On Fri, May 30, 2008 at 2:12 AM, Jonathan Cast <jonathanccast@fastmail.fm> wrote:

On 29 May 2008, at 11:46 PM, Galchin, Vasili wrote:

Hello,

I don't want to write kludgy Haskell code!

typedef struct blah
{
int val1;

union {

int val2;

struct {

int val3;

int val4;
}
}
} C_type;

question: in Haskell, can I embed definition of the "union" inside of the C typedef, i.e. recursion definition? Or must I have a separate definition for the "union" which I "instantiate" inside the Haskell "typedef", i.e. Haskell "data"?

Assuming all of these are semantic, you can say

newtype HS_type = HS_type (Int, Either Int (Int, Int))

But you lose named fields.

It's hard to give other advice without some idea of /why/ you want to do something like this.

jcc