return ti == (TINFO_color + rl);
}
-ex color_trace(const ex & e, unsigned char rl)
+/** Check whether a given tinfo key (as returned by return_type_tinfo()
+ * is that of a color object (with an arbitrary representation label). */
+static bool is_color_tinfo(unsigned ti)
+{
+ return (ti & ~0xff) == TINFO_color;
+}
+
+/** Extract representation label from tinfo key (as returned by
+ * return_type_tinfo()). */
+static unsigned char get_representation_label(unsigned ti)
+{
+ return ti & 0xff;
+}
+
+ex color_trace(const ex & e, const std::set<unsigned char> & rls)
{
if (is_a<color>(e)) {
- if (ex_to<color>(e).get_representation_label() == rl
- && is_a<su3one>(e.op(0)))
+ unsigned char rl = ex_to<color>(e).get_representation_label();
+
+ // Are we taking the trace over this object's representation label?
+ if (rls.find(rl) == rls.end())
+ return e;
+
+ // Yes, all generators are traceless, except for color_ONE
+ if (is_a<su3one>(e.op(0)))
return _ex3;
else
return _ex0;
ex prod = _ex1;
for (size_t i=0; i<e.nops(); i++) {
const ex &o = e.op(i);
- if (is_color_tinfo(o.return_type_tinfo(), rl))
- prod *= color_trace(o, rl);
+ if (is_color_tinfo(o.return_type_tinfo()))
+ prod *= color_trace(o, rls);
else
prod *= o;
}
} else if (is_exactly_a<ncmul>(e)) {
- if (!is_color_tinfo(e.return_type_tinfo(), rl))
- return _ex0;
+ unsigned char rl = get_representation_label(e.return_type_tinfo());
- // Expand product, if necessary
+ // Are we taking the trace over this string's representation label?
+ if (rls.find(rl) == rls.end())
+ return e;
+
+ // Yes, expand product if necessary
ex e_expanded = e.expand();
if (!is_a<ncmul>(e_expanded))
- return color_trace(e_expanded, rl);
+ return color_trace(e_expanded, rls);
size_t num = e.nops();
} else if (e.nops() > 0) {
// Trace maps to all other container classes (this includes sums)
- pointer_to_map_function_1arg<unsigned char> fcn(color_trace, rl);
+ pointer_to_map_function_1arg<const std::set<unsigned char> &> fcn(color_trace, rls);
return e.map(fcn);
} else
return _ex0;
}
+ex color_trace(const ex & e, const lst & rll)
+{
+ // Convert list to set
+ std::set<unsigned char> rls;
+ for (lst::const_iterator i = rll.begin(); i != rll.end(); ++i) {
+ if (i->info(info_flags::nonnegint))
+ rls.insert(ex_to<numeric>(*i).to_int());
+ }
+
+ return color_trace(e, rls);
+}
+
+ex color_trace(const ex & e, unsigned char rl)
+{
+ // Convert label to set
+ std::set<unsigned char> rls;
+ rls.insert(rl);
+
+ return color_trace(e, rls);
+}
+
} // namespace GiNaC