ClickHouse/dbms/Parsers/TokenIterator.cpp
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

46 lines
1.4 KiB
C++

#include <Parsers/TokenIterator.h>
namespace DB
{
UnmatchedParentheses checkUnmatchedParentheses(TokenIterator begin, Token * last)
{
/// We have just two kind of parentheses: () and [].
UnmatchedParentheses stack;
for (TokenIterator it = begin; it.isValid() && &it.get() <= last; ++it)
{
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;
}
}