Parsing coordinate or h3 hex from cli in rust

coord_or_hex.rs

use h3o::LatLng;
use h3o::Resolution;
use hextree::Cell;
use std::str::FromStr;

#[derive(Debug, Clone, Copy)]
pub struct CoordOrHex(Cell);

impl FromStr for CoordOrHex {
    type Err = anyhow::Error;
    fn from_str(s: &str) -> Result<CoordOrHex, anyhow::Error> {
        let raw = if let Some(pos) = s.find(',') {
            let (l, r) = s.split_at(pos);
            let lat_lon = LatLng::new(f64::from_str(l)?, f64::from_str(r)?)?;
            let ci = lat_lon.to_cell(Resolution::Fifteen);
            u64::from(ci)
        } else {
            u64::from_str(s)?
        };
        let cell = Cell::try_from(raw)?;
        Ok(CoordOrHex(cell))
    }
}