ClickHouse/dbms/src/Parsers/IParserBase.cpp

#include <DB/Parsers/IParserBase.h>


namespace DB
{

namespace ErrorCodes
{
    extern const int LOGICAL_ERROR;
}


bool IParserBase::parse(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
    Pos begin = pos;
    Pos new_max_parsed_pos = pos;
    Expected new_expected = getName();

    bool res = parseImpl(pos, end, node, new_max_parsed_pos, new_expected);

    if (pos > new_max_parsed_pos)
        new_max_parsed_pos = pos;

    if (new_max_parsed_pos > max_parsed_pos)
        max_parsed_pos = new_max_parsed_pos;

    if (!res && new_max_parsed_pos >= max_parsed_pos)
        expected = new_expected;

    if (pos > end)
        throw Exception("Logical error: pos > end.", ErrorCodes::LOGICAL_ERROR);

    if (!res)
    {
        node = nullptr;
        pos = begin;
    }

    return res;
}

}