NSTR_AMBIG        102 regparse.h     #define NSTRING_SET_AMBIG(node)        (node)->u.str.flag |= NSTR_AMBIG
NSTR_AMBIG        106 regparse.h     #define NSTRING_IS_AMBIG(node)        (((node)->u.str.flag & NSTR_AMBIG) != 0)