- Libraries - Haskell.org

something akin to Java's "package" in libraries
by Hal Daume III 27 Feb '02

27 Feb '02

I vaguely recall a brief discussion of this long ago, but don't see any reference to it on the libraries web page. What I had in mind is something like: > package Graphics.GL > module Foo (...) > where > > import X > import Bar.Y > import Z > ... where the first conversion is module-name <- package-name ++ "." ++ module-name the larger issue would be how to convert imports to qualified imports (and module exports to qualified exports). i think (only my opinion) that something like: import X should be qualified to import Graphics.GL.X as X unless Graphics.GL.X doesn't exist, in which case it gets defaulted to import X , similarly for Bar.Y, gets qualified to: import Graphics.GL.Bar.Y as Y unless that doesn't exist, in which case it stays as it is. i suppose this presents a problem if there's a module Y in your package and a module Y which isn't and you want to only import the other one. i'm not entirely sure how java handles this, but from my fairly extensive experience in java, it's done well and i never had any problems with it in 50k+ loc. has this been discussed/considered at all? - Hal -- Hal Daume III "Computer science is no more about computers | hdaume(a)isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume

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Re: Graphics hierarchy
by Ashley Yakeley 27 Feb '02

27 Feb '02

At 2002-02-27 01:07, Ketil Z. Malde wrote: >-- probably elsewhere in the hierarchy >class FileFormat a where > encode :: a -> [Word8] > decode :: [Word8] -> a > > >instance FileFormat PNG where > encode = ... > decode = .. I prefer ML-style structures/functors in this particular instance: data FileFormat a = MkFileFormat { encodeFile :: a -> [Word8], decodeFile :: [Word8] -> Maybe a }; formatPNG :: (Image img) => FileFormat img; formatJPEG :: (Image img) => JPEGCompressionFactor -> FileFormat img; formatUTF8 :: FileFormat String; >class Image a where > rotate :: a -> Int -> a > scale :: a -> Int -> Int -> a > >Maybe compose/blend images? Altering alpha and gamma, color >manipulation? Sounds like a serious project, with the possibility of plenty of complication. -- Ashley Yakeley, Seattle WA

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Control.Monad.Monoid
by Ross Paterson 27 Feb '02

27 Feb '02

Though Monoid is used by several modules in Control.Monad, it doesn't have anything to do with monads itself, so it probably doesn't belong there. Data?

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RE: Graphics hierarchy
by Simon Marlow 27 Feb '02

27 Feb '02

> Simon Marlow wrote: > > Thanks, I'll update my copy of the hierarchy and keep it here: > > http://www.haskell.org/~simonmar/lib-hierarchy.html > > Perhaps a pointer to this and the library document would be useful in > the "about" paragraph at > http://haskell.org/mailman/listinfo/libraries. Good idea; done. Cheers, Simon

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RE: Graphics hierarchy
by Simon Marlow 27 Feb '02

27 Feb '02

> To summarize the recent discussion, here a proposal for a part of the > library organization: Thanks, I'll update my copy of the hierarchy and keep it here: http://www.haskell.org/~simonmar/lib-hierarchy.html at some point I should put this in the main libraries document, and make it clear which modules are part of the "core" libraries. > Format > GIF > JPEG > PNG > TIFF I think we had already agreed to move this sub-hierarchy under FileFormats (see the hierarchy at the link above). > HGL > X11 > Xaw > Xlib > Xmu > Xt > System > POSIX > Files > IO > Process > Win32 Win32 includes both System and Graphics stuff, so shouldn't it go at the top level? > * Whether the POSIX/Win32 hierarchies should be split up on a > functional basis or not has already been debated, but I can't see > any real consensus here. How should we proceed? Someone needs to come up with a proposal and some code, and we go from there :-) Cheers, Simon

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Re: Graphics hierarchy
by Ashley Yakeley 27 Feb '02

27 Feb '02

At 2002-02-27 00:44, Sven Panne wrote: > * It's unclear what Graphics.Format is supposed to do exactly. > Could somebody explain this? Perhaps functions of the form encodePNG :: Image -> [Word8] decodePNG :: [Word8] -> Maybe Image ...? -- Ashley Yakeley, Seattle WA

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RE: Graphics hierarchy
by Simon Marlow 27 Feb '02

27 Feb '02

> The currently proposal for the Graphics hierarchy looks like > this (IIRC): > > Graphics > UI > Drawing > Format > > I propose changing "Drawing" to "Rendering", because this a > more common > term in computer graphics. But I'm no native speaker, so I'd > like to hear > some comments on this. I like "Rendering". > Another problem is that in "real world" APIs the above > subcategeories are > often mixed up a bit. Have a look at the following APIs resp. Haskell > libraries: > > Clean ObjectIO > Direct3D > FRAN > FranTk > Fudgets > Functional Metapost > GIFWriter > GLUT > GTK+ > Haven > HGL > Inventor > MOTIF > OpenGL > Pan > TclHaskell > Win32 > X toolkit intrinsics > Xaw > Xlib > Xmu Ok, I think I might be tempted to put the X libraries in their own hierarchy, because they don't fit completely into either Rendering or UI: Graphics Rendering HGL OpenGL Direct3D Pan FRAN Haven UI ObjectIO FranTk Fudgets Motif Gtk+ GLUT TkHaskell Format GIF PNG JPEG TIFF ... X Xt Xlib Xmu Xaw > Functional Metapost > Inventor I don't know enough about these. > Win32 The Win32 API includes not just Graphics but also Systemy stuff, so there are two options: either it has its own top-level category, or we scatter the various parts of the Win32 API around the hierarchy (a similar problem arises with Posix). I think I prefer the former. Cheers, Simon

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Graphics hierarchy
by Sven Panne 26 Feb '02

26 Feb '02

[ As suggested by The Grand Marshal of Libraries (tm), I'm moving a thread from the HOpenGL list to this one, widening its scope a bit. ] The currently proposal for the Graphics hierarchy looks like this (IIRC): Graphics UI Drawing Format I propose changing "Drawing" to "Rendering", because this a more common term in computer graphics. But I'm no native speaker, so I'd like to hear some comments on this. Another problem is that in "real world" APIs the above subcategeories are often mixed up a bit. Have a look at the following APIs resp. Haskell libraries: Clean ObjectIO Direct3D FRAN FranTk Fudgets Functional Metapost GIFWriter GLUT GTK+ Haven HGL Inventor MOTIF OpenGL Pan TclHaskell Win32 X toolkit intrinsics Xaw Xlib Xmu Where should we put them in the new hierarchy? Do we need more/other subcategories? Cheers, S. -- Sven Panne Fon: +49/89/99567000 Fax: +49/89/99567461 BetaResearch GmbH, Betastr. 1, D-85774 Unterfoehring mailto:Sven_Panne@BetaResearch.de http://www.betaresearch.de

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RE: Graphics hierarchy
by Simon Marlow 26 Feb '02

26 Feb '02

> > The Win32 API includes not just Graphics but also Systemy stuff, so > > there are two options: either it has its own top-level category, > > [...] > > I'd prefer that, too. > > Has anything been decided about POSIX yet? Nope. But I'm thinking that Posix should be divided into two, with the networking stuff going in Network.Posix (an evolution of the current SocketPrim library) and the rest in System.Posix, possibly further subdivided within there. Unfortunately this breaks our rule of naming libraries by functionality, but again I think I prefer System Posix to System Directory Posix IO Posix Time Posix etc. Cheers, Simon

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FW: Straightforward conversion from Int <-> Word
by Simon Peyton-Jones 26 Feb '02

26 Feb '02

Dear library folk Is this as Haskell library issue? Shouldn't this be a blessed function? Simon -----Original Message----- From: Julian Seward (Intl Vendor) [mailto:v-julsew@microsoft.com] Sent: 25 February 2002 16:57 To: jmaessen(a)alum.mit.edu; glasgow-haskell-users(a)haskell.org Subject: RE: Straightforward conversion from Int <-> Word I've found this annoying in the past, and have resorted to hitting it on the head (GHC-specifically) with a blunt instrument: intToNat :: Int -> Word intToNat (I# i#) = W# (unsafeCast# i#) This probably defeats the good intentions of the FFI designers, but it kinda seems like it'll work on all reasonable architectures. J | -----Original Message----- | From: Jan-Willem Maessen [mailto:jmaessen@alum.mit.edu] | Sent: Monday, February 25, 2002 4:46 PM | To: glasgow-haskell-users(a)haskell.org | Subject: Straightforward conversion from Int <-> Word | | | I've cast about a bit and haven't been able to find the appropriate | functionality, so I'm asking here. | | I'd like to convert Int32 to and from Word32 in the good old-fashioned | bitwise fashion (perserving modular arithmetic). I have the following | code to show what I mean: | | intToNat i | | i >= 0 = fromIntegral i | | otherwise = fromIntegral (i - minBound) + negBound | where negBound = fromInteger . negate . toInteger $ | (minBound :: Int) | | One might think that "intToWord32" and "word32ToInt" in lang/Word | would do what I want---but no! These are depracated, and I must use | fromIntegral, which will only perform the conversion correctly for the | portions of the numeric range which overlap. | | How do I do the straightforward conversion module 2^32? I'm sure it's | buried in there somewhere... I can't even turn up an appropriate type | signature, though. | | -Jan-Willem Maessen | | _______________________________________________ | Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users | _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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