast_inlined_caller :: UArr Double - UArr Double - Bool
dist_fast_inlined_caller p1 p2 = dist_fast_inlined p1 p2 2
However, in the simpl output
claus.reinke:
Once I actually add a 'dist_fast_inline_caller', that indirection
disappears in the inlined code, just as it does for dist_fast itself.
dist_fast_inlined_caller :: UArr Double - UArr Double - Bool
dist_fast_inlined_caller p1 p2 = dist_fast_inlined p1 p2 2
However, in
As I said, I don't get the fusion if I just add the function above to the
original Dist.hs, export it and compile the module with '-c -O2
-ddump-simpl':
I can't reproduce this.
Interesting. I'm using ghc 6.11.20090320 (windows), uvector-0.1.0.3.
I attach the modified Dist.hs and its simpl
On Mon, May 18, 2009 at 11:33 AM, Eugene Kirpichov ekirpic...@gmail.com wrote:
The main bullet point is missing: Correctness.
How could we have forgotten quickcheck?
quickCheck (\xs - sort (sort xs) == sort xs)
OK, 100 tests passed.
I like this, but given that you have a whole slide, I
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
Hello,
Do newSTArray, readSTArray, writeSTArray, etc. belong to an old
deprecated Hugs library/module? If so, what is the Haskell 98 replacement?
Thanks, Vasili
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I've been playing around with The Little MLer (pg. 95, 96) to try to improve
my understanding of types.
I can ask ML:
- ints(0);
val it = Link (1,fn) : chain
-
and Haskell:
*Main :t ints 0
ints 0 :: Chain
*Main ints 0
interactive:1:0:
No instance for (Show Chain)
arising from a
I've been playing around with The Little MLer (pg. 95, 96) to try to improve
my understanding of types.
I can ask ML:
- ints(0);
val it = Link (1,fn) : chain
-
and Haskell:
*Main :t ints 0
ints 0 :: Chain
*Main ints 0
interactive:1:0:
No instance for (Show Chain)
arising from a
On May 18, 2009, at 18:34 , Vasili I. Galchin wrote:
Do newSTArray, readSTArray, writeSTArray, etc. belong to an
old deprecated Hugs library/module? If so, what is the Haskell 98
replacement?
My understanding is they should be in the provided STArray module.
--
brandon s. allbery
On May 18, 2009, at 21:19 , michael rice wrote:
*Main :t ints 0
ints 0 :: Chain
*Main ints 0
interactive:1:0:
No instance for (Show Chain)
In general, you want to append
deriving Show
to your types. You may also want to be able to input them in ghci, so
instead say
Unfortunately, you can't derive Show on Chain as defined, because it
contains a function:
data Chain = Link Int (Int - Chain)
You can write this:
instance Show Chain where
show (Link n _) = Link ++ show n ++ fn
Or you can make a dummy Show instance for functions:
instance Show (a -
On Mon, May 18, 2009 at 10:02 PM, Ryan Ingram ryani.s...@gmail.com wrote:
Unfortunately, you can't derive Show on Chain as defined, because it
contains a function:
Sure you can. I just tried the following, and it compiled without complaints.
import Text.Show.Functions
data Chain = Link Int
On Mon, May 18, 2009 at 6:34 PM, Vasili I. Galchin vigalc...@gmail.com wrote:
Hello,
Do newSTArray, readSTArray, writeSTArray, etc. belong to an old
deprecated Hugs library/module? If so, what is the Haskell 98 replacement?
I don't know about Haskell 98, but I think the modern solution
_
Insert movie times and more without leaving Hotmail®.
http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tutorial_QuickAdd1_052009___
Haskell-Cafe mailing list
thank to all respondents!
Vasili
On Mon, May 18, 2009 at 9:41 PM, David Menendez d...@zednenem.com wrote:
On Mon, May 18, 2009 at 6:34 PM, Vasili I. Galchin vigalc...@gmail.com
wrote:
Hello,
Do newSTArray, readSTArray, writeSTArray, etc. belong to an old
deprecated Hugs
Hello,
I know that some Lawvere papers are available on TAC, but is there a
list of all Lawvere papers online and where?
Kind regards,
Vasili
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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 a - (a - LI b) - LI b
This is a common problem with trying to use
Hi, friends
the following function works well
rollDice n = getStdRandom (randomR (1,n)) :: IO Int
now i want to use /dev/random to produce better random number, but it doesnot
work
rollDice_t n = do
hd - openFile /dev/random ReadMode
v - B.hGet hd 1
return (v `mod` n) + 1
No
On May 19, 2009, at 01:07 , z_axis wrote:
rollDice_t n = do
hd - openFile /dev/random ReadMode
v - B.hGet hd 1
return (v `mod` n) + 1
No instance for (Integral B.ByteString)
You can't just read a binary string and have it interpreted as a
number; you want to use Data.Binary to
On Mon, May 18, 2009 at 10:13 PM, Brandon S. Allbery KF8NH
allb...@ece.cmu.edu wrote:
On May 19, 2009, at 01:07 , z_axis wrote:
rollDice_t n = do
hd - openFile /dev/random ReadMode
v - B.hGet hd 1
return (v `mod` n) + 1
No instance for (Integral B.ByteString)
You can't just
On Mon, May 18, 2009 at 10:13 PM, Brandon S. Allbery KF8NH
allb...@ece.cmu.edu wrote:
On May 19, 2009, at 01:07 , z_axis wrote:
rollDice_t n = do
hd - openFile /dev/random ReadMode
v - B.hGet hd 1
return (v `mod` n) + 1
No instance for (Integral B.ByteString)
You can't just
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