refactor(ops): rework binary and extra

lib/excache/store/ops/binary.ex

@@ -55,6 +55,9 @@ defmodule Excache.Store.Ops.Binary do
       :wrongtype ->
         {:error, :wrongtype}
 
+      {:ok, current, _ea, _exists} when value == "" ->
+        {:ok, byte_size(current)}
+
       {:ok, current, ea, _exists} ->
         updated = overwrite(current, offset, value)
         store(table, key, updated, ea)
@@ -149,8 +152,6 @@ defmodule Excache.Store.Ops.Binary do
     end
   end
 
-  defp overwrite(current, offset, value) when value == "", do: current
-
   defp overwrite(current, offset, value) do
     size = byte_size(current)
     padded = if size < offset, do: current <> :binary.copy(<<0>>, offset - size), else: current

lib/excache/store/ops/extra.ex

@@ -313,22 +313,15 @@ defmodule Excache.Store.Ops.Extra do
     scanned =
       if rank < 0, do: Enum.reverse(indexed), else: indexed
 
-    skip = abs(rank) - 1
+    matches = collectMatches(scanned, element, abs(rank) - 1, matchLimit(count), maxlen, 0, [])
-    limit = if count == 0, do: :all, else: count
 
-    collectMatches(scanned, element, skip, limit, maxlen, 0, [])
+    if count == nil, do: List.first(matches), else: matches
-    |> then(fn matches ->
-      if count == nil do
-        case matches do
-          [] -> nil
-          [first | _] -> first
-        end
-      else
-        matches
-      end
-    end)
   end
 
+  defp matchLimit(nil), do: 1
+  defp matchLimit(0), do: :all
+  defp matchLimit(count), do: count
+
   defp collectMatches([], _element, _skip, _limit, _maxlen, _compared, acc),
     do: Enum.reverse(acc)