diff --git a/.gitignore b/.gitignore
index 0021882..b8c1b96 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,4 @@
 *.zip
 *.native
 */_build/*
-
+_build/*
diff --git a/lab02/lab2.ml b/lab02/lab2.ml
index c063b5f..7513714 100644
--- a/lab02/lab2.ml
+++ b/lab02/lab2.ml
@@ -99,7 +99,7 @@ let test_filter () =
 let every n l = filteri (fun i _ -> (i + 1) mod n = 0) l;;
 
 (**/**)
-let test_every() =
+let test_every () =
   assert (every 1 [] = []);
   assert (every 2 [1] = []);
   assert (every 3 [1;2;3;4;5;6;7;8;9;10] = [3;6;9]);
diff --git a/lab04/data.txt b/lab04/data.txt
new file mode 100644
index 0000000..b671750
--- /dev/null
+++ b/lab04/data.txt
@@ -0,0 +1,5 @@
+homer simpson 25 # bad at nuclear engineering
+ ned flanders 12abc !! invalid
+    waylon   smithers  100 ! high score
+  gary chalmers 5
+monty burns
diff --git a/lab04/records.ml b/lab04/records.ml
new file mode 100644
index 0000000..6c02ff7
--- /dev/null
+++ b/lab04/records.ml
@@ -0,0 +1,47 @@
+type record = {firstname: string; lastname: string; score: int};;
+
+let new_record f l s = {firstname = f; lastname = l; score = s};;
+
+let rec print_records r =
+  match r with
+  | [] -> ()
+  | x :: xs -> Printf.printf "%3d %s %s\n" x.score x.lastname x.firstname; print_records xs;;
+
+(** [records_insert x l] inserts a record element [x] into
+  * list of records [l]
+  * Requires: [l] is in ascending order. *)
+let rec records_insert x l =
+  match l with
+  | y :: ys when x.score < y.score -> y :: records_insert x ys
+  | _ -> x :: l
+
+(** [records_insertion_sort l] sorts list of records [l] in ascending order *)
+let rec records_insertion_sort l =
+  match l with
+  | [] -> []
+  | x :: xs -> records_insert x (records_insertion_sort xs)
+
+let rec parse l =
+  try
+    Scanf.sscanf l " %s %s %s" (fun f l s ->
+      match int_of_string_opt s with
+      | Some v when v >= 0 && v <= 100 -> Some {firstname = f; lastname = l; score = v}
+      | _ -> None
+    )
+  with
+  | Scanf.Scan_failure _ -> None
+
+let rec read_file acc ic =
+  try
+    match parse @@ input_line ic with
+    | None -> read_file acc ic
+    | Some v -> read_file (v :: acc) ic
+  with
+  | End_of_file -> close_in ic; acc
+
+let () =
+  if Array.length Sys.argv = 1 then
+    Printf.printf "%s: expects 1 file input.\nUsage: \"%s <filename>\"\n" Sys.argv.(0) Sys.argv.(0)
+  else
+    let ic = open_in Sys.argv.(1) in
+    print_records @@ records_insertion_sort @@ read_file [] ic;;