- Glasgow-haskell-users

Re: Extensible Records
by Barney Hilken 13 Nov '07

13 Nov '07

I think this would be a BIG mistake. Whatever system GHC settles on is almost certain to become part of the Haskell standard, and this particular system has some deep limitations which could not be got round without ripping it all out and starting again. The problem with this (and other "Flex-like") systems is that they take record extension as the basic operation of record building, rather than record merging. This means that you can only ever add or update statically determined fields of a given record. An important application which is made impossible by this approach is functions with optional arguments. For example, if you look at the definition of R (the statistics system) every function has a small number of mandatory positional arguments, and a very large number of optional named arguments, which take sensible default values. I want to be able to write: > f opts x = let vals = {Opt1 =: default1, ... } |: opts in > ... vals ... x ... where '{Opt1 =: default1, ... }' is some fixed record of default values, and '|:' is record overwrite. The type of f should be > f :: (a `Subrecord` {Opt1 :=: t1, ...}) => a -> b -> c where '{Opt1 :=: t1, ...}' is the (fixed) type of '{Opt1 =: default1, ... }' (and x::b, and c is the type of the result). The condition 'a `Subrecord` {Opt1 :=: t1, ...}' in the context of this type means that every field of 'opts :: a' must be a field of '{Opt1 :=: t1, ...}', but opts can have as few fields as you like. This is exactly what you want for optional arguments. This could never be defined in any "Flex-like" system, because these systems depend on the fact that their record types can be reduced to a type variable extended by a fixed set of labels. This is a major restriction to what you can do with them: you can never define operations like '|:' or '+:' where the second argument does not have a constant set of fields. This restriction does not hold for more flexible systems like that defined by Oleg & co using functional dependencies, or the one I proposed on this list using type families. Although these systems are much more flexible than the "scoped labels" system, they would take LESS work to add to GHC because they have less built-in syntax, and are almost entirely defined in a library. I second the call for a records system, but please don't limit us to something like scoped labels! Barney.

6 9

Extensible Records
by Voldermort 12 Nov '07

12 Nov '07

Is there any chance of seeing extensible records in GHC 6.10? There seems to be widespread agreement that the current situation is unacceptable, but the official GHC policy is that there are too many good ideas to choose from - so nothing gets done! I hence humble propose that http://www.cs.uu.nl/~daan/download/papers/scopedlabels.pdf be adapted to GHC. In my naivete, I assume that porting an existing implementation would be much easier than starting from scratch. Is this reasonable? N.B. I am aware that GHC has limited resources - many thanks to Simon & Simon and all other contributors either way.

5 7

missing Control.Monad.State
by Hal Daume III 12 Nov '07

12 Nov '07

Hi all -- Something weird just happened and I feel bad asking on the list for help (because it's a dumb question), but I've racked my brains and can't figure it out. I've been happily using ghc for some time now. My current machine died, and the computer folks gave me a new one. Both my old and new were running ubuntu. The new machine came in and I apt-get installed ghc6 ghc6-prof ghc6-docs haskell-mode ghc6-libsrc. But when I try to run ghc on a module that uses Control.Monad.State, I get: ~ ghc --make -fglasgow-exts Main.hs -o hbc Core.hs:24:7: Could not find module `Control.Monad.State': Use -v to see a list of the files searched for. If I say -v, I get: Glasgow Haskell Compiler, Version 6.6, for Haskell 98, compiled by GHC version 6.6 Using package config file: /usr/lib/ghc-6.6/package.conf wired-in package base mapped to base-2.0 wired-in package rts mapped to rts-1.0 wired-in package haskell98 mapped to haskell98-1.0 wired-in package template-haskell mapped to template-haskell-2.0 Hsc static flags: -static *** Chasing dependencies: Chasing modules from: Main.hs Core.hs:24:7: Could not find module `Control.Monad.State': locations searched: Control/Monad/State.hs Control/Monad/State.lhs *** Deleting temp files: Deleting: *** Deleting temp dirs: Deleting: Looking in /usr/lib/ghc-6.6/package.conf, I don't find any mention of Control.Monad.State (or anything with "State") for that matter. A "find" in /usr/lib/ghc-6.6 doesn't turn up anything called State, either. I presume that I'm doing something incredibly stupid, but I'd appreciate a bit of help! Thanks! - Hal -- Hal Daume III --- me AT hal3 DOT name | http://hal3.name "Arrest this man, he talks in maths." | http://nlpers.blogspot.com

3 2

GHC and dynamic linking
by Richard Giraud 11 Nov '07

11 Nov '07

I foggily remember previous versions of GHC being unable to create programs that use dynamic links to libraries. Is this the case and, if so, is it still an issue? Static linking is not an option due to licensing issues. I'm interested in GHC 6.6.1 and 6.8.1 on Windows, Mac (PowerPC and x86), and Linux (x86). Thanks in advance, Richard

2 1

ghc-6.8.1 under Solaris
by Christian Maeder 11 Nov '07

11 Nov '07

Dear Solaris Users, binary distributions for Solaris 10 ultrasparc and i383 can be found at: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… Both distributions (like those for ghc-6.6.1) require the following dynamic libraries (among others): libreadline.so.5 libncurses.so.5 libm.so.2 libgmp.so.3 (possibly set LD_LIBRARY_PATH on your system) If configure only finds ./install-sh, you need to call: ./configure INSTALL=`pwd`/install-sh --prefix=.... gmake install (or edit Makefile-vars after configure manually: http://hackage.haskell.org/trac/ghc/ticket/1810#comment:1) Cheers Christian P.S. a build slave under Solaris would be quite useful (to improve the shell hacks).

2 1

GHC 6.8.1 on Mac OS X 10.4 (Tiger)
by Christian Maeder 11 Nov '07

11 Nov '07

Dear Tiger Mac-users, binary distributions of GHC 6.8.1 for Mac OS X 10.4 (Tiger) are stored at: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… and http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… As for ghc-6.6.1 both distributions rely on (the "universal") GMP and GNUreadline frameworks found at: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… instructions at: http://www.informatik.uni-bremen.de/agbkb/forschung/formal_methods/CoFI/het… The ppc distribution features the bug: http://hackage.haskell.org/trac/ghc/ticket/1845 Only HADDOCK documentation is included. (The message at the end of an installation is wrong anyway, because a wrong directory is tested: Warning: this binary distribution does NOT contain documentation!) I haven't checked the installation against a test-suite (could someone put one up for download?), but the distributions work for our purposes and might be useful for you, too. Christian

3 2

Odd error report against ghc-6.8.1
by ChrisK 11 Nov '07

11 Nov '07

thomas.hartman(a)db.com has sent me a new bug report. Apparently he can crash ghc-6.8.1 when compiling regex-tdfa-0.93 (darcs under http://darcs.haskell.org/packages/regex-unstable/regex-tdfa/ ). Should I open a ticket for this? > > I darcs got the newest regex-tdfa (0.93 iirc) and made all the obvious changes involving LANGUAGE/OPTION_GHC pragmas to get this to work on ghc-6.8.1 > > prereq regex_base 0.93 installs ok > regex-tdfa panics with > > hartthoma@linuxpt:~/installs/regexstuff/regex-newest/regex-tdfa>runghc Setup.hs build > Preprocessing library regex-tdfa-0.93... > Building regex-tdfa-0.93... > [ 1 of 21] Compiling Data.IntMap.CharMap ( Data/IntMap/CharMap.hs, dist/build/Data/IntMap/CharMap.o ) > > Data/IntMap/CharMap.hs:9:27: > Warning: Imported from `Data.Char' but not used: `chr' > [ 2 of 21] Compiling Data.IntSet.EnumSet ( Data/IntSet/EnumSet.hs, dist/build/Data/IntSet/EnumSet.o ) > [ 3 of 21] Compiling Data.IntMap.EnumMap ( Data/IntMap/EnumMap.hs, dist/build/Data/IntMap/EnumMap.o ) > [ 4 of 21] Compiling Text.Regex.TDFA.IntArrTrieSet ( Text/Regex/TDFA/IntArrTrieSet.hs, dist/build/Text/Regex/TDFA/IntArrTrieSet.o ) > [ 5 of 21] Compiling Text.Regex.TDFA.Common ( Text/Regex/TDFA/Common.hs, dist/build/Text/Regex/TDFA/Common.o ) > [ 6 of 21] Compiling Text.Regex.TDFA.Pattern ( Text/Regex/TDFA/Pattern.hs, dist/build/Text/Regex/TDFA/Pattern.o ) > [ 7 of 21] Compiling Text.Regex.TDFA.ReadRegex ( Text/Regex/TDFA/ReadRegex.hs, dist/build/Text/Regex/TDFA/ReadRegex.o ) > [ 8 of 21] Compiling Text.Regex.TDFA.CorePattern ( Text/Regex/TDFA/CorePattern.hs, dist/build/Text/Regex/TDFA/CorePattern.o ) > ghc-6.8.1: panic! (the 'impossible' happened) > (GHC version 6.8.1 for i386-unknown-linux): > splitFunTy > <nt>mtl-1.1.0.0:Control.Monad.RWS.Lazy.RWS{tc rsRo} > (base:Data.Maybe.Maybe{tc r6} > regex-tdfa-0.93:Text.Regex.TDFA.Common.GroupIndex{tc raaa}) > [base:Data.Either.Either{tc 344} > regex-tdfa-0.93:Text.Regex.TDFA.Common.Tag{tc raai} > regex-tdfa-0.93:Text.Regex.TDFA.Common.GroupInfo{tc raa4}] > ([regex-tdfa-0.93:Text.Regex.TDFA.Common.OP{tc raae}] > -> [regex-tdfa-0.93:Text.Regex.TDFA.Common.OP{tc raae}], > regex-tdfa-0.93:Text.Regex.TDFA.Common.Tag{tc raai}) > (base:GHC.Prim.Any{(w) tc 31N}, > [regex-tdfa-0.93:Text.Regex.TDFA.Common.Tag{tc raai}]) > > Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Note that "Text.Regex.TDFA.Common.Tag" is "type Tag = Int" and compiling the CorePattern.hs file works fine under ghc-6.6.1. The only unusual thing in CorePattern is the use of "mdo" recursive-do syntax. His message continues with the steps he used, and the minimal patch that got it from ghc-6.6.1 to ghc-6.8.1 : > > hartthoma@linuxpt:~/installs/regexstuff/regex-newest/regex-tdfa>runghc Setup.hs configure > Configuring regex-tdfa-0.93... > hartthoma@linuxpt:~/installs/regexstuff/regex-newest/regex-tdfa>runghc Setup.hs build > Preprocessing library regex-tdfa-0.93... > Building regex-tdfa-0.93... > > Text/Regex/TDFA/MutRunBS.hs:12:17: > Could not find module `Data.ByteString.Base': > Use -v to see a list of the files searched for. > hartthoma@linuxpt:~/installs/regexstuff/regex-newest/regex-tdfa>darcs whatsnew > { > hunk ./Text/Regex/TDFA/CorePattern.hs 1 > +{-# OPTIONS_GHC -XRecursiveDo #-} > hunk ./Text/Regex/TDFA/RunMutState.hs 1 > -{-# LANGUAGE CPP #-} > +{-# OPTIONS_GHC -fglasgow-exts -XCPP #-} > + > hunk ./regex-tdfa.cabal 16 > -Build-Depends: regex-base >= 0.80, base >= 2.0, parsec, mtl > +Build-Depends: regex-base >= 0.80, base >= 2.0, parsec, mtl, containers, array, bytestring > hunk ./regex-tdfa.cabal 45 > -GHC-Options: -Wall -Werror -O2 -funbox-strict-fields > +GHC-Options: -Wall -Wwarn -O2 -funbox-strict-fields > } > hartthoma@linuxpt:~/installs/regexstuff/regex-newest/regex-tdfa> > >

2 1

6.8.1 compilation error on Sun Solaris 9
by Robert Andersson 11 Nov '07

11 Nov '07

Hello! When compiling on Sun Solaris 5.9 sun4u sparc with configure ./configure --with-gmp-includes=/opt/csw/include --with-gmp-libraries=/opt/csw/lib --with-ghc=/usr/local/ghc/bin/ghc using gcc version 4.0.2 I get the following errors ---------- errors start ---------- == gmake all -r; in /usr/local/src/ghc-6.8.1/compiler ------------------------------------------------------------------------ /usr/local/ghc/bin/ghc -H16m -O -istage1/utils -istage1/basicTypes -istage1/types -istage1/hsSyn -istage1/prelude -istage1/rename -istage1/typecheck -istage1/deSugar -istage1/coreSyn -istage1/vectorise -istage1/specialise -istage1/simplCore -istage1/stranal -istage1/stgSyn -istage1/simplStg -istage1/codeGen -istage1/main -istage1/profiling -istage1/parser -istage1/cprAnalysis -istage1/ndpFlatten -istage1/iface -istage1/cmm -Wall -fno-warn-name-shadowing -fno-warn-orphans -Istage1 -DOMIT_NATIVE_CODEGEN -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -Iparser -package unix -ignore-package lang -recomp -Rghc-timing -H16M '-#include "cutils.h"' -DUSING_COMPAT -i../compat -ignore-package Cabal -c main/Constants.lhs -o stage1/main/Constants.o -ohi stage1/main/Constants.hi ./../includes/GHCConstants.h:1:25: Not in scope: `zd' ./../includes/GHCConstants.h:2:25: Not in scope: `zd' [...alot of these here...] <<ghc: 33215112 bytes, 8 GCs, 1582480/3066808 avg/max bytes residency (2 samples), 17M in use, 0.00 INIT (0.00 elapsed), 0.35 MUT (0.51 elapsed), 0.15 GC (0.16 elapsed) :ghc>> gmake[1]: *** [stage1/main/Constants.o] Error 1 gmake: *** [stage1] Error 1 ---------- errors end ---------- I also noticed that the GHC bundle also tries to install its own gmp even though I explicitly say not to. Why is gmp even bundled with ghc? Anyway hope someone can give me a few pointers on what is going on. yours, /robert -- Systems Administrator & IT-Coordinator Swedish National Graduate School of Language Technology Nordic Graduate School of Language Technology

2 1

-- help needed in packaging ghc-6.8.1
by Andrea Rossato 11 Nov '07

11 Nov '07

Hi! I'm trying to maintain a Haskell tool chain for the Slackware GNU/Linux distribution,[1] which is lacking any Haskell support. The problem is that I'm having some issue in getting the documentation properly built. I must confess I'm not quite familiar with GNU autoconf so please pardon me if some of the issues I'm going to describe are not ghc specific. Still I hope to have your help in solving part of these problems. Very schematically: 1. the DocBook XSL StyleSheets (probably autoconf related): Slackware installs them in /usr/share/xml/docbook/xsl-stylesheets*, but the configuration script is looking in so many different locations but that one,[2] which seems to me quite appropriate, actually; I solved by making a symbolic link so that /usr/share/sgml/docbook/xsl-stylesheets points to the /usr/share/xml location, but this is far from being a nice solution. I think that /usr/share/xml/docbook/xsl-stylesheets* should be tried to, definitely before trying /usr/share/xml/docbook/stylesheet/nwalsh/current (why should I install a package in a directory named after its author??); 2. "make html" fails for libraries.[3] A work around is to build the library documentation with: ( cd libraries ; make doc ) but I'm not so sure this workaround actually works (see below); 3. documentation is now installed in $PREFIX/share/doc/ghc. Previously documentation was installed in $PREFIX/share/doc/ghc-$VERSION. I don't know if this is the problem, but when build the haddock documentation for libraries, I keep getting: Warning: The documentation for package [put a name here] is not installed. No links to it will be generated. No link is indeed generated, which makes the documentation quite useless (in comparison with what it should be, obviously); 4. Cabal user_guide: I cannot build it, no matter what I try. How should I do? 5. Indexes and links of the produced documentation are wrong or missing (probably because the "make html" target fails?). I downloaded the precompiled binaries and I noticed that that documentation is lacking links and indexes too. Which makes me think this was probably a design decision (a very bad one, I would add if I were sure it was actually planned). Obviously documentation is crucial and if I do not solve these problems I will not able to distribute the package. Unfortunately I've already lost quite a lot of time in trying to solve those issues, and the building guide has not been of any help.[4] The release notes don't say anything about those changes, which are, as far as I understand, totally undocumented. Which is quite bad, I would say. But I could be wrong on that and some documentation may be indeed available. In this case could you point me there, please? Thanks for your kind attention and sorry for such a long message. Regards, Andrea [1] http://gorgias.mine.nu/slack/haskell/ [2] This is the searched path: /usr/share/xml/docbook/stylesheet/nwalsh/current /usr/share/xml/docbook/stylesheet/nwalsh /usr/share/sgml/docbook/docbook-xsl-stylesheets* /usr/share/sgml/docbook/xsl-stylesheets* /opt/kde?/share/apps/ksgmltools2/docbook/xsl /usr/share/docbook-xsl /usr/share/sgml/docbkxsl /usr/local/share/xsl/docbook /sw/share/xml/xs\ l/docbook-xsl /opt/local/share/xsl/docbook-xsl [3] this is the error message: == make html -r; in /tmp/ghc-6.8.1/libraries ------------------------------------------------------------------------ make[1]: *** No rule to make target `html'. Stop. Failed making html in libraries: 1 make: *** [html] Error 1 [4] http://hackage.haskell.org/trac/ghc/wiki/Building/Docs

3 4

Missing _environ while compiling 6.8.1 on Leopard
by Joel Reymont 10 Nov '07

10 Nov '07

Folks, I keep getting this issue when compiling ghc 6.8.1 on Leopard. Manuel doesn't have this issue for some reason. I have removed the GMP framework as per his suggestion but it didn't help. Any clues? --- GHCi, version 6.8.1: http://www.haskell.org/ghc/ :? for help ghc-6.8.1: /usr/local/lib/ghc-6.8.1/lib/base-3.0.0.0/HSbase-3.0.0.0.o: unknown symbol `_environ' Loading package base ... linking ... ghc-6.8.1: unable to load package `base' --- Thanks, Joel -- http://wagerlabs.com

2 2