Pascal translation

[Jseb]

I am trying to translate a program from Pascal to C. However some statement in pascal confused me and i am not to sure what should I be using instead.

The statement in question is:

case form: typform of
                   scalarfrm:  ();
                   subrangfrm: ( rangtyp: typtabptr;
                                 min,
                                 max: constrec);
                   enumfrm:    ( maxenum: 0 .. 255);
                   arrayfrm:   ( elemtyp,
                                 indxtyp: typtabptr);
                   recordfrm:  ( lastfld: symtabptr;
                                 recvrnt: typtabptr);
                   tagfrm:     ( tagfldp: symtabptr;
                                 fstvarnt: typtabptr);
                   varntfrm:   ( nxtvarnt,
                                 subvarnt: typtabptr;
                                 varntval: constrec);
                   setfrm:     ( seteltyp: typtabptr;
                                 maxelem: integer);
                   filefrm:    ()

Now the main issues is the first line form: typform to me is a structure type but again i am not sure if i should be implementing a union, or a case statement

Thanks

[CommonTater]

That's object oriented programming and you're very unlikely to get it to work in C.

[iMalc]

What we have here is the complex declaration of a type.
It's basically a union, or more specifically it's a sort of typesafe union where the compiler pretends that only certain members exist depending upon the variable that indicates the type held in the union.

You might later use a switch statement where that type is used, but here it's just the type declaration.

[Jseb]

Thanks for the answer. Yeah it is a complex program, i am trying to make a compiler. So just to be clear if understand the best way to define it would be this way?

typedef struct typrec
{
    int size;
    union form
    {
        typform scalarfrm;
        typform subrangfrm;
        typform enumfrm;
        typform arrayfrm;
        typform recordfrm;
        typform tagfrm;
        typform varntfrm;
        typform setfrm;
        typform filefrm;
        
    };
};

where typform is a enum ( i made it actually a typedef enum) this would be the best way to approach it?