Function extract_path

nodedb-query/src/msgpack_scan/field.rs:57–73

Extract a value at a nested path (e.g., `["address", "city"]`). Each segment must be a string key in a nested map.

(buf: &[u8], offset: usize, path: &[&str])

/// Extract a value at a nested path (e.g., `["address", "city"]`).
/// Each segment must be a string key in a nested map.
pub fn extract_path(buf: &[u8], offset: usize, path: &[&str]) -> Option<FieldRange> {
    if path.is_empty() {
        return None;
    }

    let mut current_offset = offset;
    for (i, segment) in path.iter().enumerate() {
        let (value_start, value_end) = extract_field(buf, current_offset, segment)?;
        if i == path.len() - 1 {
            return Some((value_start, value_end));
        }
        // Intermediate segments must be maps — descend into the value
        current_offset = value_start;
    }

    None
}

/// Extract a value using a dot-separated path string (e.g., `"address.city"`).
/// Convenience wrapper over `extract_path`.