[Haskell-cafe] FunPtr error?

[Galchin, Vasili]

oops .. my bad ...

If I change data Sigval = SivalInt Int

to newtype Sigval = SivalInt Int

OR

       data Sigval = SivalPtr (Ptr Char)

    to newtype Sigval = SivalPtr (Ptr Char).


Why should "newtype" instead of a data type allow my test case to build?

Vasili



On Fri, Jun 13, 2008 at 10:59 PM, Galchin, Vasili <vigalchin at gmail.com>
wrote:

> If I change
>
>      data Sigval = SivalInt Int | SivalPtr (Ptr Char)
> to ...
>
>     newtype Sigval = Sivalint Int | SivalPtr (Ptr Char)
>
> then my test case builds and links. ??
>
>
> Regards, Vasili
>
>
>
>
> On Mon, Jun 9, 2008 at 11:01 PM, Galchin, Vasili <vigalchin at gmail.com>
> wrote:
>
>> I have tried various things to no avail ....
>>
>> vigalchin at ubuntu:~/FTP/Haskell/unix-2.2.0.0/tests/timer$ runhaskell
>> Setup.lhs build
>> Preprocessing executables for Test-1.0...
>> Building Test-1.0...
>> [1 of 1] Compiling Main             ( ./timer.hs,
>> dist/build/timer/timer-tmp/Main.o )
>>
>> ./timer.hs:22:0:
>>     Unacceptable argument type in foreign declaration: Sigval
>>     When checking declaration:
>>         foreign import ccall safe "wrapper" mkNotify
>>           :: Notify -> IO (FunPtr Notify)
>>
>> => here is my Sigval def
>>
>> data Sigval = SivalInt Int | SivalPtr (Ptr Char)
>>
>> I did a find/grep for "Unacceptable argument" in the ghc compiler source
>> and assuming no typo I didn't find. ??
>>
>> Thanks.
>>
>> Kind regards, Vasili
>>
>>
>>
>>
>>  On Mon, Jun 9, 2008 at 11:25 PM, Judah Jacobson <
>> judah.jacobson at gmail.com> wrote:
>>
>>> 2008/6/9 Galchin, Vasili <vigalchin at gmail.com>:
>>> > Ryan,
>>> >
>>> >      I tried but the compiler didn't seem to like the keyword "import":
>>> >
>>> > vigalchin at ubuntu:~/FTP/Haskell/unix-2.2.0.0/tests/timer$ runhaskell
>>> > Setup.lhs build
>>> > Preprocessing executables for Test-1.0...
>>> > Building Test-1.0...
>>> > [1 of 1] Compiling Main             ( ./timer.hs,
>>> > dist/build/timer/timer-tmp/Main.o )
>>> >
>>> > ./timer.hs:29:8: parse error on input `import'
>>> >
>>>
>>> Hi Vasili,
>>>
>>> To fix that error, you probably just need to add the line "Extensions:
>>> ForeignFunctionInterface" to the .cabal file.   (That is the
>>> equivalent of calling ghc by itself with the command-line arguments
>>> -fffi or -XForeignFunctionInterface.)
>>>
>>> Hope that helps,
>>> -Judah
>>>
>>
>>
>
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