IM2_RingElement_term()

const RingElement * IM2_RingElement_term	(	const Ring *	R,
		const RingElement *	a,
		const EngineMonomial *	m )

Definition at line 529 of file ringelement.cpp.

{
  try {
    const PolynomialRing *P = R->cast_to_PolynomialRing();
    if (P != nullptr)
      {
        int nvars0 = P->n_vars();
        const PolynomialRing *K = a->get_ring()->cast_to_PolynomialRing();
        if (K != nullptr && K != P->getCoefficients()) nvars0 -= K->n_vars();
        exponents_t exp = newarray_atomic(int, nvars0);
        varpower::to_expvector(nvars0, m->ints(), exp);
        ring_elem val = P->make_logical_term(a->get_ring(), a->get_value(), exp);
        return RingElement::make_raw(R,val);
      }
    auto Q = dynamic_cast<const M2FreeAlgebraOrQuotient *>(R);
    if (Q != nullptr)
      {
        if (Q->coefficientRing() != a->get_ring())
          {
            ERROR("wrong coefficient ring");
            return nullptr;
          }
        return RingElement::make_raw(Q,
                                     Q->makeTerm(a->get_value(),
                                                 m->ints()));
      }
    ERROR("requires a polynomial ring");
    return nullptr;
  }
  catch (exc::engine_error& e) {
    ERROR(e.what());
    return nullptr;
  }
}

References Ring::cast_to_PolynomialRing(), ERROR, RingElement::get_ring(), RingElement::get_value(), PolynomialRing::getCoefficients(), EngineMonomial::ints(), PolynomialRing::make_logical_term(), RingElement::make_raw(), PolynomialRing::n_vars(), newarray_atomic, and ExponentList< int, true >::to_expvector().