Make symlink signatures more consistent

lib_eio/fs.ml

@@ -70,7 +70,7 @@ module Pi = struct
     val rmdir : t -> path -> unit
     val rename : t -> path -> _ dir -> path -> unit
     val read_link : t -> path -> string
-    val symlink : t -> path -> link_to:path -> unit
+    val symlink : link_to:path -> t -> path -> unit
     val pp : t Fmt.t
     val native : t -> string -> string option
   end

lib_eio_linux/eio_linux.ml

@@ -600,8 +600,8 @@ end = struct
     | Some fd2 -> Low_level.rename t.fd old_path fd2 new_path
     | None -> raise (Unix.Unix_error (Unix.EXDEV, "rename-dst", new_path))
 
-  let symlink t path ~link_to =
-    Low_level.symlink link_to t.fd path
+  let symlink ~link_to t path =
+    Low_level.symlink ~link_to t.fd path
 
   let pp f t = Fmt.string f (String.escaped t.label)
 

lib_eio_linux/low_level.ml

@@ -452,7 +452,7 @@ let rename old_dir old_path new_dir new_path =
       new_parent new_leaf
   with Unix.Unix_error (code, name, arg) -> raise @@ Err.wrap_fs code name arg
 
-let symlink link_to dir path =
+let symlink ~link_to dir path =
   with_parent_dir "symlinkat-new" dir path @@ fun parent leaf ->
   try
     eio_symlinkat link_to parent leaf

lib_eio_linux/low_level.mli

@@ -150,8 +150,8 @@ val unlink : rmdir:bool -> dir_fd -> string -> unit
 val rename : dir_fd -> string -> dir_fd -> string -> unit
 (** [rename old_dir old_path new_dir new_path] renames [old_dir / old_path] as [new_dir / new_path]. *)
 
-val symlink : string -> dir_fd -> string -> unit
-(** [symlink link_to dir path] creates a new symlink at [dir / path] pointing to [link_to]. *)
+val symlink : link_to:string -> dir_fd -> string -> unit
+(** [symlink ~link_to dir path] creates a new symlink at [dir / path] pointing to [link_to]. *)
 
 val pipe : sw:Switch.t -> fd * fd
 (** [pipe ~sw] returns a pair [r, w] with the readable and writeable ends of a new pipe. *)

lib_eio_posix/fs.ml

@@ -94,8 +94,8 @@ end = struct
     | None -> invalid_arg "Target is not an eio_posix directory!"
     | Some new_dir -> Err.run (Low_level.rename t.fd old_path new_dir) new_path
 
-  let symlink t path ~link_to =
-    Err.run (Low_level.symlink link_to t.fd) path
+  let symlink ~link_to t path =
+    Err.run (Low_level.symlink ~link_to t.fd) path
 
   let open_dir t ~sw path =
     let flags = Low_level.Open_flags.(rdonly + directory +? path) in

lib_eio_posix/low_level.ml

@@ -416,7 +416,7 @@ let rename old_dir old_path new_dir new_path =
 
 external eio_symlinkat : string -> Unix.file_descr -> string -> unit = "caml_eio_posix_symlinkat"
 
-let symlink link_to new_dir new_path =
+let symlink ~link_to new_dir new_path =
   in_worker_thread "symlink" @@ fun () ->
   Resolve.with_parent "symlink-new" new_dir new_path @@ fun new_dir new_path ->
   let new_dir = Option.value new_dir ~default:at_fdcwd in

lib_eio_posix/low_level.mli

@@ -78,8 +78,8 @@ val mkdir : mode:int -> dir_fd -> string -> unit
 val unlink : dir:bool -> dir_fd -> string -> unit
 val rename : dir_fd -> string -> dir_fd -> string -> unit
 
-val symlink : string -> dir_fd -> string -> unit
-(** [symlink link_to dir path] will create a new symlink at [dir / path]
+val symlink : link_to:string -> dir_fd -> string -> unit
+(** [symlink ~link_to dir path] will create a new symlink at [dir / path]
     linking to [link_to]. *)
 
 val readdir : dir_fd -> string -> string array

lib_eio_windows/fs.ml

@@ -172,9 +172,9 @@ end = struct
       with_parent_dir new_dir new_path @@ fun new_dir new_path ->
       Err.run (Low_level.rename ?old_dir old_path ?new_dir) new_path
 
-  let symlink t path ~link_to =
+  let symlink ~link_to t path =
     with_parent_dir t path @@ fun dirfd path ->
-    Err.run (Low_level.symlink link_to dirfd) path
+    Err.run (Low_level.symlink ~link_to dirfd) path
 
   let close t = t.closed <- true
 

lib_eio_windows/low_level.ml

@@ -237,10 +237,10 @@ let rename ?old_dir old_path ?new_dir new_path =
 
 external eio_symlinkat : string -> Unix.file_descr option -> string -> unit = "caml_eio_windows_symlinkat"
 
-let symlink old_path new_dir new_path =
+let symlink ~link_to new_dir new_path =
   with_dirfd "symlink-new" new_dir @@ fun new_dir ->
   in_worker_thread @@ fun () ->
-  eio_symlinkat old_path new_dir new_path
+  eio_symlinkat link_to new_dir new_path
 
 let lseek fd off cmd =
   Fd.use_exn "lseek" fd @@ fun fd ->

lib_eio_windows/low_level.mli

@@ -48,8 +48,9 @@ val mkdir : ?dirfd:fd -> ?nofollow:bool -> mode:int -> string -> unit
 val unlink : ?dirfd:fd -> dir:bool -> string -> unit
 val rename : ?old_dir:fd -> string -> ?new_dir:fd -> string -> unit
 
-val symlink : string -> fd option -> string -> unit
-(** [symlink link_to dir path] creates a new symbolic link [dir / path] pointing to [link_to] *)
+val symlink : link_to:string -> fd option -> string -> unit
+(** [symlink ~link_to dir path] will create a new symlink at [dir / path]
+    linking to [link_to]. *)
 
 val readdir : string -> string array