fix evaluation behavior mismatch between functions and lambdas

Signed-off-by: Ava Hahn <ava@sunnypup.io>

tests/test_eval.rs

@@ -1,6 +1,7 @@
 mod eval_tests {
     use relish::ast::{eval, lex, SymTable};
     use relish::ast::{Args, Ctr, Seg, Symbol, UserFn, ValueType};
+    use relish::stdlib::{dynamic_stdlib, static_stdlib};
 
     #[test]
     fn eval_simple() {
@@ -92,4 +93,21 @@ mod eval_tests {
             }
         }
     }
+
+    #[test]
+    fn func_lambda_equivalency() {
+        let comparator = "(def apply 'applicator' (fn x) (fn x))";
+        let lh_doc = "(apply car (1 2 3))";
+        let rh_doc = "(apply (lambda (x) (car x)) (1 2 3))";
+
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms);
+        dynamic_stdlib(&mut syms, None);
+
+        eval(&lex(&comparator.to_string()).unwrap(), &mut syms).unwrap();
+        assert_eq!(
+            eval(&lex(&lh_doc.to_string()).unwrap(), &mut syms).unwrap(),
+            eval(&lex(&rh_doc.to_string()).unwrap(), &mut syms).unwrap(),
+        );
+    }
 }