Re: [Haskell-cafe] Integer = infinite precision integer? How?

On Fri, 04 Jul 2008 02:49:44 -0400, leledumbo <[EMAIL PROTECTED]> wrote: > Does anyone have an explanation how Haskell implement this? Or a pointer to a > article describing this? GMP is presently used in GHC (at least according to ).

Re: [Haskell-cafe] Integer = infinite precision integer? How?

On Thu, Jul 03, 2008 at 11:49:44PM -0700, leledumbo wrote: > > Does anyone have an explanation how Haskell implement this? Or a pointer to a > article describing this? > -- AFAIK it's implemented via GMP library: http://gmplib.org/ > View this message in context: > http://www.nabble.com/Intege

[Haskell-cafe] Integer = infinite precision integer? How?

Does anyone have an explanation how Haskell implement this? Or a pointer to a article describing this? -- View this message in context: http://www.nabble.com/Integer-%3D-infinite-precision-integer--How--tp18273875p18273875.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.

[Haskell-cafe] Existential Data Types

Hello I've been doing some stuff with existential data types and came across a curious pattern. If anyone has thoughts, comments, or feedback, it would be appreciated. --- I'm trying to port and extend the Be messaging scheme to Haskell for use in distributed, heterogenous environments. B

[Haskell-cafe] Wouter Swierstra style extensible records!

Having made over-use of Wouter's expression idioms, I decided to hack it into extensible records. It's not documented, it's probably got holes in its usability, but I thought I'd post it so people can play with it (and give suggestions before I rewrite my code to use it!). I know there are other e

Re: [Haskell-cafe] Type families versus functional dependencies question

Alexey Rodriguez: We are having trouble with the following program that uses type families: > class Blah f a where > blah :: a -> T f f a > class A f where > type T f :: (* -> *) -> * -> * the following function does not type: > wrapper :: forall a f . Blah f a => a -> T f f a > wrapper

Re: [Haskell-cafe] Alternatives to convoluted record syntax

> For access to nested record fields I implemented the record-access > package. Unfortunately the field accessors must still be written manually. >http://darcs.haskell.org/record-access/src/Data/Accessor/Example.hs I looked for this on hackage, but found instead this: http://hackage.haskell.

Re: [Haskell-cafe] Re: A Monad for on-demand file generation?

Hi, Am Donnerstag, den 03.07.2008, 11:35 -0700 schrieb David Roundy: > On Thu, Jul 03, 2008 at 07:09:58PM +0100, ChrisK wrote: > > Joachim Breitner wrote: > > You are violating the monad laws. (f >> k) and (f >>= \_ -> k) > > should do the same thing. You might write a version of liftIO that > >

Re: [Haskell-cafe] Type families versus functional dependenciesquestion

actually, GHC gives me "could not deduce Blah f a from Blah f1 a" first. It seems that desugaring type function notation into an additional constraint helps, so there's something odd going on: Silly me, I didn't paste the whole type error. Yes, GHC gives both. I should add that I tested this und

Re: [Haskell-cafe] Access to Oracle database from Haskell

On Mon, 30 Jun 2008, Alistair Bayley wrote: I haven't found a way to detect where headers are installed, so I propose that the Setup.hs assumes $ORACLE_HOME/rdbms/public (for Unix), and you can add more with --extra-include-dirs=... . What do you think? Many thanks for including the necessary

Re: [Haskell-cafe] Type families versus functional dependencies question

On Thu, Jul 3, 2008 at 7:31 PM, Claus Reinke <[EMAIL PROTECTED]> wrote: > GHC gives the error: >> >> Couldn't match expected type `T f1 f1 a' >> against inferred type `T f f a' >> In the expression: blah x >> In the definition of `wrapper': wrapper x = blah x >> > > actually, GHC gi

Re: [Haskell-cafe] Re: A Monad for on-demand file generation?

On Thu, Jul 03, 2008 at 07:09:58PM +0100, ChrisK wrote: > Joachim Breitner wrote: > > * The 5th line does not have this effect. Because this gets desugared > >to (>>), the special implementation of (>>) means that the next line > >still sees the same dependency state as the before the call to liftI

[Haskell-cafe] Re: A Monad for on-demand file generation?

Joachim Breitner wrote: * The 5th line does not have this effect. Because this gets desugared to (>>), the special implementation of (>>) means that the next line still sees the same dependency state as the before the call to liftIO. You are violating the monad laws. (f >> k) and (f >>= \_ ->

Re: [Haskell-cafe] Type families versus functional dependencies question

GHC gives the error: Couldn't match expected type `T f1 f1 a' against inferred type `T f f a' In the expression: blah x In the definition of `wrapper': wrapper x = blah x actually, GHC gives me "could not deduce Blah f a from Blah f1 a" first. It seems that desugaring type fu

Re: [Haskell-cafe] Re: A Monad for on-demand file generation?

Hi, Am Donnerstag, den 03.07.2008, 15:55 +0200 schrieb Joachim Breitner: > I have some code that I’ll put somewhere soon. http://darcs.nomeata.de/odio/ODIO.hs now contains a simple implementation of the idea, together with more explanation. To show what the effect is, I wrote a very small program

Re: [Haskell-cafe] Re: A Monad for on-demand file generation?

Hi, Am Mittwoch, den 02.07.2008, 16:43 +0100 schrieb ChrisK: > > hen, the readFileOD could put the timestamp > > of the read file in a Monad-local state and the writeFileOD could, if > > the output is newer then all inputs listed in the state, skip the > > writing and thus the unsafeInterleaveIO’e

[Haskell-cafe] Type families versus functional dependencies question

Hi guys, We are having trouble with the following program that uses type families: > class Blah f a where > blah :: a -> T f f a > class A f where > type T f :: (* -> *) -> * -> * the following function does not type: > wrapper :: forall a f . Blah f a => a -> T f f a > wrapper x = blah x

Re: [Haskell-cafe] ANN: The Disciplined Disciple Compiler - alpha 1.1

Is there any work on combining effect typing with extended static checking or full-blown formal verification (e.g. proof-carrying code)? My hunch would be that an impure functional language like this (OCaml is another example) makes optimisation easier, compared to Haskell - but at the expense of m

[Haskell-cafe] parallel_map_reduce, in easy one liner mod

Hi haskellers, So.. the type says it all p_map_reduce :: ([a] -> b) -> (b -> b -> b) -> [a] -> b so the idea is to write your computation extensive funciton as a map_reduce function, simplest example: sum ( can be seen as map id then reduce (+) ) then instead of calling: sum xs just call: p

Re: [Haskell-cafe] type classes

Hi Henning, The numeric prelude was inspiration for a lot of my design. Part of the reason I didn't use it was because one of my goals is to learn Haskell better, and I wanted to grapple with these design decisions myself. I decided, like IsZeroTestable in the numeric prelude, to make zero/one s

Re: [Haskell-cafe] Re: type classes

A number of operations -- like order above -- are conceptually connected not to the elements but to the structures themselves. Here is the outline of a more complicated example. I also have a vector space class class VectorSpaceTy a b | a - > b where dimension :: a -> Integer basis :: (Field

[Haskell-cafe] ANN: The Disciplined Disciple Compiler - alpha 1.1

Hi All, I'm pleased to announce version 1.1 of the Disciplined Disciple Compiler (DDC) Disciple is an explicitly lazy dialect of Haskell which supports: - first class destructive update of arbitrary data. - computational effects without the need for state monads. - type directed field proj

Re: [Haskell-cafe] Alternatives to convoluted record syntax

On Thu, Jul 3, 2008 at 8:00 PM, Dougal Stanton <[EMAIL PROTECTED]> wrote: > Here's a snippet from the parser for one option (others omitted for clarity): > >> options :: [OptDescr (Opts -> Opts)] >> options = >> [ Option "b" ["bus"] (ReqArg busNum "NUM") "Bus number" >> , ... >> ] >>

Re: [Haskell-cafe] Alternatives to convoluted record syntax

On Thu, Jul 3, 2008 at 11:13 AM, Henning Thielemann <[EMAIL PROTECTED]> wrote: > > infix2 :: ((Char, Int), String) > infix2 = > (('b',7),"hallo")$%first^:second^=10 > > (second^=10) replaces the second member of pair with a value. > (^:) applies that change to the outer record (again a pair). >

[Haskell-cafe] Re: type classes

Slightly off-topic - but I'm curious to know why you want objects representing the structures as well as the elements - what will they be used for? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-ca

Re: [Haskell-cafe] Alternatives to convoluted record syntax

On Thu, 3 Jul 2008, Dougal Stanton wrote: Here's a snippet from the parser for one option (others omitted for clarity): options :: [OptDescr (Opts -> Opts)] options = [ Option "b" ["bus"] (ReqArg busNum "NUM") "Bus number" , ... ] where busNum n os = let b = (query os) { queryBu

[Haskell-cafe] Alternatives to convoluted record syntax

Hi Haskellers, This is a style question, as my program works fine but looks really ugly and can be confusing to maintain. I take options from the command line using GetOpt and hand back this structure for later use. > data Opts = Opts > { query :: Query > , queryLimit:: Maybe