urbit/j/4/in_tap.c

/* j/4/in_tap.c
**
** This file is in the public domain.
*/
#include "all.h"


/* functions
*/
  static u3_noun
  _tap_in(
          u3_noun a,
          u3_noun b)
  {
    if ( u3_nul == a ) {
      return b;
    } else {
      u3_noun l_a, n_a, r_a;

      if ( (c3n == u3_cr_trel(a, &n_a, &l_a, &r_a)) ) {
        u3z(b);
        return u3_cm_bail(c3__exit);
      } else {
        return _tap_in
          (r_a,
                  u3nc(u3k(n_a),
                               _tap_in(l_a, b)));
      }
    }
  }

  u3_noun
  u3_cqdi_tap(
                       u3_noun a,
                       u3_noun b)
  {
    return _tap_in(a, u3k(b));
  }
  u3_noun
  u3_cwdi_tap(
                      u3_noun cor)
  {
    u3_noun a, b;

    if ( c3n == u3_cr_mean(cor, u3_cv_sam, &b, u3_cv_con_sam, &a, 0) ) {
      return u3_cm_bail(c3__exit);
    } else {
      return u3_cqdi_tap(a, b);
    }
  }
  u3_noun
  u3_ckdi_tap(u3_noun a, u3_noun b)
  {
    u3_weak c = u3_cqdi_tap(a, b);

    u3z(a); u3z(b);
    if ( c3nne == c ) {
      return u3_cm_bail(c3__exit);
    }
    else return c;
  }