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RE: [Haskell] non-ASCII characters in Haddock documentation
by Simon Marlow 17 Feb '04

17 Feb '04

> >It may seem so to western europeans, but others may differ. > >A case could be made for UTF-8. > > I tend to agree. Further, the choice of defaulting to > Latin-1 seems a > strange one when much of the rest of the world (well, the > networking world) > seems to be moving towards more universal character set > encodings. We didn't choose Latin-1 over UTF-8: the current situation just reflects the fact that we haven't implemented UTF-8 yet. It's not trivial to expand GHC's current Alex specification to handle the whole Unicode character set. See this message for some musings: http://www.haskell.org/pipermail/glasgow-haskell-users/2003-December/006 094.html Cheers, Simon

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updating graphs non-destructively
by S. Alexander Jacobson 17 Feb '04

17 Feb '04

In imperative languages, updating an object in a graph is an O(1) operation. However, non-destructive update appears to be O(n) with the size of the graph. For example, suppose we were to implement an auction system like eBay: --Data structures data Bid = Bid BidId Auction User Price DateTime data Auction = Auction Seller Title Description [Bid] data User = User UserId Name [Auction] [Bid] --Top level database type Auctions = FiniteMap AuctionId Auction type Users = FiniteMap UserId User type Bids = FiniteMap BidId Bid type Database = (Auctions,Users,Bids) If I want to add a bid, it seems like I have to traverse the whole Database looking for objects that point to the bid. One alternative is to store pointers rather than values e.g. data Bid = Bid BidId AuctionId UserId Price DateTime data Auction = Auction SellerId Title Description [BidId] data User = User UserId Name [AuctionId] [BidId] But that makes graph traversal expensive as each edge traversal then costs O(log n). O(log n) may be okay for this app, but what if I was implementing Friendster/LinkedIn/Tribe/etc.? Is there a better way to think about this? -Alex- _________________________________________________________________ S. Alexander Jacobson mailto:me@alexjacobson.com tel:917-770-6565 http://alexjacobson.com

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RE: [Haskell] non-ASCII characters in Haddock documentation
by Simon Marlow 16 Feb '04

16 Feb '04

> Am Freitag, 13. Februar 2004 01:23 schrieben Sie: > > wolfgang: > > > Hello, > > > > > > how do I insert non-ASCII and maybe even non-Latin-1 characters in > > > Haddock documentation? > > > > > > Wolfgang > > > > Looks like it might be difficult. The haddock lexer src has: > > > > $alphanum = [A-Za-z0-9] > > > > So, non-ascii might not be lexed. > > Hello, > > I meant non-ASCII characters in source code comments like this: > {-| > The execution time of this function is /n³/. > -} > Currently, Haddock seems to copy the bytes making up the > non-ASCII character > verbatim to the HTML file. But since the HTML file doesn't contain a > character set specification, it is illformed and it depends > on the browser how this situation is handled. It shouldn't be too hard to fix this, at least for Latin-1 (full Unicode would be somewhat harder). I'll add it to the TODO list. Cheers, Simon

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RE: [Haskell] non-ASCII characters in Haddock documentation
by Simon Marlow 16 Feb '04

16 Feb '04

> On Mon, Feb 16, 2004 at 10:20:30AM -0000, Simon Marlow wrote: > > Wolfgang Jeltsch <wolfgang(a)jeltsch.net> writes: > > > I meant non-ASCII characters in source code comments like this: > > > {-| > > > The execution time of this function is /n³/. > > > -} > > > Currently, Haddock seems to copy the bytes making up the > > > non-ASCII character > > > verbatim to the HTML file. But since the HTML file > doesn't contain a > > > character set specification, it is illformed and it depends > > > on the browser how this situation is handled. > > > > It shouldn't be too hard to fix this, at least for Latin-1 (full > > Unicode would be somewhat harder). I'll add it to the TODO list. > > While Haskell's source charset is specified as Unicode, Haskell source > files don't specify the byte encoding they use, so any source > file using non-ASCII characters isn't portable. Entrenching Latin-1 > would make the move to Unicode more difficult. True, but GHC currently assumes Latin-1 as the encoding for source files. I don't see it as entrenching Latin-1, just that we only accept Latin-1 encoded source files; at some point in the future we might accept other encodings. Making the same simplifying assumption in Haddock doesn't seem that big a deal. Cheers, Simon

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Wiki manager change
by Keith Wansbrough 16 Feb '04

16 Feb '04

Hi all... the Haskell Wiki http://haskell.org/hawiki/ is under new management. From now on, please contact Shae Erisson <shae(a)ScannedInAvian.com> with your requests, comments, or feedback on the Wiki site - or, of course, improve and extend the site yourself! Thanks all for your contributions - please keep them coming, and make this resource even more useful. Cheers, --KW 8-) Former Haskell Wiki manager -- Keith Wansbrough <kw217(a)cl.cam.ac.uk> http://www.cl.cam.ac.uk/users/kw217/ University of Cambridge Computer Laboratory.

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3d or Nd geometry library?
by Abraham Egnor 16 Feb '04

16 Feb '04

I was somewhat surprised to see that there's only one geometry library on the haskell libraries page, and further dismayed to find that it for the most part only does 2d. It seems like haskell should be a natural fit for higher-order geometric libraries - has anyone heard of such? Abe

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Re: [Haskell] KDevelop & Haskell
by Peter Robinson 15 Feb '04

15 Feb '04

Hi, my intention when writing the Haskell Plugin for KDevelop was mainly to increase the language's publicity, since KDevelop 3.0 is the most popular and mature IDE for Linux/Unix. I know that most of you prefer to use your favourite editor but the real audience are the C/C++/Java/Php/Python/SQL/... programmers who probably haven't heard much about Haskell yet and would like to give it a try. Things like a background parser that checks the syntax continuously can be implemented quite straightforward in KDevelop as soon as i've got a working C++ parser for Haskell. Syntax highlighting is provided by the Kate Plugin. A better integration of Hugs or GHCi is possible (via plugins). At the moment only the GHC plugin that allows the user to build and run the files in the project is implemented. regards, Peter --------- Original Message ----------- From: Gour Subject: Re: [Haskell] KDevelop & Haskell Date: Tue, 27 Jan 2004 02:26:43 -0800 Claus Reinke ([EMAIL PROTECTED]) wrote: > that's why it would be nice if the supported Haskell implementations > we have would also offer the necessary API on top of which such > enhanced IDE functionality could be implemented in everyone's > editors of choice. > > >> But I saw that haskell is in the the table of supported languages. > > > >yes, and it is nice to see it advertised this way, but I just checked, > >and the support seems to be in its very early stages: > >But, it's better than nothing :-) > > >it won't do everything (unless you do a little programming, or we get >> those APIs I keep mumbling about), but it will do a lot. >>Do you have some pointer for discussion(s) about these APIs you're mumbling >>about? >> set your editor as specified, start Hugs, type ":find foldl", enjoy. >> for extra marks, make your editor call out to Hugs, load the current >> module, and :find the identifier under the cursor. (or were you >> suggesting that most Hugs users are already aware of this >> feature and use it every day?) >At the moment (6th ch. of Thompson's Craft of FP) I'm still with Helium :-) >but otherwise I was/am using ghc to compile e.g. darcs and other Haskell >stuff. > > This one is nice. Thank you. > > why, thank you!-) >At the moment I'm compiling HaRE under MSYS/MinGW environment. Where can I >report back? > >Have you (maybe) tried KDevelop with kvim? > > no, I was thinking of the recent Haskell-in-Haskell frontends, and > of Simon M's work on providing an API for ghc to support a > visual studio binding. The frontends, or the API once it has evolved, > are just what one needs to provide programmers editors with > Haskell-awareness. > > http://www.haskell.org/communities/11-2003/html/report.html#sect5.2.3.1 > http://www.haskell.org/communities/11-2003/html/report.html#sect5.3.3 > http://www.haskell.org/communities/11-2003/html/report.html#sect6.5.5 Wow! It looks great. I definitely have to find out some more time in pursuing my learning of Haskell, since there is interesting development going on. (recently I've found few posts on Ruby list with the complain that "but ultimately lost interest because the discussions focused on a /much/ higher level than they do here on the Ruby list--arguments over language design, etc., with few mentions of using Haskell to do anything productive.", so I hope that something like Programatica Project can drastically change the situation and bring Haskell more tho the mainstream (despite the fact if this is the intention of the whole project :-) Thank you for enlighetning me about Programmatica. Sincerely, Gour

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non-ASCII characters in Haddock documentation
by Wolfgang Jeltsch 15 Feb '04

15 Feb '04

Hello, how do I insert non-ASCII and maybe even non-Latin-1 characters in Haddock documentation? Wolfgang

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Re: Making a spreadsheet with Haskell (S.J.Thompson)
by Lloyd Allison 15 Feb '04

15 Feb '04

I am looking at running Haskell code from within gnumeric, the opensource spreadsheet -- it's good. Gnumeric is written in C, using those "autogen" etc. tools, and has quite a nice plugin mechanism, but it does rather rely on whatever compiler is used for the plugin to produce a shared object, which ghc does not do. After much effort, a local guru did manage to "persuade" gnumeric to call a H98 hello-world kind of function but it wasn't easy or pretty. Is there any H98 compiler that can produce a shared object? And out of interest, what is the particular difficulty with ghc? Since it does go through C(?), of sorts, I'd have naively thought it would be possible (of course you get what you pay for, so you can't complain). -L -- > ... > Message: 6 > Date: Sat, 14 Feb 2004 10:28:34 +0000 > From: "S.J.Thompson" <S.J.Thompson(a)kent.ac.uk> > Subject: Re: [Haskell] Making a spreadsheet with Haskell > To: lisper(a)it.kth.se, mcob(a)hps.es > Cc: haskell(a)haskell.org > Message-ID: <E1Arx2I-0002Hx-00(a)myrtle.ukc.ac.uk> > > You could take a look at Vital > http://www.cs.kent.ac.uk/projects/vital/ > >From the web page: > Vital is a visual programming environment based on Haskell, a > contemporary functional programming language. It is particularly > intended for supporting the open-ended, incremental style of > development often preferred by end users (engineers, scientists, > analysts, etc.). It may also be useful for teaching Haskell. > Simon > ... > > etc.

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hs2lhs
by Stenio 14 Feb '04

14 Feb '04

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