Files
scylladb/cql3/functions/function.hh
Avi Kivity fcb8d040e8 treewide: use Software Package Data Exchange (SPDX) license identifiers
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.

Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.

The changes we applied mechanically with a script, except to
licenses/README.md.

Closes #9937
2022-01-18 12:15:18 +01:00

79 lines
1.9 KiB
C++

/*
*/
/*
* Copyright (C) 2014-present ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
*/
#pragma once
#include "types.hh"
#include <vector>
#include <optional>
namespace cql3 {
namespace functions {
class function_name;
class function {
public:
using opt_bytes = std::optional<bytes>;
virtual ~function() {}
virtual const function_name& name() const = 0;
virtual const std::vector<data_type>& arg_types() const = 0;
virtual const data_type& return_type() const = 0;
/**
* Checks whether the function is a pure function (as in doesn't depend on, nor produce side effects) or not.
*
* @return <code>true</code> if the function is a pure function, <code>false</code> otherwise.
*/
virtual bool is_pure() const = 0;
/**
* Checks whether the function is a native/hard coded one or not.
*
* @return <code>true</code> if the function is a native/hard coded one, <code>false</code> otherwise.
*/
virtual bool is_native() const = 0;
virtual bool requires_thread() const = 0;
/**
* Checks whether the function is an aggregate function or not.
*
* @return <code>true</code> if the function is an aggregate function, <code>false</code> otherwise.
*/
virtual bool is_aggregate() const = 0;
virtual void print(std::ostream& os) const = 0;
/**
* Returns the name of the function to use within a ResultSet.
*
* @param column_names the names of the columns used to call the function
* @return the name of the function to use within a ResultSet
*/
virtual sstring column_name(const std::vector<sstring>& column_names) const = 0;
friend class function_call;
friend std::ostream& operator<<(std::ostream& os, const function& f);
};
inline
std::ostream&
operator<<(std::ostream& os, const function& f) {
f.print(os);
return os;
}
}
}