(*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*)
(** Performs a map, but returns the original SMap.t if there is no change **)
let ident_map f map =
let changed = ref false in
let map' =
SMap.map
(fun elem ->
let elem' = f elem in
if elem == elem' then
elem
else (
changed := true;
elem'
))
map
in
if !changed then
map'
else
map