e forum outside Haskell as well), I knew many people (my
former students for example), who read only the -café list...
Live long and prosper.
Jerzy Karczmarczuk
[France.]
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?
Jerzy Karczmarczuk
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exquisite continuations and will use
them. Instead of fighting against exceptions it might be more fruitful
to make them more robust, powerful, parametrable and sexy.
Jerzy Karczmarczuk
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to jump.
This is as simple as that.
Jerzy Karczmarczuk
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Kim-Ee Yeoh comments my reading suggestion:
Indiscrete Thoughts by Gian-Carlo Rota, published by Birkhäuser
in 1997. Available on the Web. [I forgot where]
I'm rather fond of Rota's two volumes of musings. For the purpose of
furthering the quality of philosophizing, would it not be
that for Rota the term
should is very important, even if it impossible to define...)
Many thanks to Olivier Danvy, who recommended me this book!
Jerzy Karczmarczuk
Caen, France.
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add to all this:
getLine == getLine
etc.?
Good luck!
I suspect that you would have to establish also the equality relation
between functions and between infinite streams.
And you would end as Giordano Bruno and Jeanne d'Arc. But for different
reasons.
Jerzy Karczmarczuk
I am sorry for having mixed-up arguments (but who throws the first
stone?...)
Jerzy seemed to suggest that the impurity of IO was somehow related to it
not supporting very many operations.
No, not really. I added
First, it is not true that you can do with, say, (printStr Ho! )
whatever you
with the object, it won't fire a
magic process. As Richard, I do not claim that this is right, but it
surely facilitated my teaching of Haskell. My students have already more
than enough of my /philosophie de pacotille/...
Jerzy Karczmarczuk
notion, inherited from pure functions to something
which belongs to two different worlds.
Jerzy Karczmarczuk
PS. I believe that some impure remarks about the familiarity of X or Y
with English do not belong to this forum.
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reached finally the Noble Domain
of Philosophy. I mean, instead of discussing concepts, people begin to
discuss names.
And since for some, even IO () is a pure value, I suspect that the
next round will rekindle the discussion on the word pure...
Jerzy Karczmarczuk
Le 06/08/2013 11:01, J. Stutterheim a écrit :
... So in reply to Jerzy, I do want to encourage the discussion in the Noble Domain
of Philosophy and I also want to repeat that I am not proposing to change Haskell
or Haskell libraries
Jurriën, I taught Haskell for several years. I saw the
of purity for them. No side
effects? Sure, if you don't do anything with it. Even the most horrible
Devil is pure. Unless you call it...
Jerzy Karczmarczuk
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Le 09/07/2013 13:53, Tom Nielsen a écrit :
Almost everything else -- optimal decisions, categorisation, (...) --
becomes trivial.
Optimal decisions trivial?
Interesting... And not so frequent...
Jerzy Karczmarczuk
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, and the rest of the community, that
Haskell will always spiritually remain the same clean,
consistent programming language as it is now!
Yes.
Dear Mom, dear Dad! Promise me that you will never die...
I wish that for all of you.
Jerzy Karczmarczuk
almost-syntax error was clear...
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it might help to know what do you need it for...
The best
Jerzy Karczmarczuk
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is
simply wrong.
==
In general, even correcting all, you might have reasonable results in
some trivial cases, but in general the extrapolating Euler schema is
unstable, produces growing errors (e. g. in the oscillating case).
Jerzy Karczmarczuk
Le 17/04/2013 01:48, Jerzy Karczmarczuk a écrit :
With constant acceleration v=v0+a*Dt = 1.01, not 1.05
Gosh, trivial errors seem to be contagious. Of course I meant 1.1, not
1.01. Sorry. JK
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.
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, the loss of time might be considerable.
Roman: - Christopher Howard seems to be very far from publishing papers;
he asks us whether he should complete his B.S. In this context,
recommending Open Source seems a bit premature.
Jerzy Karczmarczuk
Le 29/08/2012 23:55, Henk-Jan van Tuyl a écrit :
In conclusion: repeating the same thing could give different results.
Certainly!
My favourite example is : sex.
Jerzy Karczmarczuk
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believe that this solution is known for years...
Jerzy Karczmarczuk
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+ loops.
Jerzy Karczmarczuk
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Le 26/03/2012 02:41, Chris Smith a écrit :
Of course there are rings for which it's possible to represent the
elements as lists. Nevertheless, there is definitely not one that
defines (+) = zipWith (+), as did the one I was responding to.
What?
The additive structure does not define a ring.
Le 26/03/2012 16:31, Chris Smith a écrit :
If you were
asking about why there is no ring on [a] that defines (+) = zipWith
(+), then here's why. By that definition, you have [1,2,3] + [4,5] =
[5,7]. But also [1,2,42] + [4,5] = [5,7]. Addition by [4,5] is not
one-to-one, so [4,5] cannot be
-XFlexibleInstances .
(Then you might have some other small problems, but nobody is perfect).
Jerzy Karczmarczuk
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disturb my sleep.
You know, there is no good way to organise a society where everybody
obeys the Law. This is no argument against the organisation of a Society...
Thank you.
Jerzy Karczmarczuk
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the exponential [using the standard name]
of a power series, unless you declare this series, which may be a list
of rational coefficients, a Floating.
Thank you.
Jerzy Karczmarczuk
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* REASONS??
Thank you.
Jerzy Karczmarczuk
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to share the same name,
because *the type system* prevents that a computing block refers to
both. Either the old, or the new.
This is my philosophy. If somebody disagrees, that's alright.
Jerzy Karczmarczuk
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, in classical physics the state of the world changes
constantly (in a quantum world it is extremely ambiguous...), but the
question of purity of a program - in my opinion - concerns the program,
and nothing else. The networking is not expected to break the
referential transparency, or does it?
Jerzy
, of terminology, of
preconceptions (of all that, what for God knows which reasons, Americans
call just semantics), but I will not forget the day when I thought as
you, and I had to explain to 2-nd year students what does it mean: a
value which doesn't have a value...
Thank you.
Jerzy Karczmarczuk
, it is a beginning of the end. Veeery, very funny...
Imagine an ecclesiastic General Council, and the Pope saying:
Brothers Bishops! Our new dogmas must be absolutely flawless, pure and
sound, otherwise we might as well become Muslims.
Inchaa whatever.
Jerzy Karczmarczuk
Caen, France
Mister Nobody is perfect.
Jerzy Karczmarczuk
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Aleksey Khudyakov:
On 09.02.2012 15:32, Jerzy Karczmarczuk wrote:
1. Mersenne Twister, AND congruential generators AND the Marsaglia
stuff, all use some kind of seed, all are stateful. There are no
miracles. Just look the agressive monadization, the form of defaultSeed,
etc. within MWC.hs
Conal Elliott cites Steve Horne:
I look at this World parameter as purely hypothetical, a trick
used to gain an intuition. Whereas Jerzy (I think) uses it to
claim Haskell is referentially transparent - those differing x and
y values come from different worlds, or different
are you trying to suggest?
You show two OBVIOUSLY different pieces of code, and you say that they
are different.
If, by chance, some newbie reads that and gets the impression that (-)
is something equivalent to (=), you are serving the devil.
Jerzy Karczmarczuk
Yves Parès :
all standard Monads are newtypes wrapping functions
What about Maybe and [] ?
Jerzy Karczmarczuk
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Bardur Arantsson:
Random streams are not referentially transparent, though, AFAICT...?
Either way this thread has gone on long enough, let's not prolong it
needlessly with this side discussion.
Sure.
But the discussion on randomness is /per se/ interesting, especially in
a functional
produce
some side effects.
Jerzy Karczmarczuk
Caen, France.
(William the Conqueror was here. Produced one nice side-effect.)
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Le 29/12/2011 18:01, Iustin Pop a écrit :
I'm confused as what you mean.
And to clarify better my original email: yes, (bar x) always gives you
back the same IO action; but the results of said IO action are/can be
different when executed.
The whole of my point is that it DOESN'T MATTER. (And I
be more fruitful
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The story begins here:
Steve Horne:
/BTW - why use an IO action for random number generation? There's a
perfectly good pure generator. It's probably handy to treat it
monadically to sequence the generator state/seed/whatever but random
number generation can be completely pure. /
Steve Horne :
I only meant that there's random number handling support in the
Haskell library and, and least judging by type signatures, it's pure
functional code with no hint of the IO monad.
Look well at those functions, please.
Within the RandomGen class you have pure members, such as next
Steve Horne :
Some code (intended to be loaded into GHCi and played with)
-- import System.Random
-- randSelect this is a list 5 (mkStdGen 9877087)
-- ...
module P23 (randSelect) where
-- ...
randSelect' (x:xs) n l g = let xsLen = (l - 1)
way, at run-time, Haskell is impure.
Most people here, some VERY knowledgeable, do not agree with you.
/Errare humanum est, perseverare diabolicum/.
Either way, since you insist to prove that you DON'T WANT to understand
other people view, I wish you good luck.
Jerzy Karczmarczuk
don't think that speaking about compile-time purity is correct.
Jerzy Karczmarczuk
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Dear Gurus,
A.
Why the Haskell Platform is still based on ghc 7.03?
(At least on WinXP)
B.
Does anybody care about wxHaskell?
Thanks.
Jerzy Karczmarczuk
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.
Jerzy Karczmarczuk
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of David Fox, I compare it with a
question of a young army officer, addressed to his elders:
Tell me how to win the war in the quickest way possible, rather than
boring me with the explanations behind all those complicated strategies.
Jerzy Karczmarczuk
Caen, Normandy, France
(William
, is lazily allowed.
Best regards
Jerzy Karczmarczuk
Caen, France.
(25 km from the Oldest Comic Strip in the World, 1000 years and progressing)
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OK, these are not slides...
Jerzy Karczmarczuk
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everything...
==
When some years ago we asked our students to write some reports in
English, I thought I would spend some months in the Arkham Asylum, with
Mr. E. Nygma, and others...
Best regards.
Jerzy Karczmarczuk
Caen, Normandy, France
(William the Conqueror started this mess here
there is no problem in
handling those infinite modules. It will just take you an anfinite
amount of time before you get any money from such a work. But this is a
general problem elsewhere as well.
Jerzy Karczmarczuk
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the
details).
Jerzy Karczmarczuk
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Peter Simons :
Now, a person who has profound knowledge of the subject you're asking
about is not very likely to do this, because he is probably not going to
learn anything in the process. Dedicating time and effort to studying
your particular problem is not an appealing prospect.
You might be
at the stars... (Well, actually
I was a fool, but it is a long story).
Jerzy Karczmarczuk
Caen, France
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the
*instances*.
That's why I suggested how you might do that: for some datatypes, say
the Emperors, you specify some special flying method (e.g. dummy or
bombing), or you don't specify it at all. And the Emperors won't fly.
Jerzy Karczmarczuk
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it...
When instancing your Bird class you may forget to define the flying
methods.
Is this unsuitable for you? The compiler will yell, but this is harmless.
Jerzy Karczmarczuk
PS. Penguins DO fly.
http://www.telegraph.co.uk/news/worldnews/1583517/Flying-penguins-found-by-BBC-programme.html
, integrated into Drupal, etc.
I confess I tried to write something which displayed math fromHaskell, I
gave even a project of that kind to my student. But the solutions exist
already and are known, so...
See e.g.
http://www.twingly.com/haskell/stories/4013ffd773e942fdb4b9cf2cb7c0089e
Jerzy
-deterministic return mechanism, but an expression, which yields a
value also for the generator code. It becomes thus a reentrant
co-procedure, which goes quite a mileage beyond the lazy list model.
Jerzy Karczmarczuk
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, and at least two months of a true
course/tutorial (not your pseudo-tutorial on the Web...) we could be
more productive.
That's it...
I don't want to generalize, but there is a huge work to do in this context.
All the best.
Jerzy Karczmarczuk
Caen, France
?...
Jerzy Karczmarczuk
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of the stream of integers,
used to scare the beginners...
ints = 1 : zipWith (+) (fix (1:)) ints
where fix f = f (fix f)
Thanks.
Jerzy Karczmarczuk
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, could you tell me what was the result of the final desugarization
and the BASIC sense of the IO monad for you?
Jerzy Karczmarczuk
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...)
Somebody finally decided to ridiculise the system. If you want a good laugh,
see the patent 6,368,227. The search site is here:
http://patft.uspto.gov/netahtml/PTO/srchnum.htm
Best regards.
Jerzy Karczmarczuk
PS. concerning the patent 7120900. The authors appropriate this
bi-directional
. Or the other way round ; apparently Sönke Hahn is in that
situation, so he fakes...
Jerzy Karczmarczuk
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years. Jeroen Fokker did something then, I worked on it at the same
period. Now Jacques Carette has his own system, and Sergey Mechveliani
another one...
But other people don't care, so the efforts are atomized.
Please, keep cool.
Jerzy Karczmarczuk
says : I know all that,
THEN hurt him badly with monads.
Jerzy Karczmarczuk
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goodmorning to Google.
Jerzy Karczmarczuk
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, then, either you know how to interrupt *any* infinite process
within Haskell, or you have to learn how to do it... Here people more
competent than myself will surely help you. Good luck, and thanks for
your interest in a this fabulous field.
Jerzy Karczmarczuk
the truncation of real randoms?
Jerzy Karczmarczuk
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'randoms' to generate an infinite list of them, 'take' some N, and then
'sum' 1 on randoms filtered by the circle condition. I think that you
won't need full 10 lines of code...
Jerzy Karczmarczuk
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group is a module over integers. But it seems that we are very far from
such a dream.
Jerzy Karczmarczuk
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Hans Aberg writes:
...
But one should also be able to write (f+g)(x). - This does not work in
Haskell, because Num requires an instance of Eq and Show.
So, declare them, even if they are vacuous. I did it several times, I am
still alive, so no need to say this does not work.
Jerzy
common dream...
Jerzy Karczmarczuk
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that f g x fails. It doesn't, in normal order everything
should go smoothly, f g 5 returns 5 = (f g) 5 = g 5, unless I am
terribly mistaken...
Where did you see an error?
Jerzy Karczmarczuk
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recognize that - is syntactically
a right-associative op, so
a-b-c is equivalent to a-(b-c), or
(t-t)-t-t equiv. to (t-t)-(t-t)
Jerzy Karczmarczuk
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://www.thefreecountry.com/compilers/prolog.shtml
You will find there the GNU-Prolog, whose licensing should be as
you wish.
Jerzy Karczmarczuk
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Duponcheel, and Erik Meijer. Available through citeseer.
This has been written under Gofer, should thus work for Hugs, and
no reason why not under GHC.
Very nice paper. (Of course, Rydeheard and Burstall is their first
reference).
Jerzy Karczmarczuk
an auxiliary list, and x not curried away)
times n f x = (iterate f x)!!n
Jerzy Karczmarczuk
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Immediate failure and Delayed
failure. Choose yourselves which is which.
Jerzy Karczmarczuk
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algorithms
may use the equality - after some operation - to check that the machine-
precision convergence has been obtained. On the contrary, the verification
that the absolute value between two terms is less than some threshold,
may be arbitrary or dubious.
Jerzy Karczmarczuk
, this is the opinion of physicists
I spoke to recently.
Never mind. We shall dance over their cadavers, unless they dance over
ours. In both cases we shall be happy.
Jerzy Karczmarczuk
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Yitzchak Gale writes:
Jerzy Karczmarczuk wrote:
Would you say that *no* typical floating-point software is reliable?
It depends on how you define reliable.
Floating point intentionally trades accuracy for speed,
...
It used to be true - and may still be - that the engineers
who
mathematical entities as functional operators, where multiplication
is f. composition. You do it too generically, too optimistically, and then
some octonions come and break your teeth.
So, people *should care*.
Jerzy Karczmarczuk
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different ways will give you different answers. This is *not* a good
way to write reliable software.
[Then we see the scalar product whose value *may* depend on the ev. order]
I wonder...
Would you say that *no* typical floating-point software is reliable?
Jerzy Karczmarczuk
must build a
special Supercomputer for it. It has, BTW. been built, and it is called
the haskell-cafe mailing list.
Jerzy Karczmarczuk
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.
Vou calar a boca...
Gomen nasai.
Jerzy Karczmarczuk
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Tim Chevalier(*) writes:
I think to ease the acceptance of Haskell in the broader world, we
should just change the name to Schönfinkel.
On the other hand, is better not to try Curry, since the French pronounce
it: Queue-rhrhrh. This is for me absolutely inacceptable and scandalous,
since
gozaimasu.
Jerzy Karczmarczuk.
PS. If you think that arigato is a genuine Japanese word, well, check
how the appropriately translated word is spelled in Portuguese...
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you have to add another
schwa, or a Sicilian Variant of that at the end.
Jerzy Karczmarczuk (pronounced as written)
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and communicated. You may kill all the working instances, and
rekindle it later. It such a way it is difficult to kill a religion, or
a political doctrine. But it may die, become useless/unused temporarily.
So, you never really know...
Jerzy Karczmarczuk
because of economical problems...
Jerzy Karczmarczuk
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that it changed now.
Jerzy Karczmarczuk
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, is not a justification to make
false claims, just because this and that had XXX years less than myself in
order to read some easily available texts. Of course, anybody may say
dubious truths, I am ashamed of myself, but from time to time I explode.
Sorry about this.
Jerzy Karczmarczuk
!?
Jerzy Karczmarczuk
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. Then,
a possible solution is to output /some/ random value, and not break the
game. In other words., accept NaNs and infinities, and do with them what
your program requires. YOU take the responsability of raising an exception,
not the system.
Jerzy Karczmarczuk
misunderstand this phrase, but if you suggest that it would be
useful to snatch the code examples from within the book, I believe that
no OCR is needed, they are here:
http://www.iro.umontreal.ca/~lapalme/AlgoFP/code.html
Jerzy Karczmarczuk
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