Method parse_transaction_modes

src/sql-parser/src/parser.rs:8803–8843

(
        &mut self,
        mut required: bool,
    )

    }

    fn parse_transaction_modes(
        &mut self,
        mut required: bool,
    ) -> Result<Vec<TransactionMode>, ParserError> {
        let mut modes = vec![];
        loop {
            let mode = if self.parse_keywords(&[ISOLATION, LEVEL]) {
                let iso_level = if self.parse_keywords(&[READ, UNCOMMITTED]) {
                    TransactionIsolationLevel::ReadUncommitted
                } else if self.parse_keywords(&[READ, COMMITTED]) {
                    TransactionIsolationLevel::ReadCommitted
                } else if self.parse_keywords(&[REPEATABLE, READ]) {
                    TransactionIsolationLevel::RepeatableRead
                } else if self.parse_keyword(SERIALIZABLE) {
                    TransactionIsolationLevel::Serializable
                } else if self.parse_keywords(&[STRONG, SESSION, SERIALIZABLE]) {
                    TransactionIsolationLevel::StrongSessionSerializable
                } else if self.parse_keywords(&[STRICT, SERIALIZABLE]) {
                    TransactionIsolationLevel::StrictSerializable
                } else {
                    self.expected(self.peek_pos(), "isolation level", self.peek_token())?
                };
                TransactionMode::IsolationLevel(iso_level)
            } else if self.parse_keywords(&[READ, ONLY]) {
                TransactionMode::AccessMode(TransactionAccessMode::ReadOnly)
            } else if self.parse_keywords(&[READ, WRITE]) {
                TransactionMode::AccessMode(TransactionAccessMode::ReadWrite)
            } else if required {
                self.expected(self.peek_pos(), "transaction mode", self.peek_token())?
            } else {
                break;
            };
            modes.push(mode);
            // ANSI requires a comma after each transaction mode, but
            // PostgreSQL, for historical reasons, does not. We follow
            // PostgreSQL in making the comma optional, since that is strictly
            // more general.
            required = self.consume_token(&Token::Comma);
        }
        Ok(modes)
    }

    fn parse_commit(&mut self) -> Result<Statement<Raw>, ParserError> {
        Ok(Statement::Commit(CommitStatement {