use std::collections::HashMap;

struct Context {
    variables: Vec<String>,
    var_lookup: HashMap<String, Var>,
}

#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
struct Var {
    idx: usize,
}

impl Context {
    fn var(&mut self, name: &str) -> Var {
        if let Some(v) = self.var_lookup.get(name) {
            return *v;
        }
        let idx = self.variables.len();
        let var = Var { idx };
        self.variables.push(name.to_string());
        self.var_lookup.insert(name.to_string(), var);
        var
    }
}

impl Var {
    fn show<'r>(&self, ctx: &'r Context) -> &'r str {
        &ctx.variables[self.idx]
    }
}

struct StoryState {
    variables: HashMap<Var, Vec<Var>>,
}

struct Story {
    state: StoryState,
    storylets: Vec<Storylet>,
}

struct Storylet {
}

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
        assert_eq!(2 + 2, 4);
    }
}