urbit/gen164/1/sub.c

54 lines
976 B
C
Raw Normal View History

2013-09-29 00:21:18 +04:00
/* j/1/sub.c
**
** This file is in the public domain.
*/
#include "all.h"
2014-09-04 07:10:43 +04:00
2013-09-29 00:21:18 +04:00
/* functions
*/
2014-09-04 01:33:18 +04:00
u2_noun
u2_cqa_sub(u2_atom a,
u2_atom b)
2013-09-29 00:21:18 +04:00
{
2014-08-25 10:58:38 +04:00
if ( u2_so(u2_co_is_cat(a)) && u2_so(u2_co_is_cat(b)) ) {
if ( a < b ) {
return u2_cm_error("subtract-underflow");
}
else return (a - b);
}
else {
mpz_t a_mp, b_mp;
u2_cr_mp(a_mp, a);
u2_cr_mp(b_mp, b);
2013-09-29 00:21:18 +04:00
2014-08-25 10:58:38 +04:00
if ( mpz_cmp(a_mp, b_mp) < 0 ) {
mpz_clear(a_mp);
mpz_clear(b_mp);
2013-09-29 00:21:18 +04:00
2014-08-25 10:58:38 +04:00
return u2_cm_error("subtract-underflow");
}
mpz_sub(a_mp, a_mp, b_mp);
2013-09-29 00:21:18 +04:00
mpz_clear(b_mp);
2014-08-25 10:58:38 +04:00
return u2_ci_mp(a_mp);
2013-09-29 00:21:18 +04:00
}
}
2014-09-04 01:33:18 +04:00
u2_noun
2014-09-03 09:46:55 +04:00
u2_cwa_sub(
2014-09-04 01:33:18 +04:00
u2_noun cor)
2013-09-29 00:21:18 +04:00
{
u2_noun a, b;
2014-08-20 01:49:16 +04:00
if ( (u2_no == u2_cr_mean(cor, u2_cv_sam_2, &a, u2_cv_sam_3, &b, 0)) ||
(u2_no == u2ud(a)) ||
(u2_no == u2ud(b)) )
2013-09-29 00:21:18 +04:00
{
2014-08-20 01:49:16 +04:00
return u2_cm_bail(c3__exit);
2013-09-29 00:21:18 +04:00
} else {
2014-09-03 07:36:29 +04:00
return u2_cqa_sub(a, b);
2013-09-29 00:21:18 +04:00
}
}