convertToM2()

const RingElement * convertToM2 ( const PolynomialRing * R, CanonicalForm h )

static

Definition at line 214 of file factory.cpp.

{
  // this seems not to handle polynomials with rational coefficients at all!!
  const int n = R->n_vars();
  if (h.inCoeffDomain())
    {
      if (h.inZ())
        {
          mpz_t x = {toInteger(h)};
          ring_elem ret = R->from_int(x);
          mpz_clear(x);
          return RingElement::make_raw(R, ret);
        }
      else if (h.inQ())
        {
          struct enter_factory c;
          __mpq_struct z = {toInteger(h.num()), toInteger(h.den())};
          ring_elem val;
          bool ok = R->from_rational(&z, val);
          if (not ok)
            {
              std::cout << "internal error: unexpected failure to lift "
                           "rational number to ring"
                        << std::endl;
              val = R->from_long(0);
            }
          RingElement *ret = RingElement::make_raw(R, val);
          mpq_clear(&z);
          return ret;
        }
      else if (h.inFF())
        return RingElement::make_raw(R, R->from_long(h.intval()));
      else if (h.inExtension())
        {
          assert(algebraicElement_M2 != NULL);
          ring_elem result = R->from_long(0);
          for (int j = h.taildegree(); j <= h.degree(); j++)
            {
              const RingElement *r = convertToM2(R, h[j]);
              if (error()) return RingElement::make_raw(R, R->one());
              ring_elem r1 = r->get_value();
              ring_elem v = algebraicElement_M2->get_value();
              v = R->power(v, j);
              r1 = R->mult(r1, v);
              R->add_to(result, r1);
            }
          return RingElement::make_raw(R, result);
        }
      else
        {
          ERROR("conversion from factory over unknown type");
          return RingElement::make_raw(R, R->one());
        }
    }
  ring_elem result = R->from_long(0);
  for (int j = h.taildegree(); j <= h.degree(); j++)
    {
      const RingElement *r = convertToM2(R, h[j]);
      if (error()) return RingElement::make_raw(R, R->one());
      ring_elem r1 = r->get_value();
      int var =
#if REVERSE_VARIABLES
          (n - 1) -
#endif
          (h.level() - 1);
      ring_elem v = R->var(var);
      v = R->power(v, j);
      r1 = R->mult(r1, v);
      R->add_to(result, r1);
    }
  return RingElement::make_raw(R, result);
}

References Ring::add_to(), algebraicElement_M2, convertToM2(), ERROR, error(), Ring::from_int(), Ring::from_long(), Ring::from_rational(), RingElement::get_value(), RingElement::make_raw(), Ring::mult(), PolynomialRing::n_vars(), Ring::one(), Ring::power(), result(), toInteger(), PolynomialRing::var(), and x.

Referenced by convertToM2(), displayCF(), rawCharSeries(), rawExtendedGCDRingElement(), rawFactorBase(), rawGCDRingElement(), and rawPseudoRemainder().