parse.y:4405
NODE*
rb_node_newnode(type, a0, a1, a2)
    enum node_type type;
    VALUE a0, a1, a2;
{
    NODE *n = (NODE*)rb_newobj();

    n->flags |= T_NODE;
    nd_set_type(n, type);
    nd_set_line(n, ruby_sourceline);
    n->nd_file = ruby_sourcefile;

    n->u1.value = a0;
    n->u2.value = a1;
    n->u3.value = a2;

    return n;
}
