February 2007 - Yhc - Haskell.org

What constitutes an 'evaluated node'?
by Stefan O'Rear 06 Mar '07

06 Mar '07

Hello. I am writing my own Yhi-Bytecode backend. I wish to minimize the number of indirection checks, and the bytecode.xml is not clear on the subject. Some of the bytecodes, eg INT_SWITCH, require the node they are applied to, to be 'evaluated'. EVAL takes a node and returns an equivalent evaluated node. However in the current implementation (Yhi) EVAL has the side-effect of making any other reference to the original node become evaluated. For instance, this is "legal": not: PUSH_ARG_0 EVAL POP_1 PUSH_ZAP_ARG_0 JUMP_FALSE L2 POP_1 PUSH_CON_0 RETURN L2: POP_1 PUSH_CON_1 RETURN { Prelude.False, Prelude.True } Specifically, I have in mind an implementation where indirections are NEVER automatically followed, and only EVAL and RETURN_EVAL (and for efficiency perhaps APPLY) check for them, returning the targets as the evaluated nodes. Thus in the above example, the value pushed by PUSH_ZAP_ARG_0 would be an indirection node, not False in any case, so our 'not' would mis-behave as 'const False'. Does any yhc generated code rely on this (mis?) feature? Does anyone (note that I do NOT say 'else') think this is a misfeature? Stefan

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Problems installing YHC on Windows XP
by Bryan Burgers 03 Mar '07

03 Mar '07

Hello, I'm interested in fiddling with YHC, maybe helping out from time to time whenever I get free time, so I tried to install it from darcs today. Everything went well (got the source from darcs, downloaded SCons) until I did the configure script (error below). The scons output tells me that it can't find a C compiler. I have one on this computer via MinGW (which has executables named "gcc.exe" and "cpp.exe"). Not knowing SCons, I still took a shot in the dark at the configure script, changing the 'env' line to: env = Environment(ENV=os.environ, CPPPATH=["#.", "C:\\MinGW\\bin\\"]) but that didn't work, either. Should I go with an entirely different compiler? I don't remember why I installed that one, but I'm not sure I even used it, so I'm not even sure if it works. I guess I'm mostly appealing to the last line of the output below, "If so then please contact the Yhc developers for help." (smile) Any help would be appreciated! Bryan Burgers D:\My Documents\My Programs\Languages\Haskell\YHC\yhc>"C:\Program Files\Scons\Scons.py" core=2 scons: Reading SConscript files ... Building version 0.7.0-20070224211823-custom. Checking for architecture... Windows implies x86 Checking for operating system... win32 Checking for Subversion binary... Not found Error. 'svn' not found in PATH. Will use ctypes snapshot. Checking for GHC binary... "ghc" Checking for GHC version 6.4.1 or later... Found version 6.4.2. Checking for Python version 2.3 or later... Found version 2.4.3 final (0). Checking for Scons binary... Not found Checking for Darcs binary... "darcs" Checking for Darcs version... Found version 1.0.7 (release). Checking for Haddock binary... Not found Error. Haddock not found, you won't be able to build the documentation. Checking whether byte ordering is bigendian... failed Checking size of char... failed Checking size of short... failed Checking size of int... failed Checking size of long... failed Checking size of long long... failed Checking size of float... failed Checking size of double... failed Checking size of void*... failed Failed to check types sizes/endianness. You do have a working C compiler don't you? If so then please contact the Yhc developers for help.

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Core
by Ricky Barefield 01 Mar '07

01 Mar '07

Hi, I'm currently working on a project to convert Haskell to Java preserving lazy evaluation and such at Sheffield University. Neil Mitchell suggested that I look into using YHC Core as an intermediary language. It looks ideal, although I am having a couple of problems using it. Firstly so I can work with it I need to use the `Core' data type which seems to be in `Yhc.Core', I realised this isn't part of the windows snapshot of YHC so I found the files within http://darcs.haskell.org/yhc I've downloaded these files and put them into YHC's library folders. The problem is I'm not able to import these files into any of my own code as I get an error message. Would anyone know if I'm doing something wrong? (Let me know if I can tell you a bit more about what I've done) Or have I not downloaded the correct versions of these files? I understand YHC is still being developed, is there a stable version I could use for these files? Many Thanks and any help will be much appreciated. Ricky Barefield -----Original Message----- From: Neil Mitchell [mailto:ndmitchell@gmail.com] Sent: 06 February 2007 19:22 To: Ricky Barefield Subject: Re: [Haskell-cafe] External Core Hi If you do have any questions either post them to Haskell-cafe or yhc(a)haskell.org and I'm sure we'll be able to get you sorted. If there is any documentation you need, and can't find, also just shout and we'll find someone to write it. Thanks Neil On 2/6/07, Ricky Barefield <aca03rdb(a)sheffield.ac.uk> wrote: > Thanks for this I'll look into it. > > Ricky > > -----Original Message----- > From: Neil Mitchell [mailto:ndmitchell@gmail.com] > Sent: 06 February 2007 18:47 > To: Ricky Barefield > Cc: haskell-cafe(a)haskell.org > Subject: Re: [Haskell-cafe] External Core > > Hi Ricky, > > > For the last year I've been working on a program to translate between > > Haskell and Java. Originally this was for my third year dissertation > to > > contribute towards my Masters in computer science at Sheffield > University, > > UK. > > > > I have been given the opportunity to continue this project and have > become > > interested in using the Core representation as an intermediary > language. > > You might be interested in Yhc.Core - its like GHC's Core, but is > simpler, untyped and (in my opinion) better supported. > > http://haskell.org/haskellwiki/Yhc/API/Core > > We already have a Haskell -> Javascript convertor written using this, > so your type of application is certainly doable using what we have > already. There are quite a few users of Yhc.Core already, and everyone > has had nice things to say about it :) > > If you have any specific Yhc.Core questions feel free to ask away > > Thanks > > Neil > >

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Re: Issue 130 in project yhc
by Neil Mitchell 28 Feb '07

28 Feb '07

Hi Dons, You need to specify haskell 98 mode, with -98. > yhc -98 Main > Success Underscores and upper/lower case are broken in Haskell, if anyone can tell us what it _should_ do then we're happy to implement it! Ideally a short and comprehensible spec of what we should allow, and what the result should be, to accept the maximum number of programs! You could also add {-# OPTIONS_YHC -98 #-} to the top of the file to get this test working. Thanks Neil On 2/27/07, codesite-noreply(a)google.com <codesite-noreply(a)google.com> wrote: > > Issue 130: Parser error on _1-style identifiers > http://code.google.com/p/yhc/issues/detail?id=130 > > New issue report by dons00: > YHC's parser seems to die on the following (I think) valid Haskell identifiers: > > main = let _1 = 1 in print _1 > > Dies with: > > serenity$ yhc x.hs > Error: /home/dons/src/nobench/spectral/integer/x.hs(1:12-1:11) Found > {-ERROR 1-} but expected one of _in_ ; {-end-of-definition-} prefix _infix_ > _infixr_ _infixl_ <string> <char> <rational> <integer> ~ > > However hugs, ghc, hbc and nhc98 are happy with it: > > serenity$ runhugs +98 x.hs > 1 > > > Issue attributes: > Status: New > Owner: ---- > Labels: Type-Defect Priority-Medium > > -- > You received this message because you are listed in the owner > or CC fields of this issue, or because you starred this issue. > You may adjust your issue notification preferences at: > http://code.google.com/hosting/settings > > --~--~---------~--~----~------------~-------~--~----~ > You received this message because you are subscribed to the Google Groups "yhc-bugtrack" group. > To post to this group, send email to yhc-bugtrack(a)googlegroups.com > To unsubscribe from this group, send email to yhc-bugtrack-unsubscribe(a)googlegroups.com > For more options, visit this group at http://groups.google.com/group/yhc-bugtrack?hl=en > -~----------~----~----~----~------~----~------~--~--- > >

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Re: Yhc port to Mindstorms
by Colin Runciman 28 Feb '07

28 Feb '07

Phil, > I am working with an MSc student, Alexis Morris, to develop a system to > program Mindstorms Nxt in Haskell. One possibility is to use Yhc. Can > you advise on whether this is a good path, and how difficult you think > it might be? Cheers, -- P Matt Naylor was recently acting as teaching assistant on a course using Lego Mindstorms robots and developed a way of programming the robots in Haskell using the Lava library. As it happens Matt is due to give a talk on this topic at our group meeting tomorrow, and I'm sure he'd be happy to send a copy of his slides if these would be of interest. I'm including Matt on the cc-list. Regards Colin R

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yhi error in nobench: wrong output for digits-of-e2
by dons＠cse.unsw.edu.au 26 Feb '07

26 Feb '07

This program in the nobench suite: http://www.cse.unsw.edu.au/~dons/code/nobench/imaginary/digits-of-e2/digits… Generates incorrect output with yhi darcs version: $ yhc digits-of-e2.hs $ yhi Main.hbc 10 "2.88506250" Should be: $ ./digits-of-e2 10 "2.71828182" If it helps narrow things down, nhc98 from darcs produces the correct output here. Cheers, Don

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Present Yhc build complains "yhc: Error: Found file multiple times, YHC.Exception" compiling Exit.hs
by Thorkil Naur 26 Feb '07

26 Feb '07

Hello Yhc'ers, I have just updated (darcs pull'ed) my regular yhc installation, scons fullclean'ed and then scons type=release --config=force'd. This is the result: ... Compiling YHC.Internal ( src/packages/yhc-base-1.0/YHC/Internal.hs ) Copy("inst/lib/yhc/packages/yhc-base/1.0/YHC/Internal.hi", "src/packages/yhc-base-1.0/YHC/Internal.hi") YHC_build(["src/packages/yhc-base-1.0/System/Exit.hbc"], ["src/packages/yhc-base-1.0/System/Exit.hs"]) inst/bin/yhc -core -cpp -c src/packages/yhc-base-1.0/System/Exit.hs yhc: Error: Found file multiple times, YHC.Exception Reason: imported from System.Exit Found in: scons: *** [src/packages/yhc-base-1.0/System/Exit.hbc] Error 1 scons: building terminated because of errors. Interestingly, my buildbot compiles fine. I can, of course, start all over, but perhaps you would like to inject a comment first? And note: The message "Found file multiple times" actually means "Not found", as far as I have been able to tell The wording of this particular message is the subject of a bug report that I was preparing when this other thing hit. Best regards Thorkil

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Re: Issue 122 in project yhc
by Thorkil Naur 24 Feb '07

24 Feb '07

Hello, On Saturday 24 February 2007 19:28, Neil Mitchell wrote: > ... > > I've just added some code so it now reads: > > > > case (local,res) of > > ([x], _) -> return x > > (_, [x]) -> return x > > ([], []) -> raiseError $ ErrorFileNone noErrPos askMsg file rs > > (as, bs) -> > > -- ASSERTION TO DEBUG GHC 6.6 WITHOUT -O CODEGEN ON A MAC! > > assert (not $ null $ as ++ bs) $ > > raiseError $ ErrorFileMany noErrPos askMsg file (map anyOne (as ++ bs)) > > > > That (to me) looks like an assertion that should always be true, but > > which appears at first glance to be being violated by GHC 6.6 on a Mac > > when compiled without -O. Can you try that on your machine, and see if > > it does raise an assertion? If it does, we can then contact the GHC > > developers and let them get a minimal test case :) > ... To clarify: The yhc failure (i.e. erroneously reporting "multiple files found" instead of "no files found") occurs when yhc has been built with "scons build yhc type=release" so that Package.hs is compiled by ghc-6.6 with -O option. If I compile Package.hs without type=release (i.e. "scons build yhc" which then recompiles a lot, (all?) including Package.hs) so that Package.hs and the other .hs files are compiled without ghc-6.6 option -O, then the resulting yhc works, i.e. reports "no files found" as it should. So: Compiled with type=release (and therefore ghc-6.6 -O), yhc fails. And compiled without type=release (and therefore ghc-6.6 without -O) yhc works. And further: I have tried the above on my machine. Unfortunately, the bug (erroneous report) now disappears, i.e. after scons build yhc type=release, yhc correctly reports "not files found". And, if I remove the assert that you have inserted, the bug re-appears, i.e. yhc incorrectly reports "multiple files" when there are, in fact, none. Neat, eh? I am now trying to introduce the assert in Error.hs instead, don't know if this is a good idea. But in any case, I have the additional problem that (according to ghc documentation), -O (which we need to see the error) implies -fignore-asserts. So I am trying now with GHCFLAGS=-fno-ignore-asserts scons ... Best regards Thorkil

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yhc build bug?
by charles blundell 24 Feb '07

24 Feb '07

Hi. Yhc doesn't like being built twice: $ scons configure && scons build # scons install $ scons clean $ scons build ... Checking whether byte ordering is bigendian... (cached) no Checking size of char... (cached) no Checking size of short... (cached) no Checking size of int... (cached) no Checking size of long... (cached) no Checking size of long long... (cached) no Checking size of float... (cached) no Checking size of double... (cached) no Checking size of void*... (cached) no Failed to check types sizes/endianness. You do have a working C compiler don't you? If so then please contact the Yhc developers for help. I had a C compiler a second ago. It seems the scons caching has gone awry: $ rm .sconsign.dblite $ scons build ... builds as usual. Charles.

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buildbot failure in macosx_x86
by andrewjwilkinsonw＠gmail.com 24 Feb '07

24 Feb '07

The Buildbot has detected a new failure of macosx_x86. Full details are available at: http://www.indiegigs.co.uk:8010/macosx_x86/builds/88 Buildbot URL: http://www.indiegigs.co.uk:8010/ Buildslave for this Build: macosxx86 Build Reason: Build Source Stamp: HEAD Blamelist: Neil Mitchell BUILD FAILED: failed Darcs sincerely, -The Buildbot

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