// Copyright 2023 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once

#include <Core/Field.h>
#include <Parsers/IAST.h>
#include <Parsers/IParser.h>

#include <memory>


namespace DB
{
class Context;
class IDataType;


/** Evaluate constant expression and its type.
  * Used in rare cases - for elements of set for IN, for data to INSERT.
  * Quite suboptimal.
  */
std::pair<Field, std::shared_ptr<const IDataType>> evaluateConstantExpression(
    const ASTPtr & node,
    const Context & context);


/** Evaluate constant expression
  *  and returns ASTLiteral with its value.
  */
ASTPtr evaluateConstantExpressionAsLiteral(const ASTPtr & node, const Context & context);


/** Evaluate constant expression
  *  and returns ASTLiteral with its value.
  * Also, if AST is identifier, then return string literal with its name.
  * Useful in places where some name may be specified as identifier, or as result of a constant expression.
  */
ASTPtr evaluateConstantExpressionOrIdentifierAsLiteral(const ASTPtr & node, const Context & context);

} // namespace DB