- Glasgow-haskell-users

Telling ghc where to start
by George Russell 28 Sep '01

28 Sep '01

There are various reasons why one might have a Haskell file which doesn't have the expected "Module.hs" filename, in particular when putting ghc into some larger system which does its own thing with files. I may well want this as part of UniForM in the next few months. However ghc doesn't provide anyway support for this, and while you could create a symbolic link with a name ghc approves of to the real file, that seems somewhat messy. gcc has an option which allows you to specify that the input is, say, a C program (even though it's called "hello.txt") but it's rather messy and might take too long to implement. I suggest instead a new option called -virtual-name or something similar, so that ghc -virtual-name Module.hs /blah/horrible932 will compile the contents of /blah/horrible932, but treat it as if it were called "Module.hs".

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Happy 1.11 InstallShield released
by Reuben Thomas 28 Sep '01

28 Sep '01

A Happy 1.11 InstallShield is now available (including the post hoc bug fix!). -- http://sc3d.org/rrt/ | competent, a. underpromoted

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RE: Non blocking versions of hGetBuf and hPutBuf
by Simon Marlow 28 Sep '01

28 Sep '01

> Are they removed in GHC-5.02? Yes, I'm afraid so. I can implement them again for the new I/O library if necessary, but would it be possible for you to use the Posix library instead? Cheers, Simon

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Why have file names with 3 components?
by George Russell 28 Sep '01

28 Sep '01

This looks like a bug, but please don't change it! If you have a file A.blah.hs containing a module A, ghc5.02 compiles it, producing A.hi and A.blah.o. I have an application for this, since I have just, for the first time, been reluctantly compelled to introduce recursive modules. Rather than writing .hi-boot files (which might have to be rewritten for ghc5.03) I have instead written .boot.hs files, which yield .hi files, which then get moved to .hi-boot. Thus a module A has two sources, the real source A.hs, but also the source for the .hi-boot file, A.boot.hs.

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Non blocking versions of hGetBuf and hPutBuf
by Koen Claessen 28 Sep '01

28 Sep '01

Are they removed in GHC-5.02? /Koen

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Re: Exporting a String
by Marcin 'Qrczak' Kowalczyk 28 Sep '01

28 Sep '01

Fri, 28 Sep 2001 08:20:08 +0200, Sven Eric Panitz <sep(a)softwareag.com> pisze: > xs <- peekCString cxs > ys <- peekCString cys > erg <- return (xs++ys) The last line can be written: let erg = xs++ys and you can also directly write (xs++ys) instead of erg below. > newCString erg All OK, except that you leak memory. This string is allocated using malloc and should be freed using free when no longer needed (either C free or Haskell free). > //calling Haskell function > test=cAppend("the world"," is my oyster"); > > //printing its result > printf("%s\n", test); And then: free(test); BTW, there is less boilerplate (no startupHaskell etc.) when the main program is in Haskell instead of C (of course sometimes this is not what we want). -- __("< Marcin Kowalczyk * qrczak(a)knm.org.pl http://qrczak.ids.net.pl/ \__/ ^^ SYGNATURA ZASTÊPCZA QRCZAK

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More 5.02 downloads
by Reuben Thomas 28 Sep '01

28 Sep '01

I've updated the 5.02 Windows InstallShield, getting rid of one or two teething problems, and improving the availability of the docs. I've also added links to the RedHat 7.1 RPMs and FreeBSD/x86 binary dist. http://www.haskell.org/ghc/download_ghc_502.html is the hot destination. -- http://sc3d.org/rrt/ L'art des vers est de transformer en beautés les faiblesses (Aragon)

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Re: Exporting a String
by Sven Eric Panitz 28 Sep '01

28 Sep '01

I am no expert in these things, but as a matter of fact I just did some quite similar and found the help in the mailing list archive. (at least I did not find a cookbook for this in the documentation) My Haskell module: ================== module Mini where import CString foreign export stdcall cAppend :: CString -> CString -> IO CString cAppend :: CString -> CString -> IO CString cAppend cxs cys = do xs <- peekCString cxs ys <- peekCString cys erg <- return (xs++ys) newCString erg And my C program Main.c calling this function: ============================================== #include <stdio.h> #include "Mini_stub.h" #include "RtsAPI.h" extern void __stginit_Mini ( void ); int main(void) { char* bogusFlags[1] = { "\0" }; char* test; //starting up Haskell runtime startupHaskell(0, bogusFlags, __stginit_Mini); //calling Haskell function test=cAppend("the world"," is my oyster"); //printing its result printf("%s\n", test); //say bye bye to Haskell shutdownHaskell(); return 0; } and my way to build this thing: =============================== ghc -fglasgow-exts -package text -c Mini.hs gcc -I. -I'e:/Program Files/ghc/ghc-5.02/include' -I'E:\Program Files\ghc\ghc-5.02\include\mingw' -c Main.c ghc -fglasgow-exts -no-hs-main -package text -static Main.o Mini.o Mini_stub.o -o Test.exe Please some expert correct me, if this is not the right way to do this. Sven Eric -- ______________________________________________________________ Sven Eric Panitz Uhlandstr. 12 D-64297 Darmstadt Software AG sep(a)softwareag.com (+49)6151-92-1426 --- when I cannot sing my heart, I can only speak my mind ---

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RE: Cash Prizes Win!
by Ashley Yakeley 27 Sep '01

27 Sep '01

At 2001-09-27 03:48, Simon Marlow wrote: >I could turn on subscriber-only posting if there's a consensus to do >that. I vote for that. >It might be inconvenient in that you have to post from the same >account that you read Haskell mail from though, and I know some people >have separate email accounts just for receiving Haskell mail. I also run an email list using Mailman. Anytime a subscriber sends a message from a 'wrong' address, Mailman catches it, and I simply subscribe that address 'nomail', and approve the message. >Also, what do people think about the volume of Conference-related >announcements sent to the list (haskell(a)haskell.org in particular)? I'm not really bothered by the way it is... -- Ashley Yakeley, Seattle WA

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Exporting a String
by Juan Ignacio García García 27 Sep '01

27 Sep '01

hello, Is there any way to export a value of type String? I have tried it as follows Haskell code foreign export f::Int -> IO (StablePtr String) f:: Int -> IO (StablePtr String) f n = newStablePtr ("hola") C code char *cad; cad=f(5); printf("%s",cad); but it does not go (segmentation fault). Thanks in advance, J. Ignacio García

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