util.set: Change '/' operator from filter to map+filter (nil to drop from set, false...

[prosody.git] / util / set.lua

diff --git a/util/set.lua b/util/set.lua
index 050446ec3f3aca668bd70933e7d5802f6651b4cf..7f45526eb41f97741cfdabd8abc15f114442a0f1 100644 (file)
--- a/util/set.lua
+++ b/util/set.lua
@@ -26,8 +26,9 @@ function set_mt.__div(set, func)
        local new_set, new_items = _M.new();
        local items, new_items = set._items, new_set._items;
        for item in pairs(items) do
-               if func(item) then
-                       new_items[item] = true;
+               local new_item = func(item);
+               if new_item ~= nil then
+                       new_items[new_item] = true;
                end
        end
        return new_set;