Function parse_hop_range

nodedb/src/engine/graph/pattern/compiler/bindings.rs:175–213

Parse hop range: `1..3`, `2`, `..5`, `1..`.

(s: &str)

/// Parse hop range: `1..3`, `2`, `..5`, `1..`.
pub(super) fn parse_hop_range(s: &str) -> crate::Result<(usize, usize)> {
    if s.is_empty() {
        return Ok((1, 1));
    }

    if let Some(dots) = s.find("..") {
        let min_str = s[..dots].trim();
        let max_str = s[dots + 2..].trim();

        let min = if min_str.is_empty() {
            1
        } else {
            min_str.parse().map_err(|_| crate::Error::BadRequest {
                detail: format!("invalid min hops: '{min_str}'"),
            })?
        };

        let max = if max_str.is_empty() {
            10
        } else {
            max_str.parse().map_err(|_| crate::Error::BadRequest {
                detail: format!("invalid max hops: '{max_str}'"),
            })?
        };

        if min > max {
            return Err(crate::Error::BadRequest {
                detail: format!("min hops ({min}) > max hops ({max})"),
            });
        }

        Ok((min, max))
    } else {
        let n: usize = s.parse().map_err(|_| crate::Error::BadRequest {
            detail: format!("invalid hop count: '{s}'"),
        })?;
        Ok((n, n))
    }
}