RE: passing Strings with FFI
>foreign import "fooble" fooble >fooble :: PackedString -> Int -> IO Int > >type PackedString = ByteArray Int With the code above I'm getting the following error: -- Unacceptable argument type in foreign declaration: PackedString -- When checking declaration: -- foreign import _ccall "fooble" fooble :: PackedString -> Int -> IO Int Is there any option that I must include when I launch ghc (I'm very new to this compiler, as to Haskell)? -- I'm trying with "ghc -c -fglasgow-exts test.hs" Best regards, Corneliu ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC version 5.00.2 is available
"Julian Seward (Intl Vendor)" <[EMAIL PROTECTED]> wrote, >The (Interactive) Glasgow Haskell Compiler -- version 5.00.2 > == > > We are pleased to announce a new patchlevel release of the Glasgow > Haskell Compiler (GHC), version 5.00.2. For your installation pleasure, RPM packages built on RedHat are now available. Binary packages built for RedHat 7.x are at ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386/ghc-5.00.2-1.i386.rpm ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386/ghc-prof-5.00.2-1.i386.rpm and those for RedHat 6.2 are at ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386-rh6.2/ghc-5.00.2-1.i386.rpm ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/i386-rh6.2/ghc-prof-5.00.2-1.i386.rpm The ghc-prof-* packages contain optional libraries for profiling. The packages for 6.2 are courtesy of Tom Moertel. The source rpm used to built the above binaries is at ftp://ftp.cse.unsw.edu.au/pub/users/chak/jibunmaki/src/ghc-5.00.2-1.src.rpm If you build from the source rpm using an older version of GHC, note that you have to build the system twice if you like to use the interactive environment. The second build should use the compiler generated in the first. Manuel ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: passing Strings with FFI
"Julian Seward (Intl Vendor)" <[EMAIL PROTECTED]> wrote,
> | I want to pass a String to a function which is imported from C code:
> | foreign import "pass" prim_pass :: String -> String
> | The declaration above gives me an error from ghc like "String
> | type not
> | supported for imported functions".
> | I thought that String being [Char] should be supported
> | (somehow like a
> | definition with "newtype" keyword).
> | Can you tell me how can I pass strings to and from C code, as
> | simple as
> | possible (I know about HDirect, but I couldn't make it work
> | for me: red-hat
> | 7.1, ghc 5.00)?
>
> First of all, upgrade to 5.00.2, since it is significantly less
> buggy than 5.00.
>
>
> int fooble ( char* str, int n )
> {
>fprintf(stderr, "fooble called: %s %d\n", str, n );
>return 42;
> }
>
>
> import PrelByteArr
> import PrelPack (packString)
>
> foreign import "fooble" fooble
>fooble :: PackedString -> Int -> IO Int
>
> type PackedString = ByteArray Int
>
> main = do n <- fooble (packString "hello, C world") 99
> putStrLn ("Returned value is " ++ show n)
>
> For more examples read the compiler sources, at
> fptools/ghc/compiler/ghci/Linker.lhs.
Actually, the portable way of achieving the same effect with
the new FFI libraries is
import Foreign
import CForeign
foreign import fooble :: CString -> Int -> IO Int
main = withCStringLen "hello, C world" $ \(strPtr, strLen) -> do
n <- fooble strPtr strLen
putStrLn ("Returned value is " ++ show n)
Note that it is not really necessary to pass the length
information explicitly. The CString will be NUL terminated
and so directly usable by C. I just wanted to exactly
imitate the cited example. If you don't need the string
length, the simpler function `withCString' is sufficient.
To marshall a string from C to Haskell land, use the
function `CForeign.peekCString'.
See
http://haskell.cs.yale.edu/ghc/docs/latest/set/sec-foreign.html
http://haskell.cs.yale.edu/ghc/docs/latest/set/sec-cforeign.html
for details.
The principal advantage of using Foreign and CForeign
instead of the Prel* functions is that the former are part
of the Haskell FFI standard that we are working at and so,
for example, are also supported by NHC.
Cheers,
Manuel
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Re: GHC core representation
[This is a reply to Andrew Tolmachs message to the Haskell list about the -fext-core flag] Hi! Some comments on the -fext-core facility. First I just want to say that it's a really cool feature. It made me a lot keener to use GHC for program analysis measurements. First a question which is not really specific to the -fext-core flag (which I expect someone of the GHC-people to answer): * I would like to make GHC generate only the core file and the hi file, nothing more. However, I haven't found a way of making GHC stop after outputting the hi file. Being able to do this is useful in some other cases as well; I sometimes look at the raw core that comes is printed with the -ddump* flags. It is often the case that I don't want anything to be generated then. OK, here are the comments about the new feature: * In the grammar: the productions for the nonterminal Arguments seems to be erronious. When used as they are they cause tons of shift/reduce conflicts. Having the following solves to problem (I think this is what you really meant): Argument arg -> @ aty | aexp * Speaking of arguments, it would be a nice thing if one could get the output in A-normal-form. This is done by GHC anyway when converting to STG and in some cases it would be really useful. * Exactly when in the compilation process does ghc spit out this info (when I use -fext-core that is)? What I am really asking is: which transformations is applied to the core before it is printed? Knowing this is pretty important. Being able to control it would be super, and from the documentation this seems to be a goal. * A minor point: The example in the beginning of section 3.6 seems to be incorrect. It should read: f :: %forall a . a -> BinTree (BinTree a) = \ @a (x::a) -> Leaf @(BinTree a) (Leaf @a x) ¯¯¯ OK, I think that's all for now. I'll probarbly come up with some more questions in a while. Cheers, /Josef ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: GHC version 5.00.2 is available
| > What's new in 5.00.2 | > == | > | [..] | | How about Andrew Tolmach's -fext-core flag? Did it make it | into 5.00.2 or do we have to wait for next official release? No, it didn't. The 5.00.X line exists purely to give (hopefully) increasingly stable renditions of what was released as 5.00, and in particular to fix show-stopping bugs. All new development happens in the CVS "HEAD" branch, which will get snapshotted into 5.02 at some point. J ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: passing Strings with FFI
| I want to pass a String to a function which is imported from C code:
| foreign import "pass" prim_pass :: String -> String
| The declaration above gives me an error from ghc like "String
| type not
| supported for imported functions".
| I thought that String being [Char] should be supported
| (somehow like a
| definition with "newtype" keyword).
| Can you tell me how can I pass strings to and from C code, as
| simple as
| possible (I know about HDirect, but I couldn't make it work
| for me: red-hat
| 7.1, ghc 5.00)?
First of all, upgrade to 5.00.2, since it is significantly less
buggy than 5.00.
int fooble ( char* str, int n )
{
fprintf(stderr, "fooble called: %s %d\n", str, n );
return 42;
}
import PrelByteArr
import PrelPack (packString)
foreign import "fooble" fooble
fooble :: PackedString -> Int -> IO Int
type PackedString = ByteArray Int
main = do n <- fooble (packString "hello, C world") 99
putStrLn ("Returned value is " ++ show n)
For more examples read the compiler sources, at
fptools/ghc/compiler/ghci/Linker.lhs.
J
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passing Strings with FFI
Hello, I want to pass a String to a function which is imported from C code: foreign import "pass" prim_pass :: String -> String The declaration above gives me an error from ghc like "String type not supported for imported functions". I thought that String being [Char] should be supported (somehow like a definition with "newtype" keyword). Can you tell me how can I pass strings to and from C code, as simple as possible (I know about HDirect, but I couldn't make it work for me: red-hat 7.1, ghc 5.00)? Best regards, Corneliu ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: GHC version 5.00.2 is available
On Mon, 18 Jun 2001, Julian Seward (Intl Vendor) wrote: > >The (Interactive) Glasgow Haskell Compiler -- version 5.00.2 > == > [..] > What's new in 5.00.2 > == > [..] How about Andrew Tolmach's -fext-core flag? Did it make it into 5.00.2 or do we have to wait for next official release? /Josef ___ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
