- Glasgow-haskell-users

reifying is-a relation
by Jorge Marques Pelizzoni 07 Jan '08

07 Jan '08

Hi, all! I guess what I am about to ask is currently impossible, but as you haskellers always manage to amaze me and there is plenty of new features in GHC I am not familiar with here it goes. Given two type classes A t and B t, I'd like to derive different A t instances depending exactly on whether t is an instance of B. In other words, is it possible to define a class (actually a type-level function) IsB t f such that: IsB t HTrue <=> (B t) exists IsB t HFalse <=> otherwise? If not, is this wish intrisically pointless? Thanks in advance. Cheers, Jorge M. Pelizzoni ICMC - Universidade de São Paulo

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Rank-2 polymorphism and pattern matching
by Jim Apple 07 Jan '08

07 Jan '08

The following won't compile for me isnull :: (forall a . [a]) -> Bool isnull ([] :: forall b . [b]) = True Couldn't match expected type `forall b. [b]' against inferred type `[a]' In the pattern: [] Wrapping it in a constructor doesn't help, though I can define a "null": data NullList = NullList (forall a . [a]) null = NullList [] isnull2 :: NullList -> Bool isnull2 (NullList []) = True Why? Jim

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Re: [Fwd: Re: Problem building hdbc-sqlite3 with ghc 6.8.2]
by Christian Maeder 07 Jan '08

07 Jan '08

Hi Emmanuel, sqlite3 must be installed on your mac, i.e. a file "libsqlite3.dylib". (I don't have it, too.) If it is say under /opt/local/lib you may need to pass "-optl-L/opt/local/lib" to ghc's command line (or set LD_LIBRARY_PATH) HTH Christian manu wrote: > Macintosh:blog_old_with_sqlite3 manu$ ghc --make newArticle.hs -o > new_article.c > gi > [3 of 3] Compiling Main ( newArticle.hs, newArticle.o ) > Linking new_article.cgi ... > ld: atom sorting error for > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziTypes_CSqlite3_closure_tbl and > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziTypes_CStmt_closure_tbl in > /usr/local/lib/HDBC-sqlite3-1.1.3.0/ghc-6.8.2/libHSHDBC-sqlite3-1.1.3.0.a(Types.o) > > ld: atom sorting error for > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziTypes_CSqlite3_closure_tbl and > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziTypes_CStmt_closure_tbl in > /usr/local/lib/HDBC-sqlite3-1.1.3.0/ghc-6.8.2/libHSHDBC-sqlite3-1.1.3.0.a(Types.o) > > Undefined symbols: > "_sqlite3_errmsg", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziUtils_zdwccall_info in > libHSHDBC-sqlite3-1.1.3.0.a(Utils.o) > "_sqlite3_bind_null", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall11_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_bind_text", referenced from: > _sqlite3_bind_text2 in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > "_sqlite3_column_name", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall6_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_total_changes", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall13_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_close", referenced from: > _sqlite3_close_app in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > "_sqlite3_column_text", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall8_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_column_type", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall7_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_libversion", referenced from: > _r6xt_info in libHSHDBC-sqlite3-1.1.3.0.a(Connection.o) > "_sqlite3_finalize", referenced from: > _sqlite3_prepare2 in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > _sqlite3_finalize_app in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > "_sqlite3_changes", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall12_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_open", referenced from: > _sqlite3_open2 in libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > "_sqlite3_bind_parameter_count", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall2_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_step", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall3_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_busy_timeout", referenced from: > _sqlite3_busy_timeout2 in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > "_sqlite3_column_count", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall5_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_reset", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall4_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_column_bytes", referenced from: > > _HDBCzmsqlite3zm1zi1zi3zi0_DatabaseziHDBCziSqlite3ziStatement_zdwccall9_info in > libHSHDBC-sqlite3-1.1.3.0.a(Statement.o) > "_sqlite3_prepare", referenced from: > _sqlite3_prepare2 in > libHSHDBC-sqlite3-1.1.3.0.a(hdbc-sqlite3-helper.o) > ld: symbol(s) not found > collect2: ld returned 1 exit status > > > > > On Jan 4, 2008, at 6:13 PM, Christian Maeder wrote: > >> Please post the full ld error message >> (also to glasgow-haskell-users(a)haskell.org) >> >> C. >> >> manu wrote: >>> Hi Christian >>> >>> yes it did >>> >>> but, when i tried to compile one of my cgi script where I happen to use >>> HDBC.Sqlite3 >>> it fails with similar 'ld' errors... >>> >>> so I can compile HDBC-Sqlite3, but not programs that use the package... >>> >>> Thanks >>> >>> Emmanuel >>> >>> >>> On Jan 4, 2008, at 11:21 AM, Christian Maeder wrote: >>> >>>> Did a final "runhaskell Setup.lhs install" work for you, Emmanuel? >> >> >

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binary-dists for ghc-6.8.2
by Christian Maeder 07 Jan '08

07 Jan '08

Dear all, I've built binary distributions for Mac OS 10.4 (Tiger) based on (better supported) GMP and GNUreadline frameworks and for Solaris 10. http://www.dfki.de/sks/hets/mac/versions/ghc-6.8.2-powerpc-apple-darwin.tar… http://www.dfki.de/sks/hets/intel-mac/versions/ghc-6.8.2-i386-apple-darwin.… The frameworks under http://www.haskell.org/ghc/dist/mac_frameworks/mac_e.htm should do. The Mac binaries have been built using gcc version 4.0.1 (Apple Computer, Inc. build 5367) and a patched Linker.lhs from http://hackage.haskell.org/trac/ghc/ticket/1798 (also the files compiler/main/DriverPipeline.hs and utils/hsc2hs/Main.hs are patched according to http://hackage.haskell.org/trac/ghc/ticket/1395) The PPC binary still features: http://hackage.haskell.org/trac/ghc/ticket/1845 The PPC ghc can be used on Intel Macs with the additional options: -optc-arch -optcppc -opta-arch -optappc -optl-arch -optlppc (but that's slower than an i386 binary). The Intel-Mac binary has also a patched file rts/Exception.cmm for http://hackage.haskell.org/trac/ghc/ticket/1980 (although I don't know if it is a Mac problem at all.) The Solaris 10 binaries have been built using gcc-4.2.2 http://www.dfki.de/sks/hets/pc-solaris/versions/ghc-6.8.2-i386-unknown-sola… http://www.dfki.de/sks/hets/solaris/versions/ghc-6.8.2-sparc-sun-solaris2.t… The sparc binary was built on a "sun4u sparc SUNW,Sun-Fire-280R" using: SRC_HC_OPTS += -optc-mcpu=ultrasparc -opta-mcpu=ultrasparc Maybe these binary-dists are somehow useful. Christian

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GHC 6.8.1 port on FreeBSD-amd64?
by Wilhelm B. Kloke 07 Jan '08

07 Jan '08

As I have got an amd64 machine again, I am returning to my previous porting effort. When I try to build to .hc files on i386 system, I get the following error: > ... > gmake[2]: Entering directory `/usr/home/wb/ghc-6.8.1/libraries/unix' > ../../compiler/stage1/ghc-inplace -package-name unix-2.2.0.0 -hide-all-packages -i -idist/build/autogen -idist/build -i. -Idist/build -Iinclude -#include "HsUnix.h" -#include "execvpe.h" -odir dist/build -hidir dist/build -stubdir dist/build -package base-3.0.0.0 -package directory-1.0.0.0 -O -XCPP -XForeignFunctionInterface -idist/build -H32m -O0 -fasm -Rghc-timing -keep-hc-files -O -c dist/build/System/Posix/Process.hs -o dist/build/System/Posix/Process.o -ohi dist/build/System/Posix/Process.hi > Prologue junk?: .type s32x_ret, @function > s32x_ret: > pushl %ebp > movl %esp, %ebp > > <<ghc: 114363808 bytes, 9 GCs, 2951168/5799936 avg/max bytes residency (2 samples), 33M in use, 0.00 INIT (0.00 elapsed), 0.78 MUT (2.33 elapsed), 0.20 GC (0.23 elapsed) :ghc>> > gmake[2]: *** [dist/build/System/Posix/Process.o] Fehler 255 > gmake[2]: Leaving directory `/usr/home/wb/ghc-6.8.1/libraries/unix' > gmake[1]: *** [make.library.unix] Fehler 2 > gmake[1]: Leaving directory `/usr/home/wb/ghc-6.8.1/libraries' > gmake: *** [stage1] Fehler 2 which I don't understand at all. The build of ghc-6.8.1 for native use on a FreeBSD-6.2 i386 did not cause any problems. Perhaps someone else has done the porting work already. Please give me a note, if anybody is able to provide me a set of files to get the bootstrap further. -- Dipl.-Math. Wilhelm Bernhard Kloke Institut fuer Arbeitsphysiologie an der Universitaet Dortmund Ardeystrasse 67, D-44139 Dortmund, Tel. 0231-1084-257 PGP: http://vestein.arb-phys.uni-dortmund.de/~wb/mypublic.key

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Haddocumentation of 6.8.1
by Daniel Fischer 06 Jan '08

06 Jan '08

Yesterday, doing runghc ./Setup.hs haddock in zlib.0.4.0.1, I noticed that no Haddock docs have been built for my 6.8.1. I followed the usual building steps, which worked with previous GHCs, set XMLDocWays=html, then ./configure make make install make install-docs No library docs (users guide and Cabal manual are fine). I looked around in a couple of Makefiles, tried 'make doc' in libraries, that built docs, but Haddock couldn't make any cross-package links and libraries/index.html links to package/Package-Name.html, which doesn't exist, because it's package/dist/doc/html/package/Package-Name.html. Question 1: How do I get proper library documentation? Question 2: When I build a package via Cabal, is there a way to merge the documentation into the installed library docs (and if yes, how do I do it)? Feature request: Could the README in future please contain information on how to build library documentation properly? Thanks, Daniel

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Redefining built in syntax
by Neil Mitchell 05 Jan '08

05 Jan '08

Hi, I'm getting errors such as: C:/Documents/Uni/packages/base/GHC/Base.lhs:270:12: Illegal binding of built-in syntax: [] When I try and compile GHC/Base.lhs using the GHC API. Is there some flag I can pass to allow the rebinding of built in syntax? Thanks Neil

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there isn't any difference, is there, with unboxed tuples?
by Isaac Dupree 05 Jan '08

05 Jan '08

--> unboxed types in function results are automatically "lifted"... or what was the term meaning they could be _|_, failing to terminate, (because of the function-ness)? --> unboxed tuples are specially restricted to be only allowed, among useful places, in function results. Therefore (... -> ( a, b, c ) ) and (... -> (# a, b, c #)) are identical, assuming both are kind-correct (identical in terms of optimization and semantics, not type equality, of course). Is that right? If so, there's never an excuse to use unboxed tuples except to contain unboxed values (because then you don't have the choice of using boxed tuples, which can only contain boxed values of kind *). ~Isaac

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odd GHC 6.8.2 compile failure
by Isaac Dupree 04 Jan '08

04 Jan '08

linking the compiled stage2 failed when bootstrapping from 6.6.1, with --prefix=$HOME . It's odd because I previously had a 6.8.2 (official x86 Linux bin-dist) installed as root (it's gone now), and I still have a bunch of cabal/hackage packages installed in $HOME that were compiled by that 6.8.2 (in addition to a few things installed by `cabal install` in ~/.cabal/). Do you think that could be confusing the build process, and if it is, is that a bug - and a bug in what? ... make[3]: Leaving directory `/Users/me/programming/cabalz/NotActuallyCabalButMaybeShouldBe/ghc-6.8.2/compiler' make -f Makefile.ghcbin -wr HS_PROG=stage2/ghc-6.8.2 stage2/ghc-6.8.2 make[3]: Entering directory `/Users/me/programming/cabalz/NotActuallyCabalButMaybeShouldBe/ghc-6.8.2/compiler' ../compiler/stage1/ghc-inplace -H16m -O -package ghc -Istage2 -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -Rghc-timing -DGHCI -threaded -fforce-recomp -c main/Main.hs -o stage2/main/Main.o -ohi stage2/main/Main.hi <<ghc: 293758172 bytes, 332 GCs, 8590865/18490044 avg/max bytes residency (5 samples), 42M in use, 0.00 INIT (0.00 elapsed), 0.83 MUT (0.91 elapsed), 0.40 GC (0.43 elapsed) :ghc>> ../compiler/stage1/ghc-inplace -o stage2/ghc-6.8.2 -H16m -O -package ghc -Istage2 -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -Rghc-timing -DGHCI -threaded -fforce-recomp stage2/main/Main.o /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(InstalledPackageInfo.o): In function `sEZA_info': (.text+0x177c4): undefined reference to `prettyzm1zi0zi0zi0_TextziPrettyPrintziHughesPJ_lvl21_closure' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(InstalledPackageInfo.o): In function `sEZA_info': (.text+0x177cb): undefined reference to `prettyzm1zi0zi0zi0_TextziPrettyPrintziHughesPJ_lvl22_closure' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(InstalledPackageInfo.o): In function `sF0s_info': (.text+0x17974): undefined reference to `prettyzm1zi0zi0zi0_TextziPrettyPrintziHughesPJ_lvl21_closure' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(InstalledPackageInfo.o): In function `sF0s_info': (.text+0x1797b): undefined reference to `prettyzm1zi0zi0zi0_TextziPrettyPrintziHughesPJ_lvl22_closure' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(Package.o): In function `shme_info': (.text+0x100d): undefined reference to `base_DataziList_zdsintersperse_info' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(ParseUtils.o): In function `swtq_info': (.text+0xa879): undefined reference to `base_DataziList_zdsintersperse_info' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(ParseUtils.o): In function `swtC_info': (.text+0xa999): undefined reference to `base_DataziList_zdsintersperse_info' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(Version.o): In function `r7DH_info': (.text+0x27d7): undefined reference to `base_TextziParserCombinatorsziReadP_zdschoice_info' /Users/me/HOME/lib/Cabal-1.2.3.0/ghc-6.8.2/libHSCabal-1.2.3.0.a(Version.o): In function `r7DH_srt': (.data+0x454): undefined reference to `base_TextziParserCombinatorsziReadP_zdschoice_closure' collect2: ld returned 1 exit status <<ghc: 20856200 bytes, 4 GCs, 128260/128260 avg/max bytes residency (1 samples), 16M in use, 0.00 INIT (0.00 elapsed), 0.02 MUT (5.00 elapsed), 0.01 GC (0.02 elapsed) :ghc>> make[3]: *** [stage2/ghc-6.8.2] Error 1 make[3]: Leaving directory `/Users/me/programming/cabalz/NotActuallyCabalButMaybeShouldBe/ghc-6.8.2/compiler' make[2]: *** [stage2/ghc-6.8.2] Error 2 make[2]: Leaving directory `/Users/me/programming/cabalz/NotActuallyCabalButMaybeShouldBe/ghc-6.8.2/compiler' make[1]: *** [stage2] Error 2 make[1]: Leaving directory `/Users/me/programming/cabalz/NotActuallyCabalButMaybeShouldBe/ghc-6.8.2' make: *** [bootstrap2] Error 2 ~Isaac

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Is GHC.Base deliberately hidden?
by Adrian Hey 04 Jan '08

04 Jan '08

Hello, Why is it that the haddock docs supplied with GHC omit this module and its exports? Is it because we're not supposed to use them? I'm thinking of the compareInt# function in particular, which I use quite a lot. Thanks -- Adrian Hey

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