Re: [Haskell-cafe] Function Precedence

2008-04-03 Thread Hans Aberg
On 3 Apr 2008, at 07:59, Henning Thielemann wrote: 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. You could define these instances with undefined function implementations anyway. But also in a more cleaner

Re: [Haskell-cafe] Function Precedence

2008-04-03 Thread Hans Aberg
On 3 Apr 2008, at 08:07, Henning Thielemann wrote: Show could be implemented by writing out the function closures, but I think the reason it is not there is that it would create overhead in compiled code. It would also not give referential transparent answers, because the same function

Re: [Haskell-cafe] Re: Function Precedence

2008-04-03 Thread Hans Aberg
On 3 Apr 2008, at 16:07, Chris Smith wrote: This problem is not caused by defining f+g, but by defining numerals as constants. Yup. So the current (Num thing) is basically: 1. The type thing is a ring 2. ... with signs and absolute values 3. ... along with a natural homomorphism from Z

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 11:22, Henning Thielemann wrote: It seems me it may come from an alteration of math conventions: Normally (x) = x, and function application is written as f(x), except for a few traditional names, like for example sin x. So if one reasons that f(x) can be simplified to f x,

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 13:51, [EMAIL PROTECTED] wrote: 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

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 14:27, [EMAIL PROTECTED] wrote: That is possible, of course - I did that, too. But it means that the syntax and semantics do not work together; an invitation to pitfalls. So this ought to be avoided, except if there are no other workarounds. I am more tolerant. The

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 14:27, [EMAIL PROTECTED] wrote: It would be better to write a new Prelude. :-) Oh, yes, our common dream... One may not need to write a wholly new Prelude, by something like: module NewPrelude where import Prelude hiding -- Num, (+). class AdditiveSemiMonoid a where

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 16:20, Loup Vaillant wrote: class AdditiveSemiMonoid a where (+) :: a - a - a Err, why *semi* monoid? Plain monoid would not be accurate? A monoid has a unit: class (AdditiveSemiMonoid a) = AdditiveMonoid a where o :: a The semimonoid is also called semigroup, I

Re: [Haskell-cafe] Function Precedence

2008-04-02 Thread Hans Aberg
On 2 Apr 2008, at 16:30, Brandon S. Allbery KF8NH wrote: While we're at it, what about adding even more classes, like group or ring? Algebra in a whole class hierachy. :-) Only ambition required :-). http://www.haskell.org/haskellwiki/Mathematical_prelude_discussion --- go nuts. There is

Re: [Haskell-cafe] Function Precedence

2008-04-01 Thread Hans Aberg
in algebra, one sometimes writes f of x as x f or (x)f, so that one does not have to reverse the order for example in diagrams. Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-28 Thread Hans Aberg
and lazy evaluation in different context, but it has the disadvantage of hiding away the semantics. Something to think about when designing the next lazy computer language. :-) Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-28 Thread Hans Aberg
On 28 Mar 2008, at 03:03, Ryan Ingram wrote: Another way to defer the evaluation of the second argument of (-+) is like this: (-+) :: a - List a - List a x -+ y = List(f) where f 0 = x f k = case y of List g - g (k-1) This is exactly what the lazy pattern will do at compile-time. Does

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-28 Thread Hans Aberg
On 28 Mar 2008, at 03:03, Ryan Ingram wrote: Another way to defer the evaluation of the second argument of (-+) is like this: (-+) :: a - List a - List a x -+ y = List(f) where f 0 = x f k = case y of List g - g (k-1) This is exactly what the lazy pattern will do at compile-time. Does

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-28 Thread Hans Aberg
I have fixed the problem now. In the last letter, with the Natural class, I had not added instance Num Natural where (N x) - (N y) = N(x - y) which the Ordinal class then in fact has one. Then it turns out that it is merely the fact that show had some cases looking at the list length

[Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
there are not many possibilities of change. Below, (-+) corresponds, for lists, to :, first to head, and rest to tail. Hans Aberg data List a = List(Integer-a) instance Show a = Show (List a) where show (List f) = [ ++ show (f(0)) ++ concat [, ++ show (f(toInteger i))| i-[1

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
want. I had a look at lazy patterns, but could not figure out how to put them in. So thanks again. Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
it data List a = Empty | List(Ordinal - a, Ordinal) Here, if a type T has a default element t, I can represent the empty list by List(\_ - t, 0) making the constructor Empty redundant. Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
, the function, which is constantly (_|_), is a fixed point for the equation defining h. In other words, if you define h' x = undefined then you have h' x = (-+) anything (h anything) in particular, h' x = (-+) (first x) (h (rest x)) But additional explanation is helpful. Thank you. Hans

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
spot when length is 0. Hans Aberg ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Recursion problem in infinite list model

2008-03-27 Thread Hans Aberg
On 27 Mar 2008, at 17:51, Luke Palmer wrote: A more standard way to do this would be: data List a = List (Ordinal - a) Ordinal I used data List a = Empty | (Ordinal-a) :+ Ordinal which might then be simplified by dropping Empty. Hans Aberg

RE: Using Bison as Haskell parser generator

2002-10-17 Thread Hans Aberg
://mail.gnu.org/mailman/listinfo/help-bison [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-bison Hans Aberg ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell

Re: Hugs for MacOS X

2002-07-02 Thread Hans Aberg
the programming is doing the GC by hand. Hans Aberg ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell

Re: Hugs for MacOS X

2002-07-02 Thread Hans Aberg
available. Summing it up, I suspect that choosing development strategies will depend a lot on how to cut development time, even though MacOS X programming in itself should be interesting, in view that it is now one of the more advanced OS's available. Hans Aberg

GMP unboxed number representation

2001-05-03 Thread Hans Aberg
; that is, that would make the use in say GHC easier? (As I think GHC uses GMP, I thought this might the right place to ask for an input). Hans Aberg ___ Hugs-Bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/hugs-bugs

Re: GHC/Happy on MacOS X/Darwin

2001-01-03 Thread Hans Aberg
, any kind of progress is important. (I do not have access to MacOS X right now, so unfortunatley I cannot try out your port.) Hans Aberg ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell

Re: floor broken

2000-02-25 Thread Hans Aberg
ely slow with todays computers. Hans Aberg

Re: Again: Referential Equality

1999-07-28 Thread Hans Aberg
important in constructive math. Then it is interesting that the approach break down in describing all the innards of the runtime object of a computers. Perhaps this is a weak spot of constructive math relative traditional math, then.) Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED]

Re: Again: Referential Equality

1999-07-28 Thread Hans Aberg
some sort to indicate the non-determinism is as good a solution as any. So I just wanted to give a logical description resolving this referential transparency paradox. How one then chooses to wrap it up in a language is another matter; it should then just be something that is convenient to the user.

Re: Again: Referential Equality

1999-07-28 Thread Hans Aberg
. Then, when the ambiguities have been resolved, one proceeds at finding a better notation. Clearly with the new proposal assigning references at once for all at creation time is by construction an ok model. I am happy to see that my intuition seems to work from the cs point of view. :-) Hans Aberg

Re: diagonalization

1999-07-20 Thread Hans Aberg
, and 0 is the first (smallest) ordinal. Then the set of all lists have type list ([A] in Haskell), just as before: one simply extends the possibility of infinities of lists. Hans Aberg

Re: diagonalization

1999-07-20 Thread Hans Aberg
uch an evaluation. If somebody has some good suggestions, let's hear about it. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

RE: Strange lexical syntax

1999-07-01 Thread Hans Aberg
not appropriate, then one ends up with figuring out the meaning of strange syntaxes. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Making system call from Haskell?

1999-06-28 Thread Hans Aberg
. It then depends on what this system() is implemented to do -- doing nothing is legal in ISO C, but on a UNIX computer it calls the Bourne shell, simple but inefficent. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se

Re: installing hugs

1999-06-23 Thread Hans Aberg
updated. Quadra is 68k, I recall. There might be a hope that somebody compiles the sources I and Pablo made for 68k (probably for CFM then), but the state of the matter is as of yet unclear. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page

Re: Reading a character without echoing it

1999-06-22 Thread Hans Aberg
resolve it. -- As far as I know, the C standard does not specify echoing/non-echoing (and line buffering) of the stdin (or its console), but this is something up to the implementer of the C compiler to decide. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED

Re: Guidance on strictness

1999-06-07 Thread Hans Aberg
Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Guidance on strictness

1999-06-06 Thread Hans Aberg
. Then use the heap profiler again to see if you succeeded. In fact your program is a very good example on how the Heap Profiler can be used. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg

Re: how to write a simple cat

1999-06-04 Thread Hans Aberg
expect to know that if one has a category of some sort, it is equivalent to the lambda calculus, or something like that. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member

Re: Church numerals in Haskell

1999-06-03 Thread Hans Aberg
. In real life though, it is very difficult to translate an arbitrarily given lambda expression into a combination of the given primitive set. So for practical purposes, there is no real gain in attempting to use a primitive set as a replacement for lambda expressions. Hans Aberg

Re: Church numerals in Haskell

1999-06-03 Thread Hans Aberg
? -- The difference is that when using the primitive set S only, we subsume the relations in the algebra of lambda expressions, but here we try to express these relations explicitly. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http

Re: Church numerals in Haskell

1999-06-03 Thread Hans Aberg
contain x is a legal expression in Church's calculus, but this expresion becomes equivalent to lambda x.f when O(x)(f) = f is substituted. Here O lambda a b . b, as before. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home

Re: how to write a simple cat

1999-06-03 Thread Hans Aberg
At 20:08 +0200 1999/06/03, Mariano Suarez-Alvarez wrote: A ``category with + and ^ '' is called cartesian closed aditive category, cf MacLane, Category Theory for the Working Mathematician Is this a suggestion or a theorem? Hans Aberg * Email: Hans Aberg mailto:[EMAIL

RE: how to write a simple cat

1999-06-02 Thread Hans Aberg
. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

RE: how to write a simple cat

1999-06-02 Thread Hans Aberg
nentiation is that on the Church integer functionals, these two operations are just the multiplication and exponentiation of those integer functionals. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ *

Re: how to write a simple cat

1999-06-02 Thread Hans Aberg
. But it can be a spin-off for thoughts: A category is essentially an object with I and *, and a functor is a map preserving those. So what about the two other operations, + and ^ ?. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http

RE: View on true ad-hoc overloading.

1999-05-20 Thread Hans Aberg
to await a couple of generations of computer languages, before one can expect such issues be dealt with properly. But then one might see a truly "general purpose" language, where the programmer picks specializations of general features, instead of from a junkyard of specialized features.

Re: View on true ad-hoc overloading.

1999-05-20 Thread Hans Aberg
should be able to recognize and give control to the distinction between A f(B) and void f(B), and it should not impose implicit type conversions causing type conflicts which cannot be resolved. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page

Re: View on true ad-hoc overloading.

1999-05-20 Thread Hans Aberg
he "+" applicable to the other argument types in the class Float as a single function. Then these names are exported by some mechanism, perhaps corresponding to the "using" directive in C++. If a name conflict occurs, one can type +_Int or +_Float, indicating which copy is intended.

Re: Haskell and mathematical objects

1999-05-05 Thread Hans Aberg
time and effort on workarounds, there is something wrong with that language. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: {-# rules

1999-05-04 Thread Hans Aberg
kell the fact even that monads are triples, even less that they have some additional monad relations to fulfill. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: {-# rules

1999-05-04 Thread Hans Aberg
At 10:08 -0700 1999/05/04, peter [EMAIL PROTECTED] wrote: Hans aberg writes: When a group is expressed as a class G having operations e, *, and -1, then implicitly (via well defined semantics), a group is a quadruple, so I don't think the quadruple need be explicit in the Haskell program

Re: Expression power of Haskell

1999-05-04 Thread Hans Aberg
the evaluation of a complex expression. There are two aspects, building an interface and finding en efficient implementation of. So I described the interface. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg

Re: STL Like Library For Haskell

1999-04-29 Thread Hans Aberg
by a repeat of two operations, by taking the successor, or by a transfinite operation, passing to higher ordinals. Using a well ordered set, that seems to be possible. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se

Re: STL for Haskell

1999-04-29 Thread Hans Aberg
e one element", but you do not know which one, that is the very idea of a set. If the result of this foldl varies from implementation to implementation in a significant way you do not want, then either you have chosen a bad f to fold with, or sets should not be used at all.

Re: Returned mail: haskell@CS.YALE.EDU... aliasing/forwarding loop broken

1999-04-28 Thread Hans Aberg
(haskell.org not working, etc.). Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: STL Like Library For Haskell

1999-04-28 Thread Hans Aberg
order on the set of lists with elements in that class, by taking a lexical order, say by taking lower indices having higher order priority. But as in the case of the Boolean algebra, this total order needs not having anything to do with the Ord one is using for mathematical purposes. Hans Aberg

Re: STL Like Library For Haskell

1999-04-27 Thread Hans Aberg
, just as in C++ STL. This total order is normally different from any derivation of Ord, and is just used for sorting purposes. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member

New MacPPC Binary of Hugs98-990319

1999-03-31 Thread Hans Aberg
, the ":r" command now checks the file dates correctly, and reloads the files if they have been altered. The directory demos/cgi is not with this distribution (as MPJ pointed out he had deliberately removed it). Hans Aberg * Email: Hans Aberg mailto:[EMAIL

Re: Permission to distribute the Haskell 98 reports as part of Debian?

1999-03-22 Thread Hans Aberg
, Microsoft could have still used their altered Java. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Hugs98-990319 Beta: MacPPC Binary

1999-03-20 Thread Hans Aberg
. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Hugs 98: Beta release

1999-01-24 Thread Hans Aberg
hugs98-990121-MacPPC-binary.sit.bin and can be unpacked using Stuffit Expander. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

RE: on Haskell-98

1999-01-04 Thread Hans Aberg
At 02:06 -0800 1999/01/04, Simon Peyton-Jones wrote: Perhaps, but I'm not willing to add anything to the library at this stage. Two months ago maybe. Now, no. Perhaps, as soon as Haskell 98 has been finished, it is time to start development of Haskell 99. :-) Hans Aberg

Re: Haskell 98: randomIO

1998-12-02 Thread Hans Aberg
and 1. I have not been able to hack such a function using Hugs' randomIO function. I can think of adding a function getPseudoRandom, which has an extra argument one interates on (same argument always prodcuing the same result). Hans Aberg * Email: Hans Aberg mailto:[EMAIL

Re: Why I hate n+k

1998-11-27 Thread Hans Aberg
(3) above. If I write x: (x + 1) * 2 = f x *: (x + 1) * 2 = f x then in each case, the intention of the author is clear. The first case could perhaps not be handled by Haskell (implicitly dividing with 2), but other languages, computer algebra languages and CLP(R) and such, cou

Re: Why I hate n+k

1998-11-27 Thread Hans Aberg
When resolving such implicit definitions (in the few cases it is possible), one needs something more sophisticated than the simple pattern matching of Haskell, like Grobner bases and stuff. But such things are handled by computer algebra programs. Hans Aberg * Email: Hans

RE: Reduction count as efficiency measure?

1998-11-24 Thread Hans Aberg
dern CPU's are developed as to make more commonly used assembler instructions faster, the only way to find out the speed of the components of a program is to use a profiler. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matem

RE: Reduction count as efficiency measure?

1998-11-24 Thread Hans Aberg
ink I meant? Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: rename class Functor ?

1998-11-16 Thread Hans Aberg
re general categories in Haskell, then I think that one might need changing the name as you propose. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Haskell 98 progress...

1998-11-13 Thread Hans Aberg
that map (return . f) (... return xs ...) should mean mapM (return . f) (... return xs ...) Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org

Re: Haskell 98 progress...

1998-11-13 Thread Hans Aberg
, that is all objects of the form M(a), and monad algebra homomorphisms M(a) - M(b), so one can use this category instead. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member

Re: New beta of Hugs 1.4 (modules *and* type system extensions)

1998-11-13 Thread Hans Aberg
puts it up. Right now it is at ftp://haskell.org/pub/incoming/MacHugs as Mark P Jones pointed out. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http

RE: MonadZero (concluded)

1998-11-09 Thread Hans Aberg
that the MonadPlus is just a monad whose algebras are monoids. So perhaps it should be renamed to reflect that fact. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http

Re: Haskell 98: getting there

1998-11-09 Thread Hans Aberg
converting them to Doubles: So Floats are then are then slower with less precision, and the memory difference requirement is normally not of any importance. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg

Re: Haskell 98

1998-10-26 Thread Hans Aberg
e with the original discussion is that you fail to properly define the underlying semantics, specifically, the general principles on which it depends. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/

Re: Haskell 98

1998-10-26 Thread Hans Aberg
ine \f to denote a free variable, I could assign f := \f + 1, and later bind this \f by the assignment f := \f |- f, which would work out to the increment function. In this example, free variables and symbol table names have a distinctly different behavior.) Hans Aberg * Email:

RE: topdelcs / decls

1998-10-23 Thread Hans Aberg
depending on the context. Some thinking could probably define some widely used relations, like "equal" and "indentical" in the case of aliases. But one can still not ensure that this will suffice for every data structure. Hans Aberg * Email: Hans Aberg mai

Re: declaring properties

1998-10-21 Thread Hans Aberg
monoid on V and a commutative and associative operator as a map Sym(V) - V -- Sym = disjoint union of Sym^p for p = 0 In a computer language, this provides an interface which the compiler can choose an implementation of. Hans Aberg * Email: Hans Aberg mailto:[EMAIL

RE: Haskell in Scientific Computing?

1998-10-16 Thread Hans Aberg
we might do better. Exactly what does this mean that FORTRAN compilers derives a functional program? Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http

RE: Haskell in Scientific Computing?

1998-10-16 Thread Hans Aberg
ht give clues on how Haskell might be extended. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: category theory

1998-10-15 Thread Hans Aberg
At 17:25 +1000 98/10/15, David Glen JEFFERY wrote: Does something like this exist? FWIW, I'm using Hugs 1.4 I gather that "FWIW" is yet another SSMA; what does it mean? Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home

Re: category theory

1998-10-15 Thread Hans Aberg
e of years). Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: category theory

1998-10-15 Thread Hans Aberg
On 15-Oct-1998, Hans Aberg [EMAIL PROTECTED] wrote: I gather that "FWIW" is yet another SSMA; what does it mean? At 01:22 +1000 98/10/16, David Glen JEFFERY wrote: For What It's Worth. Okay... I'll bite. What's SSMA? some such meaningless acronym Hans Aberg

Re: Haskell in Scientific Computing?

1998-10-14 Thread Hans Aberg
generality on the expense of speed. Haskell could probably be made more usable by allowing classes be written in another language and used from Haskell or vice versa. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.

Re: Haskell in Scientific Computing?

1998-10-14 Thread Hans Aberg
At 14:36 -0500 98/10/09, Jan Skibinski [EMAIL PROTECTED] wrote: Could Haskell ever be used for serious scientific computing? ... On Wed, 14 Oct 1998, Hans Aberg wrote: I think you need to define "scientific computing": At 09:57 -0500 98/10/14, Jan Skibinski wrote: I do

Re: Int vs Integer

1998-10-07 Thread Hans Aberg
suggested that all those should be replaced by a single type Binary, if possible. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Int vs Integer

1998-10-06 Thread Hans Aberg
one, I do not have any opinion. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Int vs Integer

1998-09-25 Thread Hans Aberg
. This will simplify the logic, Integers only doing things typical for integers, the binary type only doing typical binary operations (including arithmetic). Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg

Re: Int vs Integer

1998-09-15 Thread Hans Aberg
At 10:58 +0100 98/09/15, Keith S. Wansbrough wrote: The binary operations (*), (+) etc are not commutative on all types, notably Float. Are you sure you are not mixing up the words "commutative" and "associative" here? Hans Aberg * Email: Hans Aberg mai

Re: Int vs Integer

1998-09-14 Thread Hans Aberg
. public: ... }; One then ends up with the same overflow checks as above, but on the same time ensures that dynamic memory allocation is not used for small integers and that integers are packed efficiently. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED

Re: Int vs Integer

1998-09-12 Thread Hans Aberg
(of word size) special treatment may no not so big. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Rambling on numbers in Haskell

1998-08-04 Thread Hans Aberg
At 00:00 +0200 98/08/04, Felix Schroeter wrote: On Mon, Aug 03, 1998 at 04:18:49PM +0200, Hans Aberg wrote: So, why not add a type "Complexify(R)" of a ring R to Haskell? Note that you can't divide in a ring. A type class *roughly* corresponding to a ring is probably Num. Su

Re: RE: Felleisen on Standard Haskell

1998-08-04 Thread Hans Aberg
note that if one want the programs of an earlier version of a computer language should be able top run on a later version, that can be described by a monad. So why not implement an upgrade monad in Haskell? -- It would solve the problem once and for all. Hans Aberg * Email: Hans

Re: numerics in Haskell

1998-08-04 Thread Hans Aberg
ot;for this run of the program I would like to use 10^5 digits" ? My guess is that it means that the libraries are for real, but they deal with arbitrary precision floating numbers. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.mat

Re: Rambling on numbers in Haskell

1998-08-03 Thread Hans Aberg
not add a type "Complexify(R)" of a ring R to Haskell? Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: GHC licence

1998-07-21 Thread Hans Aberg
But the conditions should be spelled out in the copyright notice, I think. I am not an expert on legal wrangling, but if the perceived independence is at stake, one way could be to create a consortium and transfer the copyright to that while retaining the right to develop the product. Hans Abe

Re: GHC licence

1998-07-21 Thread Hans Aberg
way, what does the "I ANAL" you use mean?) Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Structure of monads in an abstract form?

1998-07-05 Thread Hans Aberg
s an exception monad: Let E be the constant functions of Action in M(A), identify A with its image in M(A), and define E(A) = A | E, a subset of M(A). Then the restrictions of the monad operations on M gives an exception monad E. Hans Aberg * Email: Hans

Re: Structure of monads in an abstract form?

1998-07-03 Thread Hans Aberg
or message to the terminal but letting the computations continue. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

Re: Interprocess communications

1998-06-18 Thread Hans Aberg
as function composition, i.e. putting f = cat(file) g = grep(blah) h = wc(-l) then the line above is h(g(f)). Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http

Re: laziness and functional middleware

1998-06-17 Thread Hans Aberg
e with pre-emotive threads I think. Hans Aberg * Email: Hans Aberg mailto:[EMAIL PROTECTED] * Home Page: http://www.matematik.su.se/~haberg/ * AMS member listing: http://www.ams.org/cml/

<    1   2   3   >