Function strip_outer_parens

nodedb-sql/src/ddl_ast/parse/rls.rs:126–150

Strip at most one matched pair of outer parentheses.

(s: &str)

/// Strip at most one matched pair of outer parentheses.
fn strip_outer_parens(s: &str) -> String {
    let trimmed = s.trim();
    if trimmed.starts_with('(') && trimmed.ends_with(')') {
        let inner = &trimmed[1..trimmed.len() - 1];
        let mut depth = 0i32;
        let mut balanced = true;
        for ch in inner.chars() {
            match ch {
                '(' => depth += 1,
                ')' => {
                    depth -= 1;
                    if depth < 0 {
                        balanced = false;
                        break;
                    }
                }
                _ => {}
            }
        }
        if balanced && depth == 0 {
            return inner.trim().to_string();
        }
    }
    trimmed.to_string()
}

/// Fallback: extract predicate text from the uppercased SQL string when
/// USING appears without space-separated parts matching (e.g. `USING(x=1)`).