- Glasgow-haskell-users

RE: Default name of target executable
by Simon Marlow 11 Oct '05

11 Oct '05

On 11 October 2005 06:29, Tomasz Zielonka wrote: > On 10/10/05, Simon Marlow <simonmar(a)microsoft.com> wrote: >> There's no really deep reason for this choice, other than it being >> what GHC does normally - i.e. the default binary has always been >> a.out (main.exe on Windows) unless -o is given. >> >> I don't see enough of a compelling reason to change it, sorry. It's >> not broken, just slightly inconvenient. > > It wasn't meant to be a bug report, only a feature request ;-) > > Actually, I was mostly interested if anyone would mind if GHC > chose the name based on the top-level module. > > Would you accept the patch? I'm slightly inclined not to make this change, but I could be swayed if there was enough interest in it. What I'm seeing so far is not overwhelming support for the change. Simon PJ is in favour, though. You can always use Cabal, BTW :) Anyone else? Cheers, Simon

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RE: GADT question
by Simon Peyton-Jones 11 Oct '05

11 Oct '05

I'm afraid that GHC does not treat the interaction of type classes and GADTs properly. Your example shows this up even more starkly than usual: why should the IsZ thing work, but the Div one not work? The right fix is alas not very simple, which is why I have not done it. (It involves what Martin Sulzmann calls "implication constraints".) However, GADTs and type classes ought to be fine together, and the fact that many people have reported bugs suggests that the interaction is useful. I plan to tackle it in the next couple of months. Simon | -----Original Message----- | From: glasgow-haskell-users-bounces(a)haskell.org [mailto:glasgow-haskell-users- | bounces(a)haskell.org] On Behalf Of J. Garrett Morris | Sent: 10 October 2005 18:06 | To: glasgow-haskell-users(a)haskell.org | Subject: GADT question | | Hello, | | I've been attempting to use GADTs to create a small domain specific | language, and I'm running into an odd problem. Adding one case to the | example at the beginning of the Wobbly types paper: | | data Term :: * -> * | where Lit :: a -> Term a | Inc :: Term Int -> Term Int | IsZ :: Num a => Term a -> Term Bool | Div :: Fractional a => Term a -> Term a -> Term a | If :: Term Bool -> Term a -> Term a -> Term a | | and extending the eval function accordingly: | | eval :: Term a -> a | eval (Lit i) = i | eval (Inc t) = eval t + 1 | eval (IsZ t) = eval t == 0 | eval (Div t u) = eval t / eval u | eval (If cond cons alt) = if eval cond then eval cons else eval alt | | I get an error "No instance for (Fractional a) arising from the use of | '/'" This seems odd to me, since Div is constrained to have | fractional arguments. Is there something obvious I'm missing?

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RE: Default name of target executable
by Simon Marlow 11 Oct '05

11 Oct '05

On 11 October 2005 10:04, Christian Maeder wrote: > Simon Marlow wrote: >> You can always use Cabal, BTW :) > > ghc should supply it, too. GHC does come with Cabal. ? Cheers, Simon

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RE: Default name of target executable
by Simon Marlow 11 Oct '05

11 Oct '05

On 11 October 2005 09:58, Ketil Malde wrote: > "Simon Marlow" <simonmar(a)microsoft.com> writes: > >> I'm slightly inclined not to make this change, but I could be swayed >> if there was enough interest in it. What I'm seeing so far is not >> overwhelming support for the change. Simon PJ is in favour, though. > > "a.out" is tradition, of course, but OTOH, I don't think anybody > actually depends on it. Could it perhaps be made optional, either > through a config file (.ghc?) or an environment variable, or some > such? It *is* optional, there's the -o flag! I don't reaaly think we want -no-default-executable-name. Cheers, Simon

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GADT question
by J. Garrett Morris 10 Oct '05

10 Oct '05

Hello, I've been attempting to use GADTs to create a small domain specific language, and I'm running into an odd problem. Adding one case to the example at the beginning of the Wobbly types paper: data Term :: * -> * where Lit :: a -> Term a Inc :: Term Int -> Term Int IsZ :: Num a => Term a -> Term Bool Div :: Fractional a => Term a -> Term a -> Term a If :: Term Bool -> Term a -> Term a -> Term a and extending the eval function accordingly: eval :: Term a -> a eval (Lit i) = i eval (Inc t) = eval t + 1 eval (IsZ t) = eval t == 0 eval (Div t u) = eval t / eval u eval (If cond cons alt) = if eval cond then eval cons else eval alt I get an error "No instance for (Fractional a) arising from the use of '/'" This seems odd to me, since Div is constrained to have fractional arguments. Is there something obvious I'm missing? Thanks, /g

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Map.lookupInsertWithDefault ?
by Serge D. Mechveliani 10 Oct '05

10 Oct '05

I am going to use the function lookupInsertWithDefault :: Ord a => Map.Map a b -> a -> b -> (Map.Map a b, b) lookupInsertWithDefault tab a b' = case Map.lookup a tab of Just b -> (tab, b ) _ -> (Map.insert a b' tab, b') Its intention is as in the example: lookupInsertWithDefault ftable n (factor n) -> (ftable', factorization) (1) I hope that it will search in the table before trying to compute (factor n) by new. Also it stores each new value for future. (2) I wonder in what relation this may be to existing libraries (something like findWithDefault + insert) and whether the Map library may need such. What the people think of this? Regards, ----------------- Serge Mechveliani mechvel(a)botik.ru

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Re: problems building under os x 10.3.9
by Robby Findler 09 Oct '05

09 Oct '05

At Sun, 9 Oct 2005 14:54:42 +0100, Iain Gray wrote: > Robbie, > > I used Wolfgang's site under 10.4.2 and it installed fine. Thanks! Worked great for me too. Robby

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problems building under os x 10.3.9
by Robby Findler 09 Oct '05

09 Oct '05

Hi all, I'm having trouble building ghc under mac os x 10.3.9. I've gotten darwin ports installed and it seems to have build all of ghc's dependencies okay, but when building ghc itself, I get this message: In file included from /tmp/ghc25897.hc:5: /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h: In function `__hsunix_rtldNext': /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h:103: error: `RTLD_NEXT' undeclared (first use in this function) (the full transcript is below). I think that this is also listed as a bug on the opendarwin site, but I couldn't find any fixes there: http://www.opendarwin.org/pipermail/darwinports-bugs/2005-May/010649.html Am I missing something silly? Thanks, Robby % sudo port install ghc ---> Fetching gmake ---> Attempting to fetch make-3.80.tar.gz from ftp://ftp.gnu.org/gnu/make ---> Verifying checksum(s) for gmake ---> Extracting gmake ---> Configuring gmake ---> Building gmake with target all ---> Staging gmake into destroot ---> Packaging tgz archive for gmake 3.80_1 ---> Installing gmake 3.80_1 ---> Activating gmake 3.80_1 ---> Cleaning gmake ---> Fetching gmp ---> Attempting to fetch gmp-4.1.4.tar.bz2 from ftp://ftp.gnu.org/gnu/gmp ---> Verifying checksum(s) for gmp ---> Extracting gmp ---> Configuring gmp ---> Building gmp with target all ---> Staging gmp into destroot ---> Packaging tgz archive for gmp 4.1.4_2+test ---> Installing gmp 4.1.4_2+test ---> Activating gmp 4.1.4_2+test ---> Cleaning gmp ---> Fetching perl5.8 ---> Attempting to fetch perl-5.8.7.tar.bz2 from http://www.cpan.org/src/5.0/ ---> Verifying checksum(s) for perl5.8 ---> Extracting perl5.8 ---> Applying patches to perl5.8 ---> Configuring perl5.8 ---> Building perl5.8 with target all ---> Staging perl5.8 into destroot ---> Packaging tgz archive for perl5.8 5.8.7_0 ---> Installing perl5.8 5.8.7_0 ---> Activating perl5.8 5.8.7_0 ---> Cleaning perl5.8 ---> Fetching readline ---> Attempting to fetch readline50-001 from ftp://ftp.cwru.edu/pub/bash/readline-5.0-patches/ ---> Attempting to fetch readline50-002 from ftp://ftp.cwru.edu/pub/bash/readline-5.0-patches/ ---> Attempting to fetch readline50-003 from ftp://ftp.cwru.edu/pub/bash/readline-5.0-patches/ ---> Attempting to fetch readline50-004 from ftp://ftp.cwru.edu/pub/bash/readline-5.0-patches/ ---> Attempting to fetch readline50-005 from ftp://ftp.cwru.edu/pub/bash/readline-5.0-patches/ ---> Attempting to fetch readline-5.0.tar.gz from ftp://ftp.gnu.org/gnu/readline ---> Verifying checksum(s) for readline ---> Extracting readline ---> Applying patches to readline ---> Configuring readline ---> Building readline with target all ---> Staging readline into destroot ---> Packaging tgz archive for readline 5.0.005_0 ---> Installing readline 5.0.005_0 ---> Activating readline 5.0.005_0 ---> Cleaning readline ---> Fetching ghc ---> Attempting to fetch ghc-6.4.1-src.tar.bz2 from http://www.haskell.org/ghc//dist/6.4.1/ ---> Attempting to fetch happy-1.15-src.tar.gz from http://www.haskell.org/happy/dist/1.15 ---> Attempting to fetch ghc-6.4-darwin-bootstrap-v01.tar.bz2 from http://www.haskell.org/ghc//dist/6.4/MacOSX/ ---> Verifying checksum(s) for ghc ---> Extracting ghc ---> Applying patches to ghc ---> Configuring ghc ---> Building ghc with target all Error: Target com.apple.build returned: shell command "DYLD_FALLBACK_LIBRARY_PATH=/opt/local/lib gmake all" returned error 2 Command output: /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/bin/ghc -H16m -O -I/usr/include -I/opt/local/include -L/usr/lib -L/opt/local/lib -istage1/utils -istage1/basicTypes -istage1/types -istage1/hsSyn -istage1/prelude -istage1/rename -istage1/typecheck -istage1/deSugar -istage1/coreSyn -istage1/specialise -istage1/simplCore -istage1/stranal -istage1/stgSyn -istage1/simplStg -istage1/codeGen -istage1/main -istage1/profiling -istage1/parser -istage1/cprAnalysis -istage1/compMan -istage1/ndpFlatten -istage1/iface -istage1/cmm -istage1/nativeGen -Istage1 -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -package unix -ignore-package lang -recomp -Rghc-timing -H16M '-#include "hschooks.h"' -i../lib/compat -ignore-package Cabal -c basicTypes/OccName.lhs-boot -o stage1/basicTypes/OccName.o-boot -ohi stage1/basicTypes/OccNam e.hi-boot <<ghc: 28651560 bytes, 8 GCs, 2408670/4720920 avg/max bytes residency (2 samples), 18M in use, 0.02 INIT (0.02 elapsed), 0.16 MUT (0.33 elapsed), 0.18 GC (0.21 elapsed) :ghc>> /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/bin/ghc -H16m -O -I/usr/include -I/opt/local/include -L/usr/lib -L/opt/local/lib -istage1/utils -istage1/basicTypes -istage1/types -istage1/hsSyn -istage1/prelude -istage1/rename -istage1/typecheck -istage1/deSugar -istage1/coreSyn -istage1/specialise -istage1/simplCore -istage1/stranal -istage1/stgSyn -istage1/simplStg -istage1/codeGen -istage1/main -istage1/profiling -istage1/parser -istage1/cprAnalysis -istage1/compMan -istage1/ndpFlatten -istage1/iface -istage1/cmm -istage1/nativeGen -Istage1 -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -package unix -ignore-package lang -recomp -Rghc-timing -H16M '-#include "hschooks.h"' -i../lib/compat -ignore-package Cabal -c basicTypes/Module.lhs-boot -o stage1/basicTypes/Module.o-boot -ohi stage1/basicTypes/Module.hi-boot <<ghc: 28651068 bytes, 8 GCs, 2408742/4720920 avg/max bytes residency (2 samples), 18M in use, 0.03 INIT (0.02 elapsed), 0.23 MUT (0.31 elapsed), 0.16 GC (0.21 elapsed) :ghc>> /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/bin/ghc -H16m -O -I/usr/include -I/opt/local/include -L/usr/lib -L/opt/local/lib -istage1/utils -istage1/basicTypes -istage1/types -istage1/hsSyn -istage1/prelude -istage1/rename -istage1/typecheck -istage1/deSugar -istage1/coreSyn -istage1/specialise -istage1/simplCore -istage1/stranal -istage1/stgSyn -istage1/simplStg -istage1/codeGen -istage1/main -istage1/profiling -istage1/parser -istage1/cprAnalysis -istage1/compMan -istage1/ndpFlatten -istage1/iface -istage1/cmm -istage1/nativeGen -Istage1 -cpp -fglasgow-exts -fno-generics -Rghc-timing -I. -IcodeGen -InativeGen -Iparser -package unix -ignore-package lang -recomp -Rghc-timing -H16M '-#include "hschooks.h"' -i../lib/compat -ignore-package Cabal -c utils/PrimPacked.lhs -o stage1/utils/PrimPacked.o -ohi stage1/utils/PrimPacked.hi utils/PrimPacked.lhs:250:0: Warning: foreign declaration uses deprecated non-standard syntax utils/PrimPacked.lhs:254:0: Warning: foreign declaration uses deprecated non-standard syntax utils/PrimPacked.lhs:257:0: Warning: foreign declaration uses deprecated non-standard syntax utils/PrimPacked.lhs:260:0: Warning: foreign declaration uses deprecated non-standard syntax utils/PrimPacked.lhs:263:0: Warning: foreign declaration uses deprecated non-standard syntax In file included from /tmp/ghc25897.hc:5: /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h: In function `__hsunix_rtldNext': /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h:103: error: `RTLD_NEXT' undeclared (first use in this function) /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h:103: error: (Each undeclared identifier is reported only once /opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-bootstrap/lib/ghc-6.4/include/HsUnix.h:103: error: for each function it appears in.) <<ghc: 55189224 bytes, 12 GCs, 3370890/6784664 avg/max bytes residency (3 samples), 17M in use, 0.02 INIT (0.02 elapsed), 0.48 MUT (0.90 elapsed), 0.39 GC (0.47 elapsed) :ghc>> gmake[2]: *** [stage1/utils/PrimPacked.o] Error 1 gmake[1]: *** [all] Error 1 gmake[1]: Leaving directory `/opt/local/var/db/dports/build/file._opt_local_var_db_dports_sources_rsync.rsync.opendarwin.org_dpupdate_dports_lang_ghc/work/ghc-6.4.1/ghc' gmake: *** [build] Error 1

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Re: Simple GADTs Question
by David Menendez 07 Oct '05

07 Oct '05

J. Garrett Morris writes: > Hello, > > I'm attempting to use GADTs for the first time, and I'm running into > an (I think) odd error. My file includes: > > data DFExpr :: * -> * > where Deriv :: (Num t) => t -> Deriv Int (DFExpr t) (DFExpr t) I think you want something like this: Deriv :: Int -> DFExpr t -> DFExpr t -> DFExpr t Ignorning the other clauses, it's equivalent to data DFExpr t = Deriv Int (DFExpr t) (DFExpr t) -- David Menendez <zednenem(a)psualum.com> | "In this house, we obey the laws <http://www.eyrie.org/~zednenem> | of thermodynamics!"

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Simple GADTs Question
by J. Garrett Morris 06 Oct '05

06 Oct '05

Hello, I'm attempting to use GADTs for the first time, and I'm running into an (I think) odd error. My file includes: data DFExpr :: * -> * where Deriv :: (Num t) => t -> Deriv Int (DFExpr t) (DFExpr t) (:+:) :: (Num t) => DFExpr t -> DFExpr t -> DFExpr t -- and so forth, DFFeat :: FExpr t and I'm getting an error "Not in scope: type constructor or class `Deriv'. I've got -fglasgow-exts in the options - what else should I be doing? /g

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