Function all_unique

datafusion/sql/src/expr/function.rs:1189–1205

After normalization with [normalize_ident], check whether all params are unique [normalize_ident]: crate::utils::normalize_ident

(params: &[sqlparser::ast::LambdaFunctionParameter])

///
/// [normalize_ident]: crate::utils::normalize_ident
fn all_unique(params: &[sqlparser::ast::LambdaFunctionParameter]) -> bool {
    match params.len() {
        0 | 1 => true,
        2 => {
            crate::utils::normalize_ident(params[0].name.clone())
                != crate::utils::normalize_ident(params[1].name.clone())
        }
        _ => {
            let mut set = HashSet::with_capacity(params.len());

            params
                .iter()
                .map(|p| crate::utils::normalize_ident(p.name.clone()))
                .all(|p| set.insert(p))
        }
    }
}