2017-07-13 05:48:51 +00:00
|
|
|
#include <Parsers/TokenIterator.h>
|
|
|
|
|
|
|
|
|
|
|
|
namespace DB
|
|
|
|
{
|
|
|
|
|
2022-10-14 14:20:56 +00:00
|
|
|
const Token & Tokens::operator[](size_t index)
|
|
|
|
{
|
|
|
|
if (likely(index < data.size()))
|
|
|
|
return data[index];
|
|
|
|
|
|
|
|
while (data.empty() || !data.back().isEnd())
|
|
|
|
{
|
|
|
|
Token token = lexer.nextToken();
|
|
|
|
|
|
|
|
if (token.isSignificant())
|
|
|
|
{
|
|
|
|
data.emplace_back(std::move(token));
|
|
|
|
if (index < data.size())
|
|
|
|
return data[index];
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return data.back();
|
|
|
|
}
|
|
|
|
|
2021-01-31 23:10:41 +00:00
|
|
|
UnmatchedParentheses checkUnmatchedParentheses(TokenIterator begin)
|
2017-07-13 05:48:51 +00:00
|
|
|
{
|
|
|
|
/// We have just two kind of parentheses: () and [].
|
|
|
|
UnmatchedParentheses stack;
|
|
|
|
|
2021-01-31 23:10:41 +00:00
|
|
|
/// We have to iterate through all tokens until the end to avoid false positive "Unmatched parentheses" error
|
|
|
|
/// when parser failed in the middle of the query.
|
|
|
|
for (TokenIterator it = begin; it.isValid(); ++it)
|
2017-07-13 05:48:51 +00:00
|
|
|
{
|
|
|
|
if (it->type == TokenType::OpeningRoundBracket || it->type == TokenType::OpeningSquareBracket)
|
|
|
|
{
|
|
|
|
stack.push_back(*it);
|
|
|
|
}
|
|
|
|
else if (it->type == TokenType::ClosingRoundBracket || it->type == TokenType::ClosingSquareBracket)
|
|
|
|
{
|
|
|
|
if (stack.empty())
|
|
|
|
{
|
|
|
|
/// Excessive closing bracket.
|
|
|
|
stack.push_back(*it);
|
|
|
|
return stack;
|
|
|
|
}
|
|
|
|
else if ((stack.back().type == TokenType::OpeningRoundBracket && it->type == TokenType::ClosingRoundBracket)
|
|
|
|
|| (stack.back().type == TokenType::OpeningSquareBracket && it->type == TokenType::ClosingSquareBracket))
|
|
|
|
{
|
|
|
|
/// Valid match.
|
|
|
|
stack.pop_back();
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
/// Closing bracket type doesn't match opening bracket type.
|
|
|
|
stack.push_back(*it);
|
|
|
|
return stack;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/// If stack is not empty, we have unclosed brackets.
|
|
|
|
return stack;
|
|
|
|
}
|
|
|
|
|
|
|
|
}
|