Class null_predicate

expr.hh:103–118

};

struct null_predicate : bool_expr {
  virtual ~null_predicate() { }
  const char *negate;
  shared_ptr<value_expr> expr;
  null_predicate(prod *p) : bool_expr(p) {
    negate = ((d6()<4) ? "not " : "");
    expr = value_expr::factory(this);
  }
  virtual void out(std::ostream &out) {
    out << *expr << " is " << negate << "NULL";
  }
  virtual void accept(prod_visitor *v) {
    v->visit(this);
    expr->accept(v);
  }
};

struct exists_predicate : bool_expr {
  shared_ptr<struct query_spec> subquery;