cons-list-test.rs

#[derive(PartialEq)]
pub enum Class {
    Var,
    Function,
    List,
    Str,
    Int,
    Double,
}

struct Cons {
    class: Class,
    symbol: String,
    cdr: Option<Box<Cons>>,
}

impl Cons {
    pub fn new(class: Class, symbol: String, cdr: Option<Cons>) -> Cons {
        Cons {
            class,
            symbol,
            cdr: match cdr {
                Some(x) => Some(Box::new(x)),
                None => None,
            },
        }
    }
}

fn main() {
    let v = Cons::new(Class::Str, "foo".to_string(), None);
    let v = Cons::new(Class::Str, "bar".to_string(), Some(v));
    println!("{}", v.symbol)
}