April 2001 - Glasgow-haskell-users

-make
by S.D.Mechveliani 25 Apr '01

25 Apr '01

Hello, I have two questions on ghc-5.00 -make. The User's Guide says in Section 4.5 that it is simpler to use -make than the Makefile technique. 1. I try ghc -make Main.hs with Main.hs containing main = putStr "hello\n" (in ghc-5.00, binary, i386-unknown, Linux), and it reports ghc-5.00: unrecognised flag: -make - ? 2. How to simplify (eliminate?) Makefile. ----------------------------------------- My project has many .hs files in the directories ./source/ ./source/auxil/ ./source/pol/factor/ ... `make ...' compiles them putting .hi, .o files into ./export/, then, applies `ar' to make .a library. To do all this, Makefile includes the rules like .hs.o: $(HC) -c $< $(HCFlags) and applies the compiler $(HC) with the flags ... -syslib data -recomp ... -i$(E) -odir $(E) -ohi $(E)/$(notdir $*).hi $($*_flags) ... Now, this Makefile does not work under ghc-5.00, because second compilation cannot find .hi file of the first compilation: ..ghc -c source/auxil/Prelude_.hs -fglasgow-exts ... -recomp -iexport -odir export -ohi export/Prelude_.hi +RTS -G3 -F1.5 -M29m -RTS -Onot ... ..ghc -c source/parse/Iparse_.hs -fglasgow-exts ... -recomp -iexport -odir export -ohi export/Iparse_.hi +RTS -G3 -F1.5 -M29m -RTS -Onot source/parse/Iparse_.hs:20: failed to load interface for `Prelude_': Bad interface file: export/Iparse_.hi does not exist Also what -make can do to replace some large part of Makefile. For (a) Makefile has rather odd language, it is not good to force the functional programmer to look into it, (b) one has to think of Makefile versions for different operation systems. Thank you in advance for the help. ----------------- Serge Mechveliani mechvel(a)botik.ru

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HINSTANCE from main()
by vince koch 24 Apr '01

24 Apr '01

Axel - While browising FAQs and message boards I found a question you had posted a few months ago. I decided to write you in case you had not learned the answer yet. (I remember this answer was pretty tough to find when I needed it!) =========================================================================== Hi all, I tried to write a Win32 program in with GHC 4.05 but I am stumbeling over the definition type WNDCLASS = (ClassStyle, -- style HINSTANCE, -- hInstance MbHICON, -- hIcon MbHCURSOR, -- hCursor MbHBRUSH, -- hbrBackground MbLPCSTR, -- lpszMenuName ClassName) -- lpszClassName which looks fine if I'd knew where to get hInstance. main doesn't give it to me. Can specify something like winMain hInstance ... = as my main program entry? Or a more sensible question: Is there any userguide on how to use the Win32 library? Cheers, Axel. =========================================================================== You can get a handle to the current instance of your app in one of 2 ways that I am aware of... 1) You can replace your main() with WinMain (defined below) in which case windows will pass you the instance, and you can either pass it into other functions or use it directly int WINAPI WinMain( HINSTANCE hInstance, // handle to current instance HINSTANCE hPrevInstance, // handle to previous instance LPSTR lpCmdLine, // pointer to command line int nCmdShow // show state of window ); OR 2) you can call GetModuleHandle (defined below) and pass in NULL for the lpModuleName and cast the resulting HMODULE into a HINSTANCE as shown below HMODULE GetModuleHandle( LPCTSTR lpModuleName // address of module name to return handle for ); To Use: HINSTANCE hInstance = (HINSTANCE)GetModuleHandle(NULL); Good luck! Vince

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[ghci] Comparison with Hugs
by Volker Stolz 24 Apr '01

24 Apr '01

In Hugs I can throw some definitions into a file and load it on the shell command line or using ":l" in Hugs. ghci however will complain that "main" is missing and even won't keep the defined functions in scope. Is there anything I can do about that? It even doesn't invoke main if it's present. I could hack ghci do add "main = print 1" in case main is undefined, but that's not really something I'd like to admit afterwards... -- Abstrakte Syntaxträume. Volker Stolz * stolz(a)i2.informatik.rwth-aachen.de * PGP + S/MIME

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RE: -optCrts-M28m
by Julian Seward (Intl Vendor) 24 Apr '01

24 Apr '01

| 2. I applied -optCrts-G3 -optCrts-F1.5 -optCrts-M28m | | to compile certain large module on 32Mb RAM machine. | Now, what to apply for this with ghc-5.00 ? +RTS -G3 -F1.5 -M28m -RTS J

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Why does --make only allow one module?
by George Russell 24 Apr '01

24 Apr '01

ghc --make would be wonderful for UniForM, which at the moment consists of a large selection of libraries, were it not for the restriction that ghc --make insists on only having one module as an argument. Er why? At this rate I shall be driven to writing an otherwise useless module which imports all the modules in each directory, since ghc --make does indeed look a lot faster than compiling each module individually. (In particular, we win big here, I think because the NFS system is very inefficient and makes reading all the .hi files very expensive.) Actually I'd like to just give ghc --make a list of ALL the source files and let it figure out the dependencies. This could also include object files (compiled from C) which were to be linked in, for example.

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-optCrts-M28m
by S.D.Mechveliani 24 Apr '01

24 Apr '01

Could ghc-5.00 explain, please, some changes in the compiler and RTS options? 1. -hi-diffs worked in ghc-4.08 and now does not. 2. I applied -optCrts-G3 -optCrts-F1.5 -optCrts-M28m to compile certain large module on 32Mb RAM machine. Now, what to apply for this with ghc-5.00 ? Thank you in advance for the help. ----------------- Serge Mechveliani mechvel(a)botik.ru

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make maintainer-clean (was: Re: The (Interactive) Glasgow Haskell Compiler -- version 5.00)
by Michael Weber 23 Apr '01

23 Apr '01

On Mon, Apr 23, 2001 at 15:00:08 +0100, Simon Marlow wrote: > > Mon, 16 Apr 2001 00:15:39 +1000, Manuel M. T. Chakravarty > > <chak(a)cse.unsw.edu.au> pisze: > > > > > The source tar ball misses the configure scripts (it has the > > > `configure.in's, but the source tar ball should be > > > autoconf'ed, shouldn't it?) > > > > BTW, IMHO 'make maintainer-clean' should not delete configure scripts > > (comments say that it doesn't, but it does). > > I dunno. 'make distclean' leaves the configure scripts in place, 'make > maintainer-clean' is supposed to get you back to a pristine tree as it > would be if it were just checked out from CVS. erm, not that I say, sticking to the standards is mandatory, but... ;) $ info standards 'Managing Releases' 'Makefile Conventions' 'Standard Targets' [...] The reason we say "almost everything" is that running the command `make maintainer-clean' should not delete `configure' even if `configure' can be remade using a rule in the Makefile. More generally, `make maintainer-clean' should not delete anything that needs to exist in order to run `configure' and then begin to build the program. This is the only exception; `maintainer-clean' should delete everything else that can be rebuilt. [...] There should be an additional target, e.g. "make cvs-clean", or similar. Cheers, Michael -- /~\ ASCII ribbon | "I would rather spend 10 hours reading someone else's \ / campaign | source code than 10 minutes listening to Musak waiting X against | for technical support which isn't." / \ HTML mail | -- Dr. Greg Wettstein, Roger Maris Cancer Center

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Re: New InstallShield: Free At Last
by John.Velman＠HSC.com 23 Apr '01

23 Apr '01

This sounds good. One question: Can this live gracefully with an already complete Cygwin installation? I.e., will I automatically end up with two versions of bash, mv, cp, and so on, and can they live together? Thanks, John Velman Reuben Thomas <rrt(a)dcs.gla.ac.uk>@haskell.org on 04/23/2001 03:41:12 AM Sent by: glasgow-haskell-users-admin(a)haskell.org To: GHC users mailing list <glasgow-haskell-users(a)haskell.org> cc: Subject: New InstallShield: Free At Last I've uploaded a new InstallShield for GHC 4.08.2 for Windows which includes *all* the programs required to use and even rebuild GHC from source [GHC developers should note that it doesn't include everything needed to build from CVS; see the most recent 5.00 docs in CVS for details]. This means that there's no longer any need to install Cygwin. Since GHC needs bash to work, and building it requires mv, rm and cp, plus many other basic utilities, you get a reasonably nice minimal command-line environment anyway; I've added ls to the mix for extra comfort. Although the InstallShield is now 20M, overall there's far less to download, and now GHC should break far less often. Another implication of this development is that the Windows version of 5.00 should now happen sooner rather than later. One caveat: the installation instructions on haskell.org are now somewhat out of date. I'll try to correct that soonish. -- http://sc3d.org/rrt/ | Si hoc legere scis nimium eruditionis habes. _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users(a)haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

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RE: how to implement timeouts for IO operations?
by Simon Marlow 23 Apr '01

23 Apr '01

The correct way to implement timeout in GHC 5.00 is below. This should really be in a library somewhere. This implementation works for GHC's current "blocking" semantics for throwTo, but if we change the semantics of throwTo to match the asynchronous exceptions paper (http://www.haskell.org/~simonmar/papers/async.ps.gz) then a different implementation of timeout will be needed. Cheers, Simon ------------------------------------------------------------------------ ----- import Dynamic import Unique import Exception import Concurrent data TimeOut = TimeOut Unique timeOutTc = mkTyCon "TimeOut"; instance Typeable TimeOut where { typeOf _ = mkAppTy timeOutTc [] } timeout secs on_timeout action = do { parent <- myThreadId; i <- newUnique; block (do timeout <- forkIO (timeout_thread secs parent i); Exception.catchDyn ( unblock ( do { result <- action; killThread timeout; return result; } ) ) ( \exception -> case exception of TimeOut u | u == i -> unblock on_timeout other -> do { killThread timeout; throwDyn exception } ) ) } timeout_thread secs parent i = do { threadDelay (secs * 1000000); throwTo parent (DynException (toDyn (TimeOut i))) }

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An attempt at foldr/build fusion for zip
by Matt Harden 23 Apr '01

23 Apr '01

Hi, I think I may have found a way to get zip & friends to fuse with *both* of their input lists. I am not a heavy ghc hacker, though, so I may be missing something important that makes this unworkable. I have no idea what kind of code this would actually end up creating. Anyway, here's my attempt; it ties in with the current foldr2 scheme. I eagerly any await comments or questions, especially from the foldr/build gurus. -- foldr2_both.lhs: Attempting to fuse zip with both input lists. We seem to be forced to use a recursive datatype to accomplish this. We're using newtype, so there should be no overhead from construction/deconstruction of this type, right? \begin{code} newtype BuildZip a b = BZ ((a -> (BuildZip a b) -> b) -> b) bz :: (forall b. (a->b->b)->b->b) -> b -> BuildZip a b bz f n = f (\x xs -> BZ (\c -> c x xs)) (BZ (\_ -> n)) {-# INLINE bz #-} foldr2_both :: (a->b->c->c) -> BuildZip a c -> BuildZip b c -> c foldr2_both k (BZ xs) (BZ ys) = xs (\x xs' -> ys (\y ys' -> k x y (foldr2_both k xs' ys') ) ) {-# RULES "foldr2/both" forall k n (f::forall z.(a->z->z)->z->z) (g::forall z.(b->z->z)->z->z) . foldr2 k n (build f) (build g) = foldr2_both k (bz f n) (bz g n) #-} \end{code} -- END foldr2_both.lhs Best regards, Matt Harden

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