ClickHouse/src/Parsers/ASTLiteral.h
2020-04-03 18:14:31 +03:00

44 lines
1.1 KiB
C++

#pragma once
#include <Core/Field.h>
#include <Common/FieldVisitors.h>
#include <Parsers/ASTWithAlias.h>
#include <Parsers/TokenIterator.h>
#include <optional>
namespace DB
{
/** Literal (atomic) - number, string, NULL
*/
class ASTLiteral : public ASTWithAlias
{
public:
Field value;
/// For ConstantExpressionTemplate
std::optional<TokenIterator> begin;
std::optional<TokenIterator> end;
ASTLiteral(Field && value_) : value(value_) {}
ASTLiteral(const Field & value_) : value(value_) {}
/** Get the text that identifies this element. */
String getID(char delim) const override { return "Literal" + (delim + applyVisitor(FieldVisitorDump(), value)); }
ASTPtr clone() const override { return std::make_shared<ASTLiteral>(*this); }
void updateTreeHashImpl(SipHash & hash_state) const override;
protected:
void formatImplWithoutAlias(const FormatSettings & settings, FormatState &, FormatStateStacked) const override
{
settings.ostr << applyVisitor(FieldVisitorToString(), value);
}
void appendColumnNameImpl(WriteBuffer & ostr) const override;
};
}