1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
use std::fmt::{self, Display};
#[derive(Debug, PartialEq, Clone)]
pub enum Value {
Num(i32),
Bool(bool),
Sym(String),
App(Box<Value>, Box<Value>),
Lam(String, Box<Value>),
}
impl Display for Value {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Value::Num(i) => write!(f, "{}", i),
Value::Bool(b) => write!(f, "{}", b),
Value::Sym(s) => write!(f, "{}", s),
Value::App(l, r) => write!(f, "({} {})", l, r),
Value::Lam(var, body) => write!(f, "(lam {} {})", var, body),
}
}
}
|
