that stuff was really not necessary

day2.ml

@@ -1,60 +1,32 @@
-module type Part = sig
-  type t
-  val parse_line: string -> t
-  val ok: t -> bool
-end
+type line = {first: int; second: int; char: char; pass: string}
 
-let parse_line' f str = Scanf.sscanf str "%d - %d %c : %s" f
+let parse_line str = Scanf.sscanf str "%d - %d %c : %s"
+  (fun first second char pass -> {first; second; char; pass})
 
 
-module Part1: Part = struct
-  type t = {min: int; max: int; char: char; pass: string}
+let count_str c str =
+  let res = ref 0 in
+  String.iter (fun d -> if c = d then incr res) str;
+  !res
 
-  let parse_line = parse_line'
-    (fun min max char pass -> {min; max; char; pass})
+let ok1 {first; second; char; pass} =
+  let res = count_str char pass in
+  res >= first && res <= second
 
-  let count c str =
-    let res = ref 0 in
-    String.iter (fun d -> if c = d then incr res) str;
-    !res
-
-  let ok {min; max; char; pass} =
-    let res = count char pass in
-    res >= min && res <= max
-end
+let ok2 {first; second; char; pass} =
+  (pass.[first - 1] = char) <> (pass.[second - 1] = char)
 
 
-module Part2: Part = struct
-  type t = {pos1: int; pos2: int; char: char; pass: string}
-
-  let parse_line = parse_line'
-    (fun pos1 pos2 char pass -> {pos1 = pos1 - 1; pos2 = pos2 - 1; char; pass})
-
-  let ok {pos1; pos2; char; pass} =
-    (pass.[pos1] = char) <> (pass.[pos2] = char)
-end
-
-
-module type Main = sig val run: string -> unit end
-
-module Main(P: Part)(): Main = struct
-  open P
-
-  let count_all = ref 0
-  let count_ok = ref 0
+let main' ok input =
+  let count_all = ref 0 in
+  let count_ok = ref 0 in
   let check l =
     incr count_all;
-    if ok l then incr count_ok
+    if ok l then incr count_ok in
+  Bracket.infile_iter_lines input ~line:parse_line ~iter:check;
+  Printf.printf "%d out of %d ok\n" !count_ok !count_all
 
-  let run input =
-    Bracket.infile_iter_lines input ~line:parse_line ~iter:check;
-    Printf.printf "%d out of %d ok\n" !count_ok !count_all
-end
-
-let main' (module P: Part) =
-  let module M = Main(P)() in M.run
-
-let mains = [|main' (module Part1); main' (module Part2)|]
+let mains = [|main' ok1; main' ok2|]
 
 let main = function
   | [part; input] -> mains.(int_of_string part - 1) input