Re: Library conventions

Marcin 'Qrczak' Kowalczyk wrote: > stToIO looks better for me. What about declaring that lowercasing > the first letter of an abbreviation consisting of only capital > letters is realized by lowercasing the whole word? [...] OK, this makes sense and the rule is not much more complicated. > > e.g

Re: Library conventions

I *knew* people couldn't resist talking about names! :-) OK, I've invited you to do this, but more than a dozen mails solely about the first item of section 1.1.1 were a little bit surprising... To be more serious: Perhaps I wasn't clear enough about the purpose of these conventions. What they're

Library conventions

After some discussions in the GHC developer mailing lists a small bunch of conventions around library design emerged. Currently things mainly concentrate on naming issues (everybody's delight :-), but it is only meant as a starting point: http://www.informatik.uni-muenchen.de/~Sven.Panne/hslib

Two floating point questions

Is the following behaviour of GHC allowed by the H98 report? -- Foo.hs main :: IO () main = print (0.1234567891234567891 :: Float, 0.1234567891234567891 :: Double) -- panne@jeanluc:~ > ghc Foo.h

Re: type synonyms and monads

red with constructors, field accessors and > variables. [ example deleted ] But this is really a matter of taste. I'm a real friend of variable-free definitions, but from time to time (e.g. in this example) it's IMHO much easier to see what's going on *with* explicit variables

Re: Showing tuples

Mike Jones wrote: > Yes, I do derive Show for MyData. I was surprised it did not work. Deriving works, but GHC currently only contains instance declarations for tuples up to 5 elements, so you have to write you own boring instances for larger ones. *yawn* Cheers, Sven -- Sven Pa

Re: Show class on ADT with function

tions are not an instance of Show, so you have to supply instance Show (a -> b) where showsPrec _ _ = showString "" or add `import ShowFunctions' (in the upcoming GHC 4.07's package lang). Cheers, Sven -- Sven PanneTel.: +

Re: updating file

cess >>= writeFile "xxx" -- hack for hyperstrictness hyper txt | length txt >= 0 = return txt | otherwise = error "never happens" And using hGetBuf{,BA}Full from GHC's upcoming IOExts module would be a completely different way. -- Sven Panne

Re: No more additions to the FFI API...

mand (I'm a little bit reluctant to write the word "subs...be" here, because I have seen versions of Majormdomo which tried to interpret commands in *every* mail). Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik

Re: multilingual programs

it apart from the usual unsafePerformIO-plus-noInline-trickery at the top level. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen

Re: Additions to the FFI API

ng. * Interfaces.C.Pointers is similar to module FFI. So what remains is basically the first item. Could somebody make a detailed proposal how the FFI should handle this character/string stuff? Cheers, Sven -- Sven PanneTel.: +49/89/2178-223

Re: Additions to the FFI API

er, but this is a different story, we are discussing Haskell's primitive FFI and a lib for handwritten (and automatically generated) bindings, not H/Direct. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik

Re: Additions to the FFI API

te between StablePtr (a, Maybe b) StablePtr (a, Maybe a) StablePtr (a, MyOwnModule.Maybe b) ... This is certainly doable, but is this really worth the trouble? I'm not sure and would definitely like to hear some opinions on this topic. Cheers, Sven -- S

Re: Additions to the FFI API

nciples of Ethics and Code of Professional Conduct) :-) Apart from that, I'll have a look at the "real" ADA stuff. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE

Re: Additions to the FFI API

ode that relies on > byte ordering. I don't see any reason for the Haskell FFI to > encourage this. It's not a matter of encouragement, but a matter of necessity: There are a lot of binary file formats out in the real world, and you really need to know if some swapping is needed or

Additions to the FFI API

dian -- are there more esoteric ones? byteOrder :: ByteOrder Comments/suggestions/flames? Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssp

Re: Fw: speed of compiled Haskell code.

is hyperstrict (at least according to my definition :-) : len :: Eq a => [a] -> Int len [] = 0 len (x:xs) | x == x = 1 + len xs This 'x == x' is folklore for getting rid of some space leaks, AFAIK. Cheers, Sven -- Sven PanneT

ANNOUNCE: HOpenGL 0.99 released

/GLUT support under Cygwin/Mingw32 can be found at http://www.informatik.uni-muenchen.de/~Sven.Panne/cygwin/opengl_glut.html HOpenGL should work on Sparc-based platforms, too, but this has not been thoroughly tested yet. Have fun! Sven -- Sven Panne

Re: ghc-4.06-1.src.rpm (was: ghc to be dropped from potato (debian)

could complain to the SuSE support, I wasn't very successful with my attempts... :-( Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellieru

Re: Wanted: mmap or other fast IO

#x27;re currently working > on fixing them. A workaround is not using -O for modules using FFI or readXXXOffAddr. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Mo

Re: HOpenGL

hat. Sigbjorn: I think it's time to release a new version... Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr.

Deprecated features

s, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 mailto:[EMAIL PROTECTED]D-80538 Muenchen http://www.info

Re: record lables overloading

Sven Panne wrote: > Tom Pledger wrote: > > How about using qualified imports of modules? > > [...] > > module Test where > > import qualified QL1 > > import QL2 > > [...] > > You don't even have to use a qualified import for QL1, prefixi

Re: record lables overloading

e module QL1 where most names don't clash). This "lazy" disambiguation is one of the few things of Haskell's module system I really like. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik

Re: ANNOUNCE: Haskell HTML Combinators

myself... :-} What about a grand unified EMACS HTML/XML library? (Erik's, Malcolm's, Andy's, Colin's, and Sven's HTML/XML library) Ooops, forgot Peter, but he would spoil the acronym... :-) Cheers, Sven -- Sven Panne

Default declarations

ngs like vectors, matrices, etc. which contain elements of a polymorphic numeric type. When no good reason for this restriction exists, it should be removed IMHO. This only extends the set of programs which can be compiled, and existing programs don't change their meaning.

The Haskell Wish List Status

heers, Santa P.S.: Some day the Wish List will move to haskell.org, but at the moment my connection to it reminds me of those good old 300baud-days... -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +4

Re: advice wanted on GUI design patterns

rograms this box fiddling should better be hidden in some GUI abstraction (URLs have already been given in this thread). Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-22

ANN: The Haskell Wish List

t from the Haskell community, so head over to the above URL and see how *you* can contribute and improve the Haskell-experience! :-) Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +

Re: Haskell HTTP lib?

cs.gla.ac.uk/mail-www/glasgow-haskell-bugs/msg01147.html Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 ma

Re: Haskell HTTP lib?

real fan of it, and I know that in academia you earn *nothing* for implementing hSeek and friends, but on the other hand, it shouldn't be *that* hard and time-consuming... Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informat

Re: Q: hugs behavior...

ollected in a clever way (describe in SPJ's book, I think), e.g. if there is only one reference into the "middle" of a CAF left, only that part is kept alive. and not the wohle CAF. Comments from Mr. GC? :-) Cheers, Sven -- Sven PanneTe

Re: Licenses and Libraries

nual conversion of .h files into .idl files, which of the dozens of ihc's command line options you need for this simple interfacing to C, etc. Without this, I guess, most *nix people will stick to Green Card and/or the FFI. Cheers, Sven -- Sven Panne

Re: Haskell 98

he CR/LF vs LF is a non-issue here. Lseek's manual pages tell me something about a *byte* offset, not a *character* offset. Related points would be: What does hGetChar exactly mean in the presence of Unicode/UTF-8/... and random access? Cheers, Sven -- Sven Panne

Re: Haskell Parser in Hugs

cky point is dealing correctly with infix ops in the presence of the module system. Any *easy* suggestions for this? Perhaps if I have some spare time... (Hmmm, not very probable at the moment, the weather in Munich is too nice... :-) But I wouldn't mind if somebody else volunteered. Cheers

Re: Importing, hiding, and exporting

tion: What's the rationale of throwing different namespaces together in the hiding clause? Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungsspra

Re: Importing, hiding, and exporting

g = MakeDing 123 in Bar (the exact opposite of an abstract type? :-). Another question: What is visible in Bar when the name of MakeDing is changed to Ding, too? Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informat

Importing, hiding, and exporting

ng in scope (as expected), while Hugs is completely happy with this. Can somebody elaborate on this? Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modelli

Re: Haskell 98

extremely ugly. And another suggestion: Standardize the Socket library in some way, all sensible operating systems have sockets by now (or the OS will vanish soon, anyway, due to the omnipresent internetworking). Hava a look at Java: Even Joe Programmer can write networki

Re: Random Access Files in Haskell

w-bandwidth connections, everybody on the Haskell mailing list can easily reconstruct the original name. Patent pending... "Everything counts in large amounts" (Depeche Mode) :-) Cheers, Sven -- Sven PanneTel.: +49/89/2178

Re: Random Access Files in Haskell

heers, Sven P.S.: The only response was from Ferguson, pointing out possible problems with CR/LF vs LF, but I take Java's point of view: "A newline is a newline is a newline." -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informati

Repositioning Handles

ct that arithmetic is possible on file positions, see e.g. http://www.wotsit.org/. Merging a file position with a handle is even worse, because this keeps the file open even when only the position is needed later. Opinions? Cheers, Sven -- Sven Panne

Re: how to write a simple cat

iscussion if I had written the more general (.|) :: Functor f => f a -> (a -> b) -> f b (.|) = flip fmap instead...:-} Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX :

Re: Announcing Hugs 98

Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 mailto:[EMAIL PROTECTED]D-80538 Muenchen

Re: how to write a simple cat

ength .| (>lenlim)) .| zip [1..] .| map (\(n,l) -> shows n ") " ++ l) .| unlines .| putStr [ This mail is optimised for 1280x1024 in landscape mode... ] Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik

Re: how to write a simple cat

fn lenlim = readFile fn >>= lines .| filter (length .| (>lenlim)) .| unlines .| putStr Whether this is more or less readable than Hannah's version is largely a matter of personal taste. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 L

Re: Portability dreams

rately > preprocessor directives. [...] Hmmm, defining symbols is obfuscating...? \end{sarcasm} Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier-

Re: Portability dreams

a case of typing > 'ghcmake' in a directory that contains at least Main.hs. ... and 'ghcmake MyMain1.hs', 'ghcmake MyMain2.hs', ... should be possible, too. I'd really love to have this for teaching. Cheers, Sven -- Sven Panne

Re: Portability dreams

by isAlphaNum. "Keep the common case simple". As an additional tool it could be nice. Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungsspr

Portability dreams

cripts, Hugs fails with a "Program line next to comment". I stumbled over this when trying a different version of the above program). With a big *sigh*, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FA

Re: Monad question

;= (\xs -> return (filter (\(x:_) -> x /= '.') xs)) or to impress your friends with your higher-order programming skills: ;-) liftM (filter $ (/= '.') . head) $ getDirectoryContents "." The funny Pfail in the error message stems from the fa

Re: Stream of random comments continues

print . head $ ys where (xs,ys) = splitStream (repeat 1) This gives you space usage linear in n... :-( Cheers, Sven -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LF

Re: Note from (deputy) maintainer

Fergus Henderson wrote: > On 05-Nov-1998, Sven Panne <[EMAIL PROTECTED]> wrote: > > [...] Please automatically prefix the subjects with > > something like [haskell], [ghc-bugs], [ghc-users]. > > BTW, this is easily done using majordomo -- you just set the > &q

Re: Note from (deputy) maintainer

reliable. Cheers, Sven P.S.: No, I'm not affiliated with Great Circle Associates! :-) -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellie

Layout rule confusion

rary contains some layout errors. Waiting for enlightment, Sven "Nitpick" Panne -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen

Re: avoiding repeated use of show

= k (s . showChar '\n') format :: ((ShowS -> ShowS) -> ShowS -> a) -> a format c = c id id Example: format (l_ "Foo" . p_ . s_ . p_ . n_) (2+2) "y" True "" => "Fo

Re: Garbage Collection in GreenCard/RedCard/HaskellCOM

should *really* end up in Haskell's standard libs. Admittedly, these are all things having very little to do with the merry world of the lambda calculus, they are of crucial importance if Haskell should be accepted as a non-toy language. -- Sven Panne

Re: Sockets & Green Card

Nothing very concrete, just to get a feeling for what is changing. This has nothing to do with Green Card per se, but both things are needed for some planned/running projects here and I suspect this combination will not be uncommon when existing APIs are ported to Haskell. -- Sven Panne

Re: Monads and their operational behavior

inear manner. GHC's behaviour is even worse: In addition to a large heap, the compiled program needs *lots* of stack space, too. Comments (or excuses :-) from Glasgow? Space leaks like this are lurking in a lot of places in the standard prelude, so it's quite funny that Hugs

Call for parsers, short summary

oteric examples from category theory. -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 mailto:[EMAIL PROTECTED]D

Call for parsers

source-to-source transformations. Don't hesitate, contribute! -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Modellierungssprachen Oettingenstr. 67 mai

Re: Filehandeling with Haskell

and returning a "b" and a list of "a"s, yield an IO action returning a list of "b"s. Here, both "a" and "b" are String. P.S.: Closing the files with hClose would be a good idea... -- Sven Panne

Re: Lexer/Parser for Haskell in Haskell?

http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne/happy-0.99.tar.gz It should work fine with recent Versions of GHC and Hugs. It's basically Happy 0.9a with massaged imports/exports, replacement of a home-made monad with the standard IO monad, and better command line handling. --

Debugging Haskell

ecific to this kind of problem? [Help is desperately needed. Otherwise the Prolog menace is waiting for me again... :-( ] -- Sven PanneTel.: +49/89/2178-2235 LMU, Institut fuer Informatik FAX : +49/89/2178-2211 LFE Programmier- und Model

Haskell library proposal and constructor classes

baz :: Collection a Char => a Char -> a Char baz c = bar c 'a' addRange :: (Enum a, Collection col a) => a -> a -> col a -> col a addRange start end c = foldr add c [start..end] test :: SList Char test = addRange 'a' 'z&#

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