Merge pull request #833 from m-click/unlink-missing-ok

Add missing_ok to Eio.Path.unlink (#828)

Author: talex5

lib_eio/path.ml

@@ -160,11 +160,13 @@ let save ?append ~create path data =
   with_open_out ?append ~create path @@ fun flow ->
   Flow.copy_string data flow
 
-let unlink t =
+let unlink ?(missing_ok=false) t =
   let (Resource.T (dir, ops), path) = t in
   let module X = (val (Resource.get ops Fs.Pi.Dir)) in
   try X.unlink dir path
-  with Exn.Io _ as ex ->
+  with
+  | Exn.Io (Fs.(E (Not_found _)), _) when missing_ok -> ()
+  | Exn.Io _ as ex ->
     let bt = Printexc.get_raw_backtrace () in
     Exn.reraise_with_context ex bt "removing file %a" pp t
 

lib_eio/path.mli

@@ -183,9 +183,12 @@ val read_link : _ t -> string
 
 (** {1 Other} *)
 
-val unlink : _ t -> unit
+val unlink : ?missing_ok:bool -> _ t -> unit
 (** [unlink t] removes directory entry [t].
 
+    @param missing_ok If [false] (the default), raise an {!Fs.Not_found} IO error if [t] doesn't exist.
+                      If [true], do nothing if [t] is missing.
+
     Note: this cannot be used to unlink directories.
     Use {!rmdir} for directories. *)