[Haskell-cafe] modelling C in Haskell ..

[Jonathan Cast]

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