- Yhc - Haskell.org

Yhc: A first impression
by Thorkil Naur 07 Jan '07

07 Jan '07

Hello merry Yhc'ers, Doing my homework for the upcoming Hac07 event, I installed and ran Yhc for the first time over some code that has so far survived both Hugs and GHC. In the spirit of Hac07, I downloaded Yhc and built it from the darcs repository, as described on http://haskell.org/haskellwiki/Yhc/Building. All this happened on a PPC Mac OS X 10.4 using a ghc-6.4.1 that I had installed earlier. I also had darcs installed already. Other tools scons, subversion, python24 (and perhaps more? I cannot recall) I took from darwinports. All this with surprisingly few stumbles. But I do have some comments and questions. And understand, please, that the answers may be perfectly obvious. And that none of these items are preventing anything important from happening. Nevertheless, it would help me a lot if some expert would take just a quick look through the list and say something about each. Feel free to simply say "Supply additional information", "Fix the documentation yourself", or "Report a bug" as appropriate. Here is the list: 1. I compile HelloWorld.hs by "yhc HelloWorld" and it works fine. However, in contrast to the description on http://haskell.org/haskellwiki/Yhc/Tutorial, the result is deposited in Main.hbc and Main.hi, so to run it, I must use "yhi Main". "yhi HelloWorld" produces a complaint (ERROR: couldn't find module named 'HelloWorld'). 2. When invoking yhc and also yhi, it seems that I can add a lot of different suffixes to the module name and they are simply ignored. Thus, "yhi Main.xxx" works just as well as "yhi Main". Throwing my input silently away like this seems unfriendly, I would much prefer to get an error message. 3. On http://haskell.org/haskellwiki/Yhc/Options and also in the output from "yhc -?", I find "-d -dst str destination path for generated bytecode files (default=.)". This dosen't seem right: I the cases I have tried, the bytecode was placed in the same directory as the source. And adding "-d something" did not seem to have any effect. 4. I also tried the command line yhe. However, I had to go into yhc/src/interactive and figure out myself how to build it. It hadn't been built as part of the "normal" build process. (I should mention that I am not particularly interested in the GUI yhe and probably don't even have the installments needed to build it.) 5. Getting to some more meaty things, actually compiling some code, I get the message "Error: Context for Prelude.Num needed in left hand pattern at 98:19-98:23." referring to this line in the code: (x,c) = prpExponent (n-1) p In ghci, I find that prpExponent :: (Num b, Integral a) => a -> a -> (a, b) If I add prpExponent :: Integer -> Integer -> (Integer,Int) (I sinfully avoid these type specifications in many cases), the module compiles fine. In another case of this: (p2p1f2,0) = divMod (p2+1) p2p1f1 yhc reports "Error: Context for Prelude.Integral needed in left hand pattern at 88:3-88:12.". For this, ghci reports p2p1f2 :: Integer p2 :: Integer p2p1f1 :: Integer and I can add p2 :: Integer to fix the problem. I have additional examples of this, all of them involving a pair as left hand side, some of them requiring more elaborate (but less obvious) repairs. Any comments? 6. I get the message "Nothing derived for Id 424 at nopos" and similar messages with 424 replaced by other numbers when a number of modules are compiled. The modules seem to compile OK, however. What does this mean? 7. I have only really managed to execute toy programs. For one of my "real" programs (also a toy, but you know what I mean), I get Thorkil-Naurs-Computer:~/tn/test/Yhc/HASKELL1/tn/Haskell/Hugs thorkilnaur$ yhi Primtal ERROR: couldn't find module named '_Builtin' tried: _Builtin.hbc /Users/thorkilnaur/tn/YhcDarcsRepository/yhc/inst/lib/yhc/packages/yhc-base/1.0/_Builtin.hbc Thorkil-Naurs-Computer:~/tn/test/Yhc/HASKELL1/tn/Haskell/Hugs thorkilnaur$ and I cannot figure out how to solve this problem. Other of my programs also complain that '_Builtin' is missing. 8. Compiling another program, I get Thorkil-Naurs-Computer:~/tn/test/Yhc/HASKELL1/tn/Haskell/Hugs thorkilnaur$ yhc -I EuclidNormal FcbMStep yhc: Error: File not found, Time Reason: imported from Main Looked in: /Users/thorkilnaur/tn/test/Yhc/HASKELL1/tn/Haskell/Hugs/ . EuclidNormal /Users/thorkilnaur/tn/YhcDarcsRepository/yhc/inst/lib/yhc/packages/haskell98/1.0 /Users/thorkilnaur/tn/YhcDarcsRepository/yhc/inst/lib/yhc/packages/yhc-base/1.0 Thorkil-Naurs-Computer:~/tn/test/Yhc/HASKELL1/tn/Haskell/Hugs thorkilnaur$ I have done a very superficial investigation and it appears that it is certainly intended that Time should be included in the Yhc install. On the other hand, I cannot off hand find traces in the scons output that something related to Time has been built. I have similar problems with CPUTime. Please direct me. 9. Finally, I get a message "Error: Identifier getArgs used at 67:15-67:21 is not defined." when using that function in a Main module: args<-getArgs Please comment. Please complain if you think that I am wasting your time with trivia. I have been through most of the Wiki pages that I could find that were related to Yhc. I have also looked briefly over the bug list. Many thanks and best regards Thorkil

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Re: Yhc: A first impression
by Christopher Lane Hinson 06 Jan '07

06 Jan '07

> I have done a very superficial investigation and it appears that it is > certainly intended that Time should be included in the Yhc install. On the > other hand, I cannot off hand find traces in the scons output that something > related to Time has been built. I have similar problems with CPUTime. Please > direct me. > > 9. Finally, I get a message "Error: Identifier getArgs used at 67:15-67:21 is > not defined." when using that function in a Main module: > > args<-getArgs I have made some slow progress on adding the base packages to yhc, and I'm still working on this. Someone more familiar with the internals would probably be able to bang it out a lot faster than me, but still, it's being worked on. Just so that people know. --Lane

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buildbot failure in gentoo_amd64
by andrewjwilkinsonw＠gmail.com 04 Jan '07

04 Jan '07

The Buildbot has detected a failed build of gentoo_amd64. Full details are available at: http://www.indiegigs.co.uk:8010/gentoo_amd64/builds/9 Buildbot URL: http://www.indiegigs.co.uk:8010/ Buildslave for this Build: gentooamd64 Build Reason: Build Source Stamp: HEAD Blamelist: Neil Mitchell BUILD FAILED: failed failed slave lost sincerely, -The Buildbot

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Warning, API change in Yhc.Core.FreeVar
by Neil Mitchell 04 Jan '07

04 Jan '07

Hi, I have developed the API using the word Free to mean both Free and Bound. This is not good. As a result I'm going to be changing most of the terminology in the library, and pretty much guarantee to break all the people using this API. I don't think thats many people, in fact it may well just be me, but before breaking API's I thought I'd let everyone know. The patches should be coming along in about half an hour. Thanks Neil

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Yhc.Core format changes
by Neil Mitchell 30 Dec '06

30 Dec '06

Hi all, especially Dimitry, I've had to change the Yhc.Core format, sadly, so all Yhc.Core users will need to: 1) Pull a fresh copy 2) Clear their inst/lib/*.yca files 3) Rebuild yhc The change is minor, but important. This introduces a new form for the Core language, Lambda expressions. They are never used in the generated code by Yhc, and most transformations can successfully ignore them, but certain things require them, and when they do, there is pretty much no way around it. The extra constructor added is: CoreLam [String] CoreExpr Which has identical meaning to the Haskell construct: \arg1 arg2 -> expression Sorry for doing this, I really hope to never break the Core format again. Thanks Neil

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Adding base libraries to yhc
by Christopher Lane Hinson 29 Dec '06

29 Dec '06

I posted on the bug tracker earlier about doing this and now I am actually attempting it. I went to darcs.haskell.org/packages/ and decided arbitrarily to start with Data.Map, which I copied into the packages/ directory in yhc. When I compile it complains about #if preprocessor statements, which enclose GHC specific code and could be commented out but also there is an #include and what looks like a macro that might actually be important. As I understand it the preprocessor is turned off in yhc (thus the error). As far as I can tell nothing else in packages/ uses preprocessor directives. Possibilities: 1) I should enable -cpp specifically for this file or globally for all of yhc, or just for packages/. (I'm not entirely sure how to get scons to do this but I need to take time and read the scons docs.) 2) I should remove and work around the preprocessor directives. If I start making changes how does yhc keep in sync with any changes that are made to the base packages upstream? 3) It doesn't matter. I should do whatever makes me happy. Please advise. Thanks. --Lane (Submitting this a second time because I snagged the moderation filter the first time.)

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New Google Code Features
by Andrew Wilkinson 19 Dec '06

19 Dec '06

> [ reproduced from: http://google-code-updates.blogspot.com/2006/12/happy-holidays-open-source-…] > > > It's the time of year for giving, and thus I have the pleasure of giving you two much-awaited gifts for Google Code's project hosting<http://code.google.com/hosting/>! > *> File Downloads* - this has been the most-requested feature since we launched<http://google-code-updates.blogspot.com/2006/08/project-hosting-r-us.html>project hosting here on Google Code. We knew it would be, but wanted to ship earlier rather than > later. We think you'll like what we did... *one-click downloads* and scriptable uploads, as well as searchable summaries and labels. > *> Wikis* - all projects now have a tightly-integrated wiki appearing under a new *Wiki* tab. The really cool thing here is that the content is stored in your Subversion repository under the > /wiki/ directory. You can edit the pages with your favorite editor and commit them with your favorite Subversion <http://subversion.tigris.org/> client! Additionally, you can add labels and page summaries to > wiki pages for improved searching. > > We hope you will enjoy these new features - let us know<http://groups.google.com/group/google-code-hosting>what you think! > > Note: for an example, check out the GWT downloads<http://code.google.com/p/google-web-toolkit/downloads/list>or the Serf project's status page <http://code.google.com/p/serf/wiki/SerfStatus>. > > >Cheers, > -g Sweet! Andrew

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buildbot failure in linux_ppc
by andrewjwilkinsonw＠gmail.com 16 Dec '06

16 Dec '06

The Buildbot has detected a failed build of linux_ppc. Full details are available at: http://www.indiegigs.co.uk:8010/linux_ppc/builds/4 Buildbot URL: http://www.indiegigs.co.uk:8010/ Buildslave for this Build: linuxppc Build Reason: The web-page 'force build' button was pressed by 'Isaac Dupree': try again after cleanly restarting my computer Build Source Stamp: HEAD Blamelist: BUILD FAILED: failed yhc sincerely, -The Buildbot

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buildbot failure in linux_ppc
by andrewjwilkinsonw＠gmail.com 16 Dec '06

16 Dec '06

The Buildbot has detected a failed build of linux_ppc. Full details are available at: http://www.indiegigs.co.uk:8010/linux_ppc/builds/3 Buildbot URL: http://www.indiegigs.co.uk:8010/ Buildslave for this Build: linuxppc Build Reason: The web-page 'force build' button was pressed by 'Isaac Dupree': try again from flaky computer Build Source Stamp: HEAD Blamelist: BUILD FAILED: failed yhc sincerely, -The Buildbot

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buildbot failure in linux_ppc
by andrewjwilkinsonw＠gmail.com 16 Dec '06

16 Dec '06

The Buildbot has detected a failed build of linux_ppc. Full details are available at: http://www.indiegigs.co.uk:8010/linux_ppc/builds/2 Buildbot URL: http://www.indiegigs.co.uk:8010/ Buildslave for this Build: linuxppc Build Reason: Build Source Stamp: HEAD Blamelist: golubovsky(a)gmail.com BUILD FAILED: failed yhc sincerely, -The Buildbot

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