dpath.rs

use std::collections::HashMap;

trait Descend {
    fn descend(&self, key: &str, rem_path: Option<&str>) -> String;
}

impl Descend for HashMap<String, String> {
    fn descend(&self, key: &str, rem_path: Option<&str>) -> String {
        let obj = &self[key];

        if rem_path.is_some() {
            panic!("oh no")
        } else {
            obj.clone()
        }
    }
}

impl<T: Descend> Descend for HashMap<String, T> {
    fn descend(&self, key: &str, rem_path: Option<&str>) -> String {
        let obj = &self[key];

        if let Some(rp) = rem_path {
            dpath(obj, rp)
        } else {
            panic!("oh no")
        }
    }
}

impl Descend for Vec<String> {
    fn descend(&self, key: &str, rem_path: Option<&str>) -> String {
        let obj = &self[key.parse::<usize>().unwrap()];

        if rem_path.is_some() {
            panic!("oh no")
        } else {
            obj.clone()
        }
    }
}

impl<T: Descend> Descend for Vec<T> {
    fn descend(&self, key: &str, rem_path: Option<&str>) -> String {
        let obj = &self[key.parse::<usize>().unwrap()];

        if let Some(rp) = rem_path {
            dpath(obj, rp)
        } else {
            panic!("oh no")
        }
    }
}

fn dpath<T: Descend>(map: &T, path: &str) -> String {
    let mut pi = path.splitn(2, "/");
    map.descend(pi.next().unwrap(), pi.next())
}