in src/dialect/bigquery.rs [66:71]
fn is_identifier_start(&self, ch: char) -> bool {
ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch == '_'
// BigQuery supports `@@foo.bar` variable syntax in its procedural language.
// https://cloud.google.com/bigquery/docs/reference/standard-sql/procedural-language#beginexceptionend
|| ch == '@'
}