- Glasgow-haskell-users

Regexps
by Amanda Clare 11 Jul '01

11 Jul '01

Hi, I'd like to use regular expressions in my code, so I looked at the ghc documentation on this library and it doesn't say much. RegexString looks great but I don't know how to use it. Some examples would be greatly appreciated! Regex itself has even less documentation. From RegexString: "mkRegex makes a regular expression with the default options (multi-line, case-sensitive), whereas mkRegexWithOpts takes the values for these options as parameteres. The syntax of regular expressions is otherwise that of Perl." Then what's wrong with let exp = mkRegex "^class\(\[(.*)\]," in This would be the Perl syntax for the regexp. It says ghc -package text -c -o RegT.o RegT.hs RegT.hs:13: error in character literal I checked and it doesn't like the escaped ( [ and ]. So how do I escape them? The unescaped inner round brackets mean that I want to collect the result of this match, whereas the escaped brackets mean that these are actual characters I want to match. My text to match looks like this: class([1,0,0,0],"METABOLISM"). class([1,1,0,0],"amino-acid metabolism"). class([1,1,1,0],"amino-acid biosynthesis"). Amanda -- Amanda Clare http://users.aber.ac.uk/ajc99/ Tel: +44 (0)1970 621922 Fax: +44 (0)1970 622455 Dept. of Computer Science, University of Wales, Aberystwyth, SY23 3DB

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Trying to build HDIRECT with ghc-5.00.2
by Adrian Hey 11 Jul '01

11 Jul '01

*** ghc Newbie Alert ** I suppose the first question i should ask is will the current version (hdirect 0.17) work with ghc-5.00.2 or am I wasting my time? I've found I have to put '-package lang' in the ghc options to get the installation to to work at all, but it stops eventually complaining about unrecognised flag -K2m (obsolete presumably). Is there a ghc-5.00.2 alternative? At this point I've given up because I don't really understand what I'm doing or what are appropriate settings for all those xyz_HC_OPTS in the makefiles or what else might need changing. Any advice? Thanks -- Adrian Hey

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test, ping
by Richard Uhtenwoldt 11 Jul '01

11 Jul '01

I've got the 'welcome' message: Welcome to the glasgow-haskell-users mailing list! Please save this message for future reference. Thank you. but no post and its been over a month. is the list dead?

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Internet FORUM XXI
by web-forum-xxi＠addr.com 11 Jul '01

11 Jul '01

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Problem with .ghci (fwd)
by Jose Emilio Labra Gayo 10 Jul '01

10 Jul '01

I have been playing (for the first time) with ghci and it seems to work. However, if I write my own ".ghci", I obtain: ... Loading package std ... linking ... done *** WARNING: ./.ghci is writable by someone else, IGNORING! After that, it works, but ignores the options that I have set in .ghci NOTE1: I have built my system 2 times (firstly with ghc-4.08 to obtain ghc-5.02 (non interactive) and secondly, with ghc-5.02 again to obtain the interactive version. NOTE2: The contents of the .ghci file by now are: :set +s Best regards, Jose Labra

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RE: GHC Alpha port?
by Simon Marlow 10 Jul '01

10 Jul '01

Hi Ken, > On 2001-07-05T10:34:27+0100, Simon Marlow wrote: > > This isn't right: you shouldn't set GhcHcOpts in the first > build. In > > the URL you gave, this line was commented out. That's certainly the > > reason for the core dumps. > > Ah! Careless me. Thank you. > > > In GHC 5.00.2, there's an easier way. For the c1 & c2 > builds, you can > > just set > > GhcUnregisterised = YES > > in build.mk, and you can set $long to empty. > > This seems to have worked. By the way, the "old way" (as specified in > the MacOS port readme) does not work with ghc 5 -- I got a seg fault > when running ghc-inplace during the second stage. Hmm, I should really add a section to the building guide on porting and unregisterised compilation. > > When you get around to bootstrapping on the Alpha, I'll > probably need to > > help you some more, because bootstrapping from .hc files is > quite tricky > > on 5.00. > > I'm there! Great, you're in uncharted territory now :-) (no-one has bootstrapped from unregisterised .hc files with 5.00 yet...) > The first obstacle I encountered is that PackedString.raw_s seems to > be mangled incorrectly. Ok, for unregisterised building we need to disable the mangler. You should be able to just compile the .hc files directly using gcc, but you'll need to make sure that -DNO_REGS and -DUSE_MINIINTERPRETER are added to gcc's command line. The relevant makefile code is in fptools/mk/bootstrap.mk - I'm sure you'll be able to modify it to do the right thing. When you've got it working we'll think about how to set up the bootstrapping system so mangling is optional. (if you're wondering why this is harder than it used to be with 4.08, it's because we used to have the "driver" written in Perl, and the driver knew all about compiling .hc files. Now the driver is in Haskell and part of the compiler itself, we have to manage without it during bootstrapping, hence the new bootstrap.mk makefile) Cheers, Simon

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RE: Concurrent Haskell problem/bug
by Simon Marlow 10 Jul '01

10 Jul '01

> I posted this on comp.lang.functional and someone suggested I > try here. > Apologies if it's not on-charter here - any redirections appreciated. > > I'm seeing unexpected behaviour from GHC 5. (unexpected by > me, anyway :) Hi Greg, As it happens I saw your post on comp.lang.functional and we fixed the bug last week :-) (I replied to the newsgroup, but our news is a bit flaky here so you may not have seen it). Yes, you found a genuine bug in take/putMVar that appeared when the semantics of putMVar changed to allow it to block when the MVar is full. To work around the problem, don't rely on this behaviour of putMVar and either use one of the other Concurrent Haskell datatypes (eg. Chan) or use a second MVar to act as a "lock" on the first one. Cheers, Simon

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RE: GHC Alpha port?
by Simon Marlow 10 Jul '01

10 Jul '01

Hi Ken, GhcHcOpts += -H24m -keep-hc-files-too -optc-DNO_REGS -optc-DUSE_MINIINTERPRETER -fno-asm-mangling -funregisterised -fvia-C GhcRtsHcOpts += -optc-DNO_REGS -optc-DUSE_MINIINTERPRETER -fno-asm-mangling -funregisterised -fvia-C SplitObjs = NO This isn't right: you shouldn't set GhcHcOpts in the first build. In the URL you gave, this line was commented out. That's certainly the reason for the core dumps. In GHC 5.00.2, there's an easier way. For the c1 & c2 builds, you can just set GhcUnregisterised = YES in build.mk, and you can set $long to empty. When you get around to bootstrapping on the Alpha, I'll probably need to help you some more, because bootstrapping from .hc files is quite tricky on 5.00. Cheers, Simon

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Concurrent Haskell problem/bug
by Greg Mildenhall 09 Jul '01

09 Jul '01

I posted this on comp.lang.functional and someone suggested I try here. Apologies if it's not on-charter here - any redirections appreciated. I'm seeing unexpected behaviour from GHC 5. (unexpected by me, anyway :) The code which is producing the surprising results is at the bottom, but I'll breifly explain how it is meant to work here: ppm' spawns three threads, and hands them all an MVar. Each thread just puts a True into that MVar and exits. ppm' takes three values in turn from the MVar and makes sure they are all True - if it sees a False value, it stops looking. Once it has assessed whether they have all returned true, it kills all of its child threads before returning the result of the assessment. In this case, where each child returns True, the threads will have already exited, but my understanding is that they are not GCed while ppm' has a reference to their ThreadIds, so ppm' is still allowed to kill them. The ppm' function is "done" 11 times (but some slightly modified versions caused me to need up to a hundred invocations in order to see the problem, so if you don't see the problem on your GHC, try > 11) and each invocation is wrapped up in an unsafePerformIO. (I don't think the unsafePerformIO should be a problem, because there oughtn't be any interaction between the seperate ppm' instances.) Some of these 11 seem to return the expected result, but one of them doesn't. The output is this: --------------------------- (1,True) (2,True) (3,True) (4,True) (5,True) (6,True) (7,True) (8,True) (9,True) (10,True) PPM: no threads to run: infinite loop or deadlock? --------------------------- So there _does_ seem to be a strange interaction between seperate occurrences of ppm'. Can anyone see how that is happening? (of course the other possibility is that I've done something really silly in my code and not noticed, but I'm happy to take suggestions on that front, too. :) If noone here can see what is causing it, is anyone here brave enough to say "this is probably a GHC bug" and recommend how best I report it? Thanks for any insight you can offer me. -Greg Mildenhall

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2 questions regarding ghci and --make
by Jose Emilio Labra Gayo 08 Jul '01

08 Jul '01

I have just built ghc-5.00.2 and I have 2 questions: 1.- What is the option that I have to change to build the system for interactive use? At this moment, when I run "ghci", I obtain $ ghci ghc-5.00.2: not built for interactive use 2.- If I want to have modules in separate directories. How can I tell "--make" to look for them? For example, imagine that I have the following configuration: DirectoryA contains file A.hs DirectoryB contains file B.hs And I have "Main.hs" which imports "A" and "B". Is there a nice way to compile it? Regards, Jose Labra

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