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use crate::ast::Val;
pub fn eval_f(f: &str, args: &[Val]) -> Val {
match f {
"quote" if args.len() == 1 => args[0].clone(),
_ => Val::Atom("error".to_string()),
}
}
pub fn eval(v: &Val) -> Val {
match v {
v @ Val::Atom(_) => v.clone(),
v @ Val::I64(_) => v.clone(),
v @ Val::String(_) => v.clone(),
v @ Val::List(vs) => {
if vs.is_empty() {
return v.clone();
}
match &vs[0] {
Val::Atom(f) => eval_f(&f, &vs[1..]),
_ => v.clone(),
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn eval_atom() {
assert_eq!(
eval(&Val::Atom("x".to_string())),
Val::Atom("x".to_string())
);
}
#[test]
fn eval_i64() {
assert_eq!(eval(&Val::I64(1)), Val::I64(1));
}
#[test]
fn eval_string() {
assert_eq!(
eval(&Val::String("hello".to_string())),
Val::String("hello".to_string())
);
}
#[test]
fn eval_quote() {
assert_eq!(
eval(&Val::List(vec!(
Val::Atom("quote".to_string()),
Val::Atom("x".to_string())
))),
Val::Atom("x".to_string())
);
}
}
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