feat: eval/apply functions

src/env/core.rs

@@ -8,6 +8,33 @@ use crate::node::Node;
 
 pub(super) fn core() -> HashMap<String, Node> {
     [
+        // Meta
+        (
+            "eval",
+            Node::NativeFunc(|env, args| {
+                arg_count!(1, args.len());
+                let ast = args.into_iter().next().unwrap();
+                eval_node(env, ast)
+            }),
+        ),
+        (
+            "apply",
+            Node::NativeFunc(|env, args| {
+                arg_count!(2, args.len());
+
+                let mut args = args.into_iter();
+                let operator = args.next().unwrap();
+                let args = match args.next().unwrap() {
+                    Node::List(list) => list,
+                    _ => Err(Error::ExpectedList)?,
+                };
+
+                let mut list = vec![operator];
+                list.extend(args);
+
+                eval_node(env, Node::List(list))
+            }),
+        ),
         // Arithmetic operations
         (
             "+",

src/evaluator.rs

@@ -92,6 +92,9 @@ mod test {
     #[case(":owo", ":owo")]
     #[case("()", "()")]
     #[case("nil", "()")]
+    // Meta
+    #[case("(eval (list + 1 1))", "2")]
+    #[case("(apply + (list 1 2 3))", "6")]
     // Arithmetic
     #[case("(+ 1 2)", "3")]
     #[case("(- 5 1)", "4")]