ClickHouse/dbms/include/DB/Parsers/ASTFunction.h
2017-01-04 19:31:09 +03:00

82 lines
1.8 KiB
C++

#pragma once
#include <DB/Parsers/ASTWithAlias.h>
#include <DB/Parsers/ASTExpressionList.h>
namespace DB
{
/** AST for function application or operator.
*/
class ASTFunction : public ASTWithAlias
{
public:
/// TODO This is semantic, not syntax. Remove it.
enum FunctionKind
{
UNKNOWN,
TABLE_FUNCTION,
FUNCTION,
AGGREGATE_FUNCTION,
LAMBDA_EXPRESSION,
ARRAY_JOIN,
};
String name;
ASTPtr arguments;
/// parameters - for parametric aggregate function. Example: quantile(0.9)(x) - what in first parens are 'parameters'.
ASTPtr parameters;
FunctionKind kind{UNKNOWN};
public:
ASTFunction() = default;
ASTFunction(const StringRange range_) : ASTWithAlias(range_) {}
String getColumnName() const override;
/** Get text identifying the AST node. */
String getID() const override;
ASTPtr clone() const override;
protected:
void formatImplWithoutAlias(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
};
template <typename... Args>
ASTPtr makeASTFunction(const String & name, Args &&... args)
{
const auto function = std::make_shared<ASTFunction>();
ASTPtr result{function};
function->name = name;
function->arguments = std::make_shared<ASTExpressionList>();
function->children.push_back(function->arguments);
function->arguments->children = { std::forward<Args>(args)... };
return result;
}
template <typename... Args>
ASTPtr makeASTFunction(const String & name, const StringRange & function_range,
const StringRange & arguments_range, Args &&... args)
{
const auto function = std::make_shared<ASTFunction>(function_range);
ASTPtr result{function};
function->name = name;
function->arguments = std::make_shared<ASTExpressionList>(arguments_range);
function->children.push_back(function->arguments);
function->arguments->children = { std::forward<Args>(args)... };
return result;
}
}