urbit/jets/b/snag.c
2015-08-28 08:25:37 -05:00

45 lines
722 B
C

/* j/2/snag.c
**
*/
#include "all.h"
/* functions
*/
u3_noun
u3qb_snag(u3_atom a,
u3_noun b)
{
if ( !_(u3a_is_cat(a)) ) {
return u3m_bail(c3__fail);
}
else {
c3_w len_w = a;
while ( len_w ) {
if ( c3n == u3du(b) ) {
return u3m_bail(c3__exit);
}
b = u3t(b);
len_w--;
}
if ( c3n == u3du(b) ) {
return u3m_bail(c3__exit);
}
return u3k(u3h(b));
}
}
u3_noun
u3wb_snag(u3_noun cor)
{
u3_noun a, b;
if ( (c3n == u3r_mean(cor, u3x_sam_2, &a, u3x_sam_3, &b, 0)) ||
(c3n == u3ud(a)) )
{
return u3m_bail(c3__exit);
} else {
return u3qb_snag(a, b);
}
}