November 2009 - jhc - Haskell.org

transformers package on JHC
by Henning Thielemann 14 Nov '09

14 Nov '09

For those people who want to use the 'transformers' package on JHC I have made a patch: http://code.haskell.org/~thielema/transformers-jhc.patch I hesitate to push this to the 'transformers' main branch, since it contains only several syntactic replacements like: do ~(a,b) <- act replaced by do ab <- act let (a,b) = ab How about replacing 'mtl' dependency by 'transformers' in JHC's code? This would free us from some functional dependencies and might bring us closer to a JHC compiled JHC.

2 3

bug or feature: generated constraints of derived Show instance
by Henning Thielemann 14 Nov '09

14 Nov '09

With the patch about unqualified methods in instance declarations I can compile most of my xml-basic package. However it stops at data ProcessingInstruction name string = Known [Attr.T name string] | Unknown String deriving (Eq, Ord, Show ) since the Show instance of Attr.T needs an (Name.Attribute name) constraint. JHC does not seem to generate that automatically. GHC does so, but I do not know, whether this is Haskell 98. I can fix this by writing a custom Show instance, but there are more types with that problem. The file is http://code.haskell.org/~thielema/xml-basic/src/Text/XML/Basic/ProcessingIn… and the compiler message is: Typechecking... [1 of 4] Text.XML.Basic.ProcessingInstruction(....................user error ( What: failure Why: Signature too Weak: [Jhc.Show.Show Text.XML.Basic.ProcessingInstruction.v186,Jhc.Show.Show Text.XML.Basic.ProcessingInstruction.v187] does not imply [Text.XML.Basic.Name.Attribute Text.XML.Basic.ProcessingInstruction.v186] Where: on line 11 in <unknown> in the explicitly typed Instance@.iJhc.Show.showsPrec.Text.XML.Basic.ProcessingInstruction.T Text.XML.Basic.ProcessingInstruction.73_d (Text.XML.Basic.ProcessingInstruction.Known Text.XML.Basic.ProcessingInstruction.74_aa) = Jhc.Show.showParen (Text.XML.Basic.ProcessingInstruction.73_d Jhc.Order.>= 10) (Jhc.Show.showString "Known" Jhc.Basics.. Jhc.Show.showChar ' ' Jhc.Basics.. Jhc.Show.showsPrec 10 Text.XML.Basic.ProcessingInstruction.74_aa) Instance@.iJhc.Show.showsPrec.Text.XML.Basic.ProcessingInstruction.T Text.XML.Basic.ProcessingInstruction.75_d (Text.XML.Basic.ProcessingInstruction.Unknown Text.XML.Basic.ProcessingInstruction.76_aa) = Jhc.Show.showParen (Text.XML.Basic.ProcessingInstruction.75_d Jhc.Order.>= 10) (Jhc.Show.showString "Unknown" Jhc.Basics.. Jhc.Show.showChar ' ' Jhc.Basics.. Jhc.Show.showsPrec 10 Text.XML.Basic.ProcessingInstruction.76_aa) {- on line 11 -} Compilation of module: Text.XML.Basic.ProcessingInstruction)

2 1

Re: [Haskell-cafe] Opinion about JHC
by John Meacham 14 Nov '09

14 Nov '09

Hi, I believe this bug has been fixed in the darcs version, at least, it is in my testing. The fix will be in 0.7.3, or you can try the version from the darcs repository directly. Thanks for the bug report! John On Wed, Nov 11, 2009 at 01:36:05PM -0800, Philippos Apolinarius wrote: > Hi, John. > I > am sending you this second email because the first one has a worng paste. However, if I use the right input, I gent the same error. In fact, it gives exactly the same error for any input, right or wrong. > > {- file: tree.hs -} > {- compile: jhc tree.hs -dc -o > jtree } > import System (getArgs) > > import System.IO > > import IO > > > data Op = AND | OR | NOT deriving (Show, Read) > > > > data Tree= L Int | T Op [Tree] deriving (Show, Read) > > > main= do > > putStrLn "Give me a tree:" > > s <- getLine > let xx= read s > putStrLn (show (xx::Tree)) > > > Here is what happens when I try to run it: > > philip@desktop:~/jhctut$ ./jtree > Give me a tree: > T AND [L 1, L 2] > > jtree_code.c:2670: case fell off > Aborted > > It gives the same error for any input: > > philip@desktop:~/jhctut$ ./jtestarbo > Give me a tree: > fdsfkldkl > > jtestarbo_code.c:2670: case fell off > Abortado > > > It seems that the problem is in the Read class, since it works if I use the Show class only: > > import System (getArgs) > > import System.IO > > import IO > > > data Op = AND | OR | NOT deriving (Show, Read) > > > > data Tree= L Int | T Op [Tree] deriving (Show, Read) > > > main= do > > putStrLn "Give me a tree:" > > s <- > getLine > let xx= T AND [L 1, L 2] > putStrLn (show (xx::Tree)) > > I hope you can fix it. > > > > > > --- On Wed, 11/11/09, John Meacham <john(a)repetae.net> wrote: > > From: John Meacham <john(a)repetae.net> > Subject: Re: [Haskell-cafe] Opinion about JHC > To: haskell-cafe(a)haskell.org > Received: Wednesday, November 11, 2009, 1:37 AM > > On Tue, Nov 10, 2009 at 07:41:54PM -0800, Philippos Apolinarius wrote: > > I discovered a Haskell compiler that generates very small and fast > > code. In fact, it beats Clean. It has the following properties: > > Excellent. that was my goal ;) > > > 1 --- One can cross-compile programs easily. For instance, here is how I generated code for Windows: > > > > jhc --cross -mwin32 genetic.hs -o genetic > > Yup. This was a major goal. compiling for iPhones and embedded arches is > just as easy assuming you have a gcc toolchain set up. (at least with > the hacked iPhone SDK.. I have never tried it with the official one) > > > > > 2 -- It seems to be quite complete. > > > > 3 -- However, it often compiles a file, but the program fails to run. > > > > I have the following questions about it: > > > > 1 -- How active is the team who is writing the JHC compiler? > > Hi, I am the main contributor, but others are welcome and several have > made signifigant contributions. Development tends to be spurty. A lot of > work will get done in a short amount of time, this generally corresponds > to when an external contributor gets involved and the back and forth > helps stimulate patches on my part to complement theirs. > > Although I have not been able to devote a lot of my time to jhc in the > past, hopefully this will change in the not to distant future and I will > be able to work on it full time. > > > > 2 -- Is it complete Haskell? The author claims that it is; it compiled > > all programs that I wrote, but that does not mean much, because my > > programs are quite simple. > > It does Haskell 98 and several extensions, which is pretty much what GHC > does. However, it does not implement the same set of extensions as GHC > so this causes issues as a lot of people use GHC extensions extensively. > > I plan on supporting all of Haskell' of course, and the popular GHC > extensions to help compatibility. Not all are implemented. > > > 3 -- Why the Haskell community almost never talks about JHC? > > Part of it is that I am not very good at advocacy. I don't always > post announcements on the main haskell lists figuring the interested > parties are on the jhc list already. I do try to make jhc good, fast, > and usable, I always hoped someone better at advocacy than me would join > the project :) In truth, I think the spurty nature of development also > affects this, the list will be quite for a long time with a flurry of > development lasting a few weeks occasionally inspiring some discussion > in the other groups. > > In any case, I am glad you liked what you found! please join the mailing > list for jhc if you are interested in its development or using it. > > John > > > > -- > John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/ > -- > Haskell-Cafe mailing list > Haskell-Cafe(a)haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > > __________________________________________________________________ > Ask a question on any topic and get answers from real people. Go to Yahoo! Answers and share what you know at http://ca.answers.yahoo.com -- John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/

2 1

Region inference and no GC -- what kinds of programs?
by Jason Dusek 12 Nov '09

12 Nov '09

It's my understanding that, through region inference, JHC is able to generate binaries that are statically allocated. How applicable is this feature to long running server processes? Removal of GC latency can help in maintaining SLAs. I'd like to learn more about this feature of JHC -- how to know if it has been done, how it is triggered and what are some example programs that work with it. -- Jason Dusek

1 0

Multi parameter type classes
by Henning Thielemann 12 Nov '09

12 Nov '09

Is there also anonymous access to the JHC bug+feature-tracker? I like to add a request for multi-type parameter classes. These are necessary to compile NumericPrelude, what most of my signal processing code is based on. I need them for instance for vector spaces in order to write frequency filters and interpolations that work on both mono and stereo signals. I do not need functional dependencies. numericprelude$ grep -rh LANGUAGE src | sort --unique {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE NoImplicitPrelude #-}

2 1

list libraries
by Henning Thielemann 10 Nov '09

10 Nov '09

The output form of --list-libraries has changed from jhc-0.7.2 to the darcs version (0.7.3 pre) which is unfortunate, since I use this option in Cabal to determine installed packages. Both formats contain enough information, but it is cumbersome to handle both of them.

2 1

applicative vs. special-functors
by Henning Thielemann 10 Nov '09

10 Nov '09

It seems that special-functors and applicative serves a similar purpose, namely providing Applicative, Foldable and friends for base-1.0. But they are not exactly the same, since applicative contains Control.Arrow, too. Thus I have to extend all packages that use Applicative by a Cabal switch that include applicative instead of special-functors for JHC. Hm.

1 0

Re: Compiling JHC from Darcs-HEAD
by Henning Thielemann 08 Nov '09

08 Nov '09

On Tue, 3 Nov 2009, John Meacham wrote: > This is probably because you didn't pull the additional Doc repository, > 'make darcs-fetch' should pull it down. Yes this works. I think I have now successfully compiled jhc. However, when calling 'make install' I get parse errors in the containers package. I assumed, that 'make install' would just install files without inspecting them again. make install-am make[1]: Entering directory `/home/thielema/programming/haskell/jhc' ./jhc --noauto -L- -L. -Isrc/data -Ilib/containers/include -ilib/containers -pjhc -pbase -papplicative -fcpp --build-hl lib/containers.cabal -o containers-0.2.0.hl jhc --noauto -L- -L. -Isrc/data -Ilib/containers/include -ilib/containers -pjhc -pbase -papplicative -fcpp --build-hl lib/containers.cabal -o containers-0.2.0.hl jhc 0.7.3 (0.7.2-36) Creating library from description file: "lib/containers.cabal" Reading: "lib/containers.cabal" Finding Dependencies... Using Ho Cache: '/root/.jhc/cache' Data.Graph [lib/containers/Data/Graph.hs] lib/containers/Data/IntSet.hs:168 - Warning: The pragma 'UNPACK' is unknown lib/containers/Data/IntSet.hs:169 - Warning: The pragma 'UNPACK' is unknown lib/containers/Data/IntSet.hs:169 - Warning: The pragma 'UNPACK' is unknown lib/containers/Data/IntSet.hs:722 - Warning: The pragma 'UNPACK' is unknown Data.IntSet [lib/containers/Data/IntSet.hs] Data.Tree [lib/containers/Data/Tree.hs] lib/containers/Data/Sequence.hs:312:16: Parse error make[1]: *** [containers-0.2.0.hl] Fehler 1 make[1]: Leaving directory `/home/thielema/programming/haskell/jhc' make: *** [install] Fehler 2 Parse error occurs in a SPECIALIZE INLINE pragma. If I remove that, I get errors about INLINE pragma with 'instance' and so on ...

2 1

darcs patch: include errno.h in generated files to get around bug
by John Meacham 05 Nov '09

05 Nov '09

Wed Nov 4 20:16:51 PST 2009 John Meacham <john(a)repetae.net> * include errno.h in generated files to get around bug

1 0

darcs patch: bug update
by John Meacham 05 Nov '09

05 Nov '09

Wed Nov 4 20:14:51 PST 2009 John Meacham <john(a)repetae.net> * bug update

1 0