Add Vylist.in_list for quick checks.

2 files changed, 7 insertions, 0 deletions

diff --git a/src/vylist.ml b/src/vylist.ml
index f18801e..dbcf906 100644
--- a/src/vylist.ml
+++ b/src/vylist.ml
@@ -38,3 +38,9 @@ let complement xs ys =
     in
     if List.length xs < List.length ys then aux xs ys
     else aux ys xs
+
+let in_list xs x =
+    let x' = find ((=) x) xs in
+    match x' with
+    | None -> false
+    | Some _ -> true
diff --git a/src/vylist.mli b/src/vylist.mli
index 9a713b3..2df1c2f 100644
--- a/src/vylist.mli
+++ b/src/vylist.mli
@@ -4,3 +4,4 @@ val replace : ('a -> bool) -> 'a -> 'a list -> 'a list
 val insert_before : ('a -> bool) -> 'a -> 'a list -> 'a list
 val insert_after : ('a -> bool) -> 'a -> 'a list -> 'a	list
 val complement : 'a list -> 'a list -> 'a list option
+val in_list : 'a list -> 'a -> bool