urbit/jets/z/cons.c
2018-05-05 15:10:34 -07:00

53 lines
1.0 KiB
C

/* j/6/cons.c
**
*/
#include "all.h"
/* functions
*/
u3_noun
u3qz_cons(u3_noun vur,
u3_noun sed)
{
u3_noun p_vur, p_sed;
if ( c3y == u3r_p(vur, 1, &p_vur) &&
c3y == u3r_p(sed, 1, &p_sed) ) {
return u3nt(1,
u3k(p_vur),
u3k(p_sed));
}
else if ( c3y == u3r_p(vur, 0, &p_vur) &&
c3y == u3r_p(sed, 0, &p_sed) &&
!(c3y == u3r_sing(1, p_vur)) &&
!(c3y == u3r_sing(p_vur, p_sed)) &&
(0 == u3r_nord(p_vur, p_sed)) )
{
u3_atom fub = u3qa_div(p_vur, 2);
u3_atom nof = u3qa_div(p_sed, 2);
if ( c3y == u3r_sing(fub, nof) ) {
u3z(nof);
return u3nc(0, fub);
}
else {
u3z(fub);
u3z(nof);
}
}
return u3nc(u3k(vur), u3k(sed));
}
u3_noun
u3wz_cons(u3_noun cor)
{
u3_noun vur, sed;
if ( c3n == u3r_mean(cor, u3x_sam_2, &vur, u3x_sam_3, &sed, 0) ) {
return u3m_bail(c3__fail);
} else {
return u3qz_cons(vur, sed);
}
}