1 files changed, 42 insertions, 0 deletions
diff --git a/motus/lib/criteria.ml b/motus/lib/criteria.ml
new file mode 100644
index 0000000..61bb539
--- /dev/null
+++ b/motus/lib/criteria.ml
@@ -0,0 +1,42 @@
+open StdLabels
+
+type t =
+  | Lenght of int
+  | Contain of char * int option
+  | NotContain of char * int option
+
+(** Return true if the word match the given filter *)
+let check_filter : string -> t -> bool =
+ fun word f ->
+  match f with
+  | Lenght l -> l = String.length word
+  | Contain (c, pos) ->
+    ( match pos with
+    | None -> String.contains word c
+    | Some i -> Char.equal c (String.get word i) )
+  | NotContain (c, pos) ->
+    ( match pos with
+    | None -> not (String.contains word c)
+    | Some i -> not (Char.equal c (String.get word i)) )
+
+
+let is_valid : t -> t -> bool =
+ fun t1 t2 ->
+  match (t1, t2) with
+  | Lenght _, Lenght _ -> false
+  | Contain (c1, _), NotContain (c2, None) -> not (Char.equal c1 c2)
+  | NotContain (c1, None), Contain (c2, _) -> not (Char.equal c1 c2)
+  | Contain (c1, Some i1), Contain (c2, Some i2) -> Char.equal c1 c2 || i1 <> i2
+  | _ -> true
+
+
+(** Add a new filter in the list if it is compatible with the existing ones *)
+let add : t -> t list -> t list =
+ fun t filters ->
+  match List.for_all ~f:(is_valid t) filters with
+  | true -> t :: filters
+  | false -> filters
+
+
+let merge_lists : init:t list -> t list -> t list =
+ fun ~init news -> List.fold_left ~f:(fun acc t -> add t acc) ~init news