Nick Eby wrote:
> In trying to compile the Random library from the hugs98 distribution
> i got the following error:
> Random.hs:205: parse error on input `::'
> Line 205 reads:
> primitive getRandomSeed :: IO Integer
>
> I don't see a syntactic error in this line.
I do. :-)
> Does ghc have a problem with the 'primitive' declaration? [...]
Exactly. In GHC (and probably already in NHC, too. Malcolm?) you
have to write
foreign import unsafe getRandomSeed :: IO Int
A few remarks:
* `unsafe' is not necessary, but improves performance, telling
GHC that getRandomSeed won't re-enter Haskell-land before it
has finished (less state to save/restore in the RTS).
* You can't return `Integer' in GHC, only `Int'. This is a
deliberate design decision, because only primitive types should
be handled by the FFI. Integers are not primitive at all, see
e.g. libgmp.
* Obvious, but easily forgotten: Don't forget -fglasgow-exts and
link with the object file containing getRandomSeed (which you
probably have to rip off the Hugs98 sources).
Cheers,
Sven
--
Sven Panne Tel.: +49/89/2178-2235
LMU, Institut fuer Informatik FAX : +49/89/2178-2211
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