switch (SvTYPE(sv)) {
        /* [snip] */
        case SVt_RV: /* [snip IV, PV, etc., all falling through] */
        case SVt_PVBM:  if (SvROK(sv))
                    s = "REF";
                else
                    s = "SCALAR";       break;
        case SVt_PVLV:  s = SvROK(sv) ? "REF"
                /* tied lvalues should appear to be
                 * scalars for backwards compatitbility */
                : (LvTYPE(sv) == 't' || LvTYPE(sv) == 'T')
                    ? "SCALAR" : "LVALUE";  break;
        case SVt_PVAV:  s = "ARRAY";            break;
        case SVt_PVHV:  s = "HASH";         break;
        /* [snip CODE etc.] */