January 2004 - Haskell

class ??? with Haddock
by Wolfgang Jeltsch 07 Jan '04

07 Jan '04

Hello, I have a datatype Relation element1 element2 which derives an Eq instance. In the Haddock-generated documentation the instances section of Relation says (Ord element1, Ord element2, ??? element1 element2) => [...]. Why does Haddock generate this mysterious ??? element1 element2 context? Wolfgang

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New PhD Positions Department of Computing Science, Chalmers University
by Reiner Haehnle 07 Jan '04

07 Jan '04

Please pass on to interested students. Apologies for multiple copies. --------------------------------------------------------------------- New PhD Positions (DEADLINE 15 February 2004! See "How to apply" below) Department of Computing Science, Chalmers University of Technology & Göteborg University Gothenburg, Sweden http://www.cs.chalmers.se/Cs/ The Department has about 80 researchers, half being faculty members and half PhD students. Our focus is on programming logic, type theory, functional programming, formal methods, distributed and concurrent systems, security, algorithms, bioinformatics, interaction design, and language technology, but research is not restricted to these topics. For more information, see http://www.cs.chalmers.se/Cs/Research. PhD positions are for 5 years. There is no tuition fee. A PhD position is a regular job with social benefits; the salary amounts currently to about 20600 SEK per month in the first year (the exact amount depends on teaching duties, usually 20% of your time). Knowledge of Swedish is not a prerequisite for application. English is our working language for research. Both Swedish and English are used in undergraduate courses. Half of our researchers and PhD students are native Swedes; the rest come from more than 20 different countries. Applicants must have a very good undergraduate degree in Computing Science or in a related subject with a strong Computing Science component. They must also have a strong, documented interest in doing research. You may even apply if you have not yet completed your degree, but expect to do so by 1 September 2004. You are also invited to apply for our new International Master's Programme in Dependable Computer Systems, which can help you to obtain the necessary qualification, if you do not yet have it (see http://www.cs.chalmers.se/Cs/Education/dcs/) The School especially welcomes female applicants. How to apply ------------ First, immediately register your intention to apply using the electronic application form on the WWW via http://www.cs.chalmers.se/~reiner/PhD/phd-04-en.thtml The full application should contain 1 A letter of application, listing specific research interests 2 A curriculum vitae 3 Attested copies of degrees and other certificates 4 Copies of relevant work, for example dissertations or articles, that you have authored or co-authored 5 A description of: a previous teaching experience, documented b previous PhD studies, also in other subjects; state financial support obtained for these, if any c previous work experience 6 Letters of recommendation from your teachers or employers *** You MUST include Letters of Recommendation: we typically get over 100 apps, and it is simple not feasible for us to request individual letters *** If you have financial support of your own (industry job, grant, etc.), please state this fact clearly. It will increase your chances to be accepted considerably, because you need not compete for the limited number of fully financed positions. The reference number of this job opportunity is 1/2004. Send your full application (paper mail - application by email cannot be accepted) to Department of Computing Science School of Computer Science and Engineering Chalmers University of Technology 412 96 Gothenburg Sweden to arrive by 15 February 2004. You will know the result of your application by 1 May 2004.

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Reminder: Eclipse workshop at ETAPS conference
by Oege de Moor 07 Jan '04

07 Jan '04

*** Apologies for multiple copies of this reminder *** 2nd Eclipse Technology Exchange workshop March 30, 2004, Barcelona, Spain A satellite event of ETAPS 2004 Invited speaker: Erich Gamma Submission deadline: January 23, 2004 Call for papers: http://web.comlab.ox.ac.uk/oucl/work/oege.de.moor/etxpage/eclipse.html

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Having difficulty with GHC 6.2 -main-is flag on Windows
by Graham Klyne 06 Jan '04

06 Jan '04

Hi, I'm trying to use the new GHC -main-is flag to compile programs from files with module names other than Main, but it doesn't seem to be working. I've tried this under Windows 2000 and Windows XP. Here's my test program: [[ -- HelloWorld.hs -- module HelloWorld where module Main where main :: IO () main = putStrLn "Hello, World" ]] I switch the commented module line as needed below. Sample output in what follows has been cut-and-pasted from a console command window into this email message. ----- Compiling the above without a -main-is flag: [[ D:\Cvs\DEV\HaskellRDF>ghc --make -fglasgow-exts -iC:\Dev\Haskell\Lib\HUnit;C:\De v\Haskell\Lib\Parsec;C:\Dev\Haskell\Lib\Sort;C:\Dev\Haskell\Lib\Dfa -o HelloWorl d.exe HelloWorld Chasing modules from: HelloWorld Compiling Main ( HelloWorld.hs, HelloWorld.o ) Linking ... D:\Cvs\DEV\HaskellRDF>HelloWorld Hello, World ]] ----- Compiling the above with -main-is Main.main: [[ DD:\Cvs\DEV\HaskellRDF>ghc --make -fglasgow-exts -iC:\Dev\Haskell\Lib\HUnit;C:\De v\Haskell\Lib\Parsec;C:\Dev\Haskell\Lib\Sort;C:\Dev\Haskell\Lib\Dfa -o HelloWorl d.exe -main-is Main.main HelloWorld Chasing modules from: HelloWorld Compiling Main ( HelloWorld.hs, HelloWorld.o ) Linking ... D:\Cvs\DEV\HaskellRDF>HelloWorld Hello, World ]] ----- Compiling the above with -main-is HelloWorld.main [[ D:\Cvs\DEV\HaskellRDF>ghc --make -fglasgow-exts -iC:\Dev\Haskell\Lib\HUnit;C:\De v\Haskell\Lib\Parsec;C:\Dev\Haskell\Lib\Sort;C:\Dev\Haskell\Lib\Dfa -o HelloWorl d.exe -main-is HelloWorld.main HelloWorld Chasing modules from: HelloWorld Compiling Main ( HelloWorld.hs, HelloWorld.o ) Linking ... C:/DEV/ghc/ghc-6.2/libHSrts.a(Main.o)(.text+0x87):Main.c: undefined reference to `__stginit_ZCMain' C:/DEV/ghc/ghc-6.2/libHSrts.a(Main.o)(.text+0xa1):Main.c: undefined reference to `ZCMain_main_closure' ]] ----- Finally, changing the source code module name to HelloWorld: [[ D:\Cvs\DEV\HaskellRDF>ghc --make -fglasgow-exts -iC:\Dev\Haskell\Lib\HUnit;C:\De v\Haskell\Lib\Parsec;C:\Dev\Haskell\Lib\Sort;C:\Dev\Haskell\Lib\Dfa -o HelloWorl d.exe -main-is HelloWorld.main HelloWorld Chasing modules from: HelloWorld Compiling HelloWorld ( HelloWorld.hs, HelloWorld.o ) Warning: output was redirected with -o, but no output will be generated because there is no Main module. ]] ----- Repeating the last case with a compiler -v option [[ D:\Cvs\DEV\HaskellRDF>ghc -v --make -fglasgow-exts -iC:\Dev\Haskell\Lib\HUnit;C: \Dev\Haskell\Lib\Parsec;C:\Dev\Haskell\Lib\Sort;C:\Dev\Haskell\Lib\Dfa -o HelloW orld.exe -main-is HelloWorld.main HelloWorld 1>a.tmp Glasgow Haskell Compiler, Version 6.2, for Haskell 98, compiled by GHC version 6 .0.1 Using package config file: C:\DEV\ghc\ghc-6.2\package.conf Hsc static flags: -static *** Chasing dependencies: Chasing modules from: HelloWorld Stable modules: *** Compiling HelloWorld: compile: input file HelloWorld.hs *** Checking old interface for HelloWorld: Compiling HelloWorld ( HelloWorld.hs, HelloWorld.o ) *** Parser: *** Renamer/typechecker: *** Desugar: Result size = 10 *** Simplify: Result size = 10 Result size = 8 Result size = 8 *** Tidy Core: Result size = 8 *** CorePrep: Result size = 10 *** Stg2Stg: *** CodeGen: *** CodeOutput: *** Assembler C:\DEV\ghc\ghc-6.2\gcc -B"C:\DEV\ghc\ghc-6.2\gcc-lib/" -I. -c C:\DOCUME~1\Graham \LOCALS~1\Temp\ghc3332.s -o HelloWorld.o *** Deleting temp files Deleting: C:/DOCUME~1/Graham/LOCALS~1/Temp/ghc3332.s Upsweep completely successful. *** Deleting temp files Deleting: Warning: output was redirected with -o, but no output will be generated because there is no Main module. link(batch): upsweep (partially) failed OR Main.main not exported; not linking. *** Deleting temp files Deleting: ]] And the standard output (captured to a.tmp): [[ ==================== Packages ==================== Package {name = "data", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/data"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSdata"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["haskell98", "lang", "util"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "rts", auto = False, import_dirs = [], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2", "C:/DEV/ghc/ghc-6.2/gcc-lib"], hs_libraries = ["HSrts"], extra_libraries = ["m", "gmp", "wsock32"], include_dirs = ["C:/DEV/ghc/ghc-6.2/include", "C:/DEV/ghc/ghc-6.2/include/mingw"], c_includes = ["Stg.h"], package_deps = [], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = ["-u", "_GHCziBase_Izh_static_info", "-u", "_GHCziBase_Czh_static_info", "-u", "_GHCziFloat_Fzh_static_info", "-u", "_GHCziFloat_Dzh_static_info", "-u", "_GHCziPtr_Ptr_static_info", "-u", "_GHCziWord_Wzh_static_info", "-u", "_GHCziInt_I8zh_static_info", "-u", "_GHCziInt_I16zh_static_info", "-u", "_GHCziInt_I32zh_static_info", "-u", "_GHCziInt_I64zh_static_info", "-u", "_GHCziWord_W8zh_static_info", "-u", "_GHCziWord_W16zh_static_info", "-u", "_GHCziWord_W32zh_static_info", "-u", "_GHCziWord_W64zh_static_info", "-u", "_GHCziStable_StablePtr_static_info", "-u", "_GHCziBase_Izh_con_info", "-u", "_GHCziBase_Czh_con_info", "-u", "_GHCziFloat_Fzh_con_info", "-u", "_GHCziFloat_Dzh_con_info", "-u", "_GHCziPtr_Ptr_con_info", "-u", "_GHCziPtr_FunPtr_con_info", "-u", "_GHCziStable_StablePtr_con_info", "-u", "_GHCziBase_False_closure", "-u", "_GHCziBase_True_closure", "-u", "_GHCziPack_unpackCString_closure", "-u", "_GHCziIOBase_stackOverflow_closure", "-u", "_GHCziIOBase_heapOverflow_closure", "-u", "_GHCziIOBase_NonTermination_closure", "-u", "_GHCziIOBase_BlockedOnDeadMVar_closure", "-u", "_GHCziIOBase_Deadlock_closure", "-u", "_GHCziWeak_runFinalizzerBatch_closure", "-u", "___stginit_Prelude"], framework_dirs = [], extra_frameworks = []} Package {name = "base", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSbase1", "HSbase2", "HSbase3"], extra_libraries = ["HSbase_cbits", "wsock32", "msvcrt", "kernel32", "user32"], include_dirs = [], c_includes = ["HsBase.h"], package_deps = ["rts"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "haskell98", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HShaskell98"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "haskell-src", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HShaskell-src"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["base", "haskell98"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "network", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSnetwork"], extra_libraries = [], include_dirs = [], c_includes = ["HsNet.h"], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "parsec", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSparsec"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "QuickCheck", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSQuickCheck"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "OpenGL", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSOpenGL"], extra_libraries = ["HSOpenGL_cbits"], include_dirs = [], c_includes = ["HsOpenGL.h"], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = ["-lglu32", "-lopengl32"], framework_dirs = [], extra_frameworks = []} Package {name = "GLUT", auto = True, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSGLUT"], extra_libraries = ["HSGLUT_cbits"], include_dirs = [], c_includes = ["HsGLUT.h"], package_deps = ["base", "OpenGL"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "objectio", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/imports"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSobjectio1", "HSobjectio2", "HSobjectio3", "HSobjectio4"], extra_libraries = ["user32", "gdi32", "kernel32", "comctl32", "comdlg32", "shell32", "winmm", "winspool", "ole32"], include_dirs = [], c_includes = [], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "lang", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/lang"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSlang"], extra_libraries = ["HSlang_cbits"], include_dirs = [], c_includes = ["HsLang.h"], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "concurrent", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/concurrent"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSconcurrent"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["base"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "text", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/text"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HStext"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["lang", "parsec"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "net", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/net"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSnet"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["network"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "hssource", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/hssource"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HShssource"], extra_libraries = [], include_dirs = [], c_includes = [], package_deps = ["haskell-src"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "win32", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/win32"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSwin321", "HSwin322"], extra_libraries = ["user32", "gdi32", "winmm", "kernel32", "advapi32"], include_dirs = [], c_includes = [], package_deps = ["haskell98", "lang"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} Package {name = "util", auto = False, import_dirs = ["C:/DEV/ghc/ghc-6.2/hslibs-imports/util"], source_dirs = [], library_dirs = ["C:/DEV/ghc/ghc-6.2"], hs_libraries = ["HSutil"], extra_libraries = [], include_dirs = [], c_includes = ["HsUtil.h"], package_deps = ["lang", "concurrent", "QuickCheck"], extra_ghc_opts = [], extra_cc_opts = [], extra_ld_opts = [], framework_dirs = [], extra_frameworks = []} ]] #g -- ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact

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RE: Haddock and man pages
by Simon Marlow 05 Jan '04

05 Jan '04

> I think there is some software to translate some DocBook > derivate to man > pages. Maybe one could use the DocBook export mechanism of > Haddock for man > page production. Just and idea. Haddock's DocBook output support needs a lot of work - I originally started on the DocBook output before switching to HTML quite early on. The intention was always to have a form of printable output too, and indeed Haddock is internally structured in such a way that adding different output formats shouldn't be too hard. I think having a means for producing man pages would be a big win. Patches gratefully accepted, as always! Cheers, Simon

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Hugs-on-Windows: rebuild for larger programs
by Graham Klyne 05 Jan '04

05 Jan '04

Following my earlier message, I've posted a rebuild of Hugs.exe for MS-Windows, with quadrupled code storage allocation, at: http://www.ninebynine.org/Software/FatHugs.html #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact

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RE: safe array freezing?
by Simon Marlow 05 Jan '04

05 Jan '04

> so, A common idiom when using Control.Monad.ST is to do some > complicated, state using computation to compute a big array which is > then used purely functionally as a read-only array in the rest of the > program. > > to avoid the cost of copying the array at the end, we are > forced to use > 'unsafeFreeze'. it occurs to me that this particular idiom > can actually > be done safely, by adding the following... > > runSTArray :: (forall s . (ST s (STArray s i e))) -> Array i e > runSTUArray :: (forall s . (ST s (STUArray s i e))) -> UArray i e Good idea. I'll add these to Data.Array.ST. Cheers, Simon

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Large programs in Hugs-2003 on Windows
by Graham Klyne 05 Jan '04

05 Jan '04

I've just run into a problem with Hugs-2003 on Windows, where I get the following message: [[ ERROR "D:\Cvs\DEV\HaskellRDF\N3FormatterTest.hs" - Program code storage space exhausted ]] (This is attempting to load a consolidated test harness, so there genuinely is a lot of Haskell code here, for all the unit test cases.) A look around the web suggests that this is due to a predefined limit in Hugs, which requires a recompilation to change. I'm in the process of downloading the source, to look at this. But meanwhile, I have three questions: - am I right, or am I overlooking an option to allow larger programs? (I tried increasing the heap.) Assuming I am right: - does anyone already have a build of Hugs for Windows that can handle larger programs, available for download? (I use the console version, rather than WinHugs -- I tried WinHugs, but that just throws up unexpected syntax errors.) - can anyone point me to instructions for building Hugs on Windows using a freely available compiler? (I have only very old versions of the Microsoft C development software.) #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact

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Haddock and man pages
by Per Larsson 02 Jan '04

02 Jan '04

Hi, When you have a good understanding of a programming library and only need to quickly refresh your memory regarding the type signature of a specific function, etc., I find man pages very convenient. Are there any plans of adding this as an alternative output format in Haddock? If not, maybe I will try to write a patch when I find some spare time, but it would be encouraging to know if this would interest anyone else but myself? Cheers Per

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Haddock and module properties
by Wolfgang Jeltsch 02 Jan '04

02 Jan '04

Hello, the sources of the hierarchical libraries contain things like Portability : portable in the module descriptions. Some of these property descriptions make it into the HTML documentation, some not. I'm looking for a documentation about these things. Why doesn't the Haddock User Guide describe them? Wolfgang

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