Add reverse function to stdlib

examples/playground.sb

@@ -1,5 +1,5 @@
 fn main() {
-    let x = 10
-    x = 5
-    println("Hello World!")
+    let arr = [1, 2, 3, 4, 5]
+
+    println(rev(arr))
 }

lib/stdio.sb

@@ -17,4 +17,22 @@ fn len(arr) {
     }
 
     return c
+}
+
+// Reverses an array
+// TODO: fix me!
+fn rev(arr) {
+
+    let l = len(arr)
+    let new_arr = []
+
+    let i = 0
+    let j = l
+    while i < l {
+        new_arr[i] = arr[j]
+        i = i - 1
+        j = j - 1
+    }
+
+    return new_arr
 }

src/parser/tests.rs

@@ -554,3 +554,17 @@ fn test_function_multiple_args() {
     let tree = parse(tokens, Some(raw.to_string()));
     assert!(tree.is_ok())
 }
+
+#[test]
+#[ignore]
+fn test_array_position_assignment() {
+    let raw = "
+    fn main() {
+        new_arr[i] = arr[j]
+    }
+    }
+    ";
+    let tokens = tokenize(raw);
+    let tree = parse(tokens, Some(raw.to_string()));
+    assert!(tree.is_ok())
+}