urbit/j/2/roll.c
2014-09-05 13:13:24 -07:00

48 lines
938 B
C

/* j/2/roll.c
**
** This file is in the public domain.
*/
#include "all.h"
/* functions
*/
u3_noun
u3_cqb_roll(u3_noun a,
u3_noun b)
{
if ( 0 == a ) {
return u3k(u3_cr_at(u3_cv_sam_3, b));
}
else if ( u3_no == u3du(a) ) {
return u3_cm_bail(c3__exit);
}
else {
u3_noun gim = u3k(u3h(a));
u3_noun zor = u3k(u3_cr_at(u3_cv_sam_3, b));
u3_noun daz = u3_cn_slam_on(u3k(b), u3nc(gim, zor));
u3_noun vel = u3_ci_molt(u3k(b), u3_cv_sam_3, daz, 0);
if ( u3_none == vel ) {
return u3_cm_bail(c3__exit);
} else {
u3_noun hox = u3_cqb_roll(u3t(a), vel);
u3z(vel);
return hox;
}
}
}
u3_noun
u3_cwb_roll(u3_noun cor)
{
u3_noun a, b;
if ( u3_no == u3_cr_mean(cor, u3_cv_sam_2, &a, u3_cv_sam_3, &b, 0) ) {
return u3_cm_bail(c3__exit);
} else {
return u3_cqb_roll(a, b);
}
}