>From the archives:
On Wed May 30 19:10:28 EDT 2001, [EMAIL PROTECTED] wrote:
> On Wed May 30 18:57:33 EDT 2001, [EMAIL PROTECTED] wrote:
> > >you can't use typestr anymore. it's a reserved word.
> >
> > But what does it do? I just spent a few minutes looking
> > at the compiler source, and it was not obvious to me.
>
> Typestr was one of the things to come out of Ken's parting
> flurry of activity. Here's the complete documentation as we have
> it from his show-and-tell a couple of days before he left:
>
> #include <u.h>
> #include <libc.h>
>
> typestr struct _cmplx Cmplx;
> struct _cmplx
> {
> double r;
> double i;
> };
> int Zconv(va_list*, Fconv*);
>
> #pragma varargck type "Z" Cmplx
>
> void
> main(void)
> {
> Cmplx a, b;
> int ia[10];
> double d;
>
> fmtinstall('Z', Zconv);
> a = (Cmplx){1, 0};
> b = (Cmplx){0, 1};
>
> a = -((a + b) - (b - a)) + -((a - b) - (b + a));
> print("a = %Z\n", a);
> a += b;
> print("a = %Z\n", a);
>
> if(a == a)
> print("ok\n");
>
> a = (d = a);
> print("d = %g\n", d);
> print("a = %Z\n", a);
>
> a = (Cmplx)1.0;
> print("a = %Z\n", a);
> }
>
> /*
> * print conversion
> */
> int
> Zconv(va_list *arg, Fconv *fp)
> {
> char s[50];
> Cmplx z;
>
> z = va_arg(*arg, Cmplx);
> sprint(s, "(%g %g)", z.r, z.i);
> strconv(s, fp);
> return sizeof(z);
> }
>
> /*
> * operators
> */
> Cmplx
> _cmplx_pos_(Cmplx a)
> {
> Cmplx r;
>
> r.r = +a.r;
> r.i = +a.i;
> return r;
> }
>
> Cmplx
> _cmplx_neg_(Cmplx a)
> {
> Cmplx r;
>
> r.r = -a.r;
> r.i = -a.i;
> return r;
> }
>
> Cmplx
> _cmplx_add_(Cmplx a, Cmplx b)
> {
> Cmplx r;
>
> r.r = a.r + b.r;
> r.i = a.i + b.i;
> return r;
> }
>
> Cmplx
> _cmplx_sub_(Cmplx a, Cmplx b)
> {
> Cmplx r;
>
> r.r = a.r - b.r;
> r.i = a.i - b.i;
> return r;
> }
>
> int
> _cmplx_eq_(Cmplx a, Cmplx b)
> {
> Cmplx r;
>
> return a.r == b.r && a.i == b.i;
> }
>
> /*
> * assignment-op (can be made from assig and op)
> */
> Cmplx
> _cmplx_asadd_(Cmplx *a, Cmplx b)
> {
> *a = *a + b;
> return *a;
> }
>
> Cmplx
> _cmplx_assub_(Cmplx *a, Cmplx b)
> {
> *a = *a - b;
> return *a;
> }
>
> /*
> * conversions
> */
> int
> _cmplx_i_(Cmplx a)
> {
> return sqrt(a.r*a.r + a.i*a.i);
> }
>
> double
> _cmplx_d_(Cmplx a)
> {
> return sqrt(a.r*a.r + a.i*a.i);
> }
>
> Cmplx
> _d_cmplx_(double a)
> {
> Cmplx r;
>
> r.r = a;
> r.i = 0;
> return r;
> }
