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by Manjula Iyer 25 Jun '01

25 Jun '01

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new version of parser combinators
by S. Doaitse Swierstra 23 Jun '01

23 Jun '01

We have been working hard on new versions of the Parser Combinators and AG system, with the following improvements: even better error repairs much faster and simpler basic parsing machine permutation (of different types) and list combinators extensive reporting about repairs made and what was expected the possibility to manipulate your own state during parsing and result construction, using classed based (like monads) interfaces As an example of the permutation combinators we parse a permutation of three elements: 1) a list of 'a's 2) a 'b' 3) an optional 'c' which is described by: permtest :: Parser Char (String, Char, Char) permtest = permute $ (,,) ~$~ pList (pSym 'a') ~*~ pSym 'b' ~*~ pOptSym 'c' pOptSym :: Char -> Parser Char Char pOptSym x = pSym x <|> pSucceed '_' which we try on several inputs resulting in: t permtest "acb" Result: ("a",'b','c') t permtest "cdaa" Errors: Symbol 'd' before 'a' was deleted, because 'b' or ('a')* was expected. Symbol 'b' was inserted at end of file, because 'a' or 'b' was expected. Result: ("aa",'b','c') t permtest "abd" Errors: Symbol 'd' at end of file was deleted, because 'c' or eof was expected. Result: ("a",'b','_') t permtest "" Errors: Symbol 'b' was inserted at end of file, because 'c' or 'b' or ('a')* was expected. Result: ("",'b','_') The manual is still of an earlier version and will be adapted soon. As an example of the combinators we provide a parser for bibtex files, that returns the repairs made to the erroneous entries (as far as we understand the bibtex format). I hope this is useful to you, Doaitse Swierstra

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User Generated Database of Internet Social Communities
by Jeff Cohn 23 Jun '01

23 Jun '01

We have launched a new research database and would appreciate the contribution of you and your students. http://ecultures.homestead.com/ecultures.html A User Generated Database of Internet Social Communities eCultures is a research tool established to address growing need to discover the Internet's vast network of virtual communities around the world. Unlike today's commercialized and non-collaborative search engines, eCultures has taken a new approach to collaborative research by allowing users to immediately share and search under one common database. All submissions are subject to a review. eCultures is a web property of eStrategy Partners, LLC Comments are appreciated! Regards, Jeff Cohn President & Founder eStrategy Partners, LLC Office: 310-546-7539 jcohn(a)estrategypartners.com www.estrategypartners.com "Solutions for eBusiness"

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Re: library Directory.hs
by Marcin 'Qrczak' Kowalczyk 21 Jun '01

21 Jun '01

Tue, 19 Jun 2001 10:23:30 +0200, Nicole Gabler <Nicole.Gabler(a)web.de> pisze: > I have a problem: I need the library Directory.hs. But > there is no directory.hs in {Hugs}/lib/ !! All standard > libraries are there expect of this one. Not exactly: Time and CPUTime are also missing. > Is there any alternative?? You can use another Haskell implementation: ghc - A big and rich compiler. May be hard to install because of dependencies on various tools. Provides many language extensions and libraries. nhc98 - Smaller than ghc but larger than Hugs. Provides a little more than Haskell 98. Compiles faster than ghc but programs execute more slowly. hbc - No longer maintained. Didn't reach Haskell 98. Compiles fast and programs run quite fast. A note about sources of these compilers: nhc98 is written in nice and clean standard Haskell (but I haven't looked deeply); ghc is written in itself and sometimes can be hard to understand; hbc is written in LazyML and almost nobody except its author understands it. Hugs is an interpreter written in C and I'm not sure how clearly it is written. -- __("< Marcin Kowalczyk * qrczak(a)knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK

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RPMs for: GHC version 5.00.2 is available
by Julian Seward (Intl Vendor) 21 Jun '01

21 Jun '01

Thanks once again to Tom and Manuel for building RH6.2 and RH7.x RPMs of ghc-5.00.2. I'll shortly put these RPMs at the usual place, the download pages at http://www.haskell.org/ghc, so you can get them from there too. Note also that a build for Solaris 2.7 (sparc) is also now available. J | -----Original Message----- | From: Manuel M. T. Chakravarty [mailto:chak@cse.unsw.edu.au] | Sent: Thursday, June 21, 2001 3:02 AM | To: Julian Seward (Intl Vendor) | Cc: glasgow-haskell-users(a)haskell.org; haskell(a)haskell.org | Subject: Re: GHC version 5.00.2 is available | | | "Julian Seward (Intl Vendor)" <v-julsew(a)microsoft.com> wrote, | | > The (Interactive) Glasgow Haskell Compiler -- version 5.00.2 | > ============================================================== | > | > We are pleased to announce a new patchlevel release of the Glasgow | > Haskell Compiler (GHC), version 5.00.2. | | For your installation pleasure, RPM packages built on RedHat | are now available. Binary packages built for RedHat 7.x are at | ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386/ghc-5.00.2-1.i38 6.rpm ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386/ghc-prof-5.00.2- 1.i386.rpm and those for RedHat 6.2 are at ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386-rh6.2/ghc-5.00.2 -1.i386.rpm ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386-rh6.2/ghc-prof-5 .00.2-1.i386.rpm The ghc-prof-* packages contain optional libraries for profiling. The packages for 6.2 are courtesy of Tom Moertel. The source rpm used to built the above binaries is at ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/src/ghc-5.00.2-1.src. rpm If you build from the source rpm using an older version of GHC, note that you have to build the system twice if you like to use the interactive environment. The second build should use the compiler generated in the first. Manuel

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RE: hbc
by Julian Seward (Intl Vendor) 21 Jun '01

21 Jun '01

| > I heard rumors that the author went off to some cushy industrial job, | > or is spending all his time writing NetBSD drivers, or something like | > that :^) | | I heard that he had become a recluse and was chasing eclipses | somewhere in South Africa! I heard rumours that the author had nearly completed writing a whole new Haskell compiler, in Haskell, which (presumably) allowed him to move on from the by-now byzantine complexity of hbc. It is further rumoured that this new compiler could boot itself. J

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GHC version 5.00.2 is available
by Julian Seward (Intl Vendor) 21 Jun '01

21 Jun '01

The (Interactive) Glasgow Haskell Compiler -- version 5.00.2 ============================================================== We are pleased to announce a new patchlevel release of the Glasgow Haskell Compiler (GHC), version 5.00.2. The source distribution is freely available via the World-Wide Web and through anon. FTP, under a BSD-style license. See below for download details. Pre-built packages for Linux, FreeBSD, and Solaris(sparc) are also available. Haskell is a standard lazy functional programming language; the current language version is Haskell 98, agreed in December 1998. GHC is a state-of-the-art programming suite for Haskell. Included is an optimising compiler generating good code for a variety of platforms, together with an interactive system for convenient, quick development. The distribution includes space and time profiling facilities, a large collection of libraries, and support for various language extensions, including concurrency, exceptions, and foreign language interfaces (C, C++, whatever). A wide variety of Haskell related resources (tutorials, libraries, specifications, documentation, compilers, interpreters, references, contact information, links to research groups) are available from the Haskell home page at http://www.haskell.org/ GHC's Web page lives at http://www.haskell.org/ghc/ What's new in 5.00.2 ====================== Fixed a few more bugs which turned out to be showstoppers for various people. Symptoms of the fixed bugs are: * Panics in the bytecode (interactive) linker (two different bugs). * Compiled code dies with a segfault (two different bugs). * Interpreted code crashes or acts weird. * A panic in the CPR analyser. * An infinite loop in the strictness analyser. * Nested comments are not properly handled during module chasing. * :module command doesn't accept underscores in module names. * -L<dir> doesn't work on the ghci command line. * Posix.executeFile mistakenly propagates SIGVTALRM to children. * Exceptions during an interactive session cause the UI to forget some important state information. * (a new feature) Packages can now loaded at the ghci prompt. Do ":s -package <packagename>". What's new in 5.00.1 ====================== This is a bug-fix release. Most reported bugs in 5.00 have been fixed, including a substantial number of show-stopping bugs. The system should be much more usable for more people. Upgrading to 5.00.1 is recommended. To all those who tried out 5.00 and reported bugs, we thank you for your feedback and patience. At the moment there is no Win32 build of 5.00 or 5.00.1 available. We decided to push Win32 support to the 5.02 release, so as not to delay 5.00.1 any further. What's new in 5.00 ==================== 5.00 has been majorly revamped since the previous stable version, 4.08.2. This should be a stable release. Major changes since 4.08.2 are: - An interactive system, similar in style to Hugs. You can interactively load and unload modules, run expressions, ask the types of things. Module dependencies are tracked and chased automatically. Combinations of compiled and interpreted modules may be used. All the GHC libraries are available in interactive mode, as are most of the Glasgow extensions to Haskell 98. Compilation in interactive mode (to bytecode) is about three times faster than compiling to object code. - Batch compilation of multiple modules at once, with automatic dependency chasing. For large programs this can halve compilation times, and removes the need for Makefiles. - Enhanced package (library) management system. Packages may be installed and removed from an installation using the ghc-pkg tool. - Initial Unicode support - the Char type is now 31 bits. - Sparc native code generator, giving much faster compilation on sparcs. (Native code generation for x86s has been available for a while). - Improved heap profiling - you can restrict heap profiles by type, closure description, cost centre, and module. - Support for the latest Foreign Function Interface (FFI) proposals. Marcin Kowalczyk's hsc2hs tool is included. - Language extensions: parallel list comprehensions and functional dependencies. - The usual huge collection of bug fixes. Most reported bugs have been fixed. For full details see the release notes: http://www.haskell.org/ghc/docs/5.00/set/release-5-00.html How to get it =============== The easy way is to go to the WWW page, which should be self-explanatory: http://www.haskell.org/ghc/ We supply binary builds in .rpm/.deb form for all you Linux junkies out there, and in InstallShield form for Windows folks. Everybody else gets a .tar.gz which can be installed where you want. Once you have the distribution, please follow the pointers in the README file to find all of the documentation about this release. On-line GHC-related resources =============================== Relevant URLs on the World-Wide Web: GHC home page http://www.haskell.org/ghc/ Haskell home page http://www.haskell.org/ comp.lang.functional FAQ http://www.cs.nott.ac.uk/~gmh/faq.html System requirements ===================== To compile programs with GHC, you need a machine with 32+MB memory, GNU C and perl. This release is known to work on the following platforms: * i386-unknown-{linux,freebsd,mingw32} * sparc-sun-solaris2 Ports to the following platforms should be relatively easy (for a wunderhacker), but haven't been tested due to lack of time/hardware: * hppa1.1-hp-hpux{9,10} * i386-unknown-solaris2 * alpha-dec-osf{2,3} * mips-sgi-irix{5,6} * {rs6000,powerpc}-ibm-aix The builder's guide included in distribution gives a complete run-down of what ports work; an on-line version can be found at http://www.haskell.org/ghc/docs/5.00/building/building-guide.html Mailing lists =============== We run mailing lists for GHC users and bug reports; to subscribe, use the web interfaces at http://www.haskell.org/mailman/listinfo/glasgow-haskell-users http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs There are several other haskell and ghc-related mailing lists on www.haskell.org; for the full list, see http://www.haskell.org/mailman/listinfo/ Please send bug reports about GHC to glasgow-haskell-bugs(a)haskell.org; GHC users hang out on glasgow-haskell-users(a)haskell.org. Bleeding edge CVS users party on cvs-ghc(a)haskell.org.

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Haskell GUI's
by Aaron Roth 21 Jun '01

21 Jun '01

I'm sure this topic has been discussed ad nauseum. I've only been subscribing since January, so forgive me if I reintroduce it. Is there any place where various approaches for a Haskell GUI are being actively discussed? I've seen fragments here and there, namely pages on FranTk, Fudgets, GTK+Haskell, and a request to port the Clean I/O library. I've also read that there is no consensus view on how to do GUI's in Haskell, but is there an active debate somewhere? Or a few other papers? Thanks. Aaron

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library Directory.hs
by Nicole Gabler 19 Jun '01

19 Jun '01

Hi all, I have a problem: I need the library Directory.hs. But there is no directory.hs in {Hugs}/lib/ !! All standard libraries are there expect of this one. I downloaded Hugs from http://www.haskell.org/hugs/. Is there any alternative?? Or did I understand something wrong?? I hope you can help me! Best regards, Nicole ______________________________________________________________________________ Sie surfen im Internet statt im Meer? Selbst schuld! Auf zum Strand: http://lastminute.de/?PP=1-0-100-105-1

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RE: Haskell report typo (bad law for readsPrec)
by Simon Peyton-Jones 19 Jun '01

19 Jun '01

| Another simple alternative is to weaken the the equation by | replacing the variable r by the empty string: [Alternative B:] | | ... | should be the case that | | fst (head (readsPrec d (showsPrec d x ""))) == x Yes, I like this alternative too. I'll implement it. Thank you for spotting it. Simon

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