Implement lambda application (boom!)

src/primitives.rs

@@ -56,3 +56,24 @@ pub fn sub(mut args: Vec<Datum>) -> Datum {
     }
     Number(r)
 }
+
+pub fn eq(args: Vec<Datum>) -> Datum {
+    if args.len() == 1 {
+        Boolean(true)
+    } else {
+        let first = &args[1];
+
+        for i in 2..args.len() {
+            let current = &args[i];
+            match (first, current) {
+                (Boolean(b1), Boolean(b2)) => {return Boolean(b1 == b2);},
+                (Number(n1), Number(n2)) => {return Boolean(n1 == n2);},
+                _ => {
+                    println!("{:?} is not equal to {:?}", first, current);
+                    return Boolean(false);
+                }
+            }
+        }
+        Boolean(true)
+    }
+}