Re: Interfacing Modula-2 and "C"

[Gaius Mulley]

Michael Riedl <udo-michael.riedl@t-online.de> writes:

> Gaius,
>
> I need a little support.
>
> If I define a procedure, e.g.
>
> PROCEDURE MatrixOperation(VAR A : ARRAY OF ARRAY OF REAL;
>
>                                                 M,N : CARDINAL);
>
> and want to actually implement the routine in "C" without using a
> definition module of the form "DEFINITION MODULE FOR "C" xyz", then I 
> can define the "C" counterpart as
>
> void MatrixOperation(double *A,
>
>                                    unsigned int high2,
>
>                                    unsigned int high1,
>
>                                    unsigned int M,
>
>                                    unsigned int N)
>
> or with
>
> struct MATRIX {
>         double       *Adr;
>         unsigned int  high2;
>         unsigned int  high1;
> };
>
> void MatrixOperation(struct MATRIX A,
>               unsigned int  M, unsigned int N)
>
> Which one is the correct form ? The documentation would indicate the
> struct form, but not 100 % sure. Essential is that I can safely
> evaluate the high value(s) to do some checks.
>
> Thanks in advance
>
> Michael

Hi Michael,

yes the struct form is correct:

void MatrixOperation (struct MATRIX A,
                      unsigned int M, unsigned int N)


struct MATRIX { double *_m2_contents;
                unsigned int _m2_high_1;
                unsigned int _m2_high_2; };

hope this helps,

regards,
Gaius