/* j/3/swp.c
**
*/
#include "all.h"

/* functions
*/

  u3_noun
  u3qc_swp(u3_atom a,
           u3_atom b)
  {
    //XX write a proper c-style swp, maybe
    return u3kc_rep(u3k(a), u3kb_flop(u3qc_rip(a, b)));
  }

  u3_noun
  u3wc_swp(u3_noun cor)
  {
    u3_noun a, b;

    if ( (c3n == u3r_mean(cor, u3x_sam_2, &a, u3x_sam_3, &b, 0)) ||
         (c3n == u3ud(a)) ||
         (c3n == u3ud(b)) )
    {
      return u3m_bail(c3__exit);
    } else {
      return u3qc_swp(a, b);
    }
  }

  u3_noun
  u3kc_swp(u3_atom a,
           u3_atom b)
  {
    u3_noun res = u3qc_swp(a, b);
    u3z(a); u3z(b);
    return res;
  }