ptr_base
symbolic::internal::lag(const ptr_base &p, int l)
{
if (!l) return p;
if (!(p->flag() & HAST)) return p;
unsigned t = p->type();
if (t == VART) return p.get<ex_vart>()->lag(l);
else if (t == VARTIDX) return p.get<ex_vartidx>()->lag(l);
else if (t == EX) return p.get<ex_e>()->lag(l);
else if (t == ADD) {
const num_ex_pair_vec &in = p.get<ex_add>()->get_ops();
num_ex_pair_vec out;
unsigned i, n = in.size();
out.reserve(n);
for (i = 0; i < n; ++i)
out.push_back(std::pair<Number, ptr_base>(in[i].first,
lag(in[i].second, l)));
return mk_add(out);
} else if (t == MUL) {
const num_ex_pair_vec &in = p.get<ex_mul>()->get_ops();
num_ex_pair_vec out;
unsigned i, n = in.size();
out.reserve(n);
for (i = 0; i < n; ++i)
out.push_back(std::pair<Number, ptr_base>(in[i].first,
lag(in[i].second, l)));
return mk_mul(out);
} else if (t == POW) {
const ex_pow *pt = p.get<ex_pow>();
return mk_pow(lag(pt->get_base(), l), lag(pt->get_exp(), l));
} else if (t == FUN) {
const ex_func *pt = p.get<ex_func>();
return mk_func(pt->get_code(), lag(pt->get_arg(), l));
} else if (t == IDX) {
const ex_idx *pt = p.get<ex_idx>();
return ex_idx::create(pt->get_ie(), lag(pt->get_e(), l));
} else if (t == SUM) {
const ex_sum *pt = p.get<ex_sum>();
return ex_sum::create(pt->get_ie(), lag(pt->get_e(), l));
} else if (t == PROD) {
const ex_prod *pt = p.get<ex_prod>();
return ex_prod::create(pt->get_ie(), lag(pt->get_e(), l));
} else INTERNAL_ERROR
}
ex_e::ex_e(const ptr_base &e, int l)
: ex_base(EX | HAST | (e->flag() & HASIDX)), m_arg(e), m_lag(l)
{
}
ex_func::ex_func(func_code c, const ptr_base &arg)
: ex_base(FUN | (arg->flag() & HAST) | (arg->flag() & HASIDX) | SINGLE),
m_code(c), m_arg(arg)
{
}
