doc & fix: merge_sort problem fix & nil sorting

add complex example

Author: p4r4d0xb0x

doc/nvim-tree-lua.txt

@@ -191,7 +191,6 @@ Subsequent calls to setup will replace the previous configuration.
         number = false,
         relativenumber = false,
         signcolumn = "yes",
-        -- @deprecated
         mappings = {
           custom_only = false,
           list = {
@@ -466,87 +465,37 @@ For example, to use simple user-defined sort_by function is done like this:
     return user_oder
   end
 
-Furthermore, You can try more complex example for `rust` sort_by function is done like this:
+Furthermore, You can try more complex example for sort_by function is done like this:
 
 >
   sort_by = function(tbl)
-    local function tbl_slice(t, first, last)
-      local slice = {}
-      for i = first, last or #t, 1 do
-        table.insert(slice, t[i])
-      end
-      return slice
-    end
-
-    local function merge(t, first, mid, last, comparator)
-      local n1 = mid - first + 1
-      local n2 = last - mid
-      local ls = tbl_slice(t, first, mid)
-      local rs = tbl_slice(t, mid + 1, last)
-      local i = 1
-      local j = 1
-      local k = first
-      while i <= n1 and j <= n2 do
-        if comparator(ls[i], rs[j]) then
-          t[k] = ls[i]
-          i = i + 1
-        else
-          t[k] = rs[j]
-          j = j + 1
-        end
-        k = k + 1
-      end
-      while i <= n1 do
-        t[k] = ls[i]
-        i = i + 1
-        k = k + 1
-      end
-      while j <= n2 do
-        t[k] = rs[j]
-        j = j + 1
-        k = k + 1
-      end
-    end
-
-    local function split_merge(t, first, last, comparator)
-      if (last - first) < 1 then
-        return
-      end
-
-      local mid = math.floor((first + last) / 2)
-
-      split_merge(t, first, mid, comparator)
-      split_merge(t, mid + 1, last, comparator)
-      merge(t, first, mid, last, comparator)
-    end
-
-    local function node_comparator_name_ignorecase_or_not(a, b, ignorecase)
+    table.sort(tbl, function(a, b)
       if not (a and b) then
         return true
       end
-      if a.nodes and not b.nodes then
+      if a.type == "directory" and b.type ~= "directory" then
         return true
-      elseif not a.nodes and b.nodes then
+      elseif a.type ~= "directory" and b.type == "directory" then
         return false
       end
 
-      if ignorecase then
-        return a.name:lower() <= b.name:lower()
-      else
-        return a.name <= b.name
+      if a.type == "link" and b.type ~= "link" then
+        return true
+      elseif a.type ~= "link" and b.type == "link" then
+        return false
       end
-    end
-
 
-    local comparartor = function(a, b) node_comparator_name_ignorecase_or_not(a, b, true) end
-    split_merge(tbl, 1, #tbl, comparartor)
+      return a.name:lower() <= b.name:lower()
+      -- return a.name <= b.name
+    end) -- NOTE: organize directory, link, file in name order
 
+    -- sort by name, is directory?
     local i = 1
     while i <= #tbl do
-      if tbl[i] and tbl[i].nodes then
+      if tbl[i] and tbl[i].type == "directory" then
         local j = i + 1
         while j <= #tbl do
-          if tbl[j] and not tbl[j].nodes and tbl[i].name:lower() == tbl[j].name:lower():match "(.+)%..+$" then
+          if tbl[j] and tbl[j].type ~= "directory" and tbl[i].name:lower() == tbl[j].name:lower():match "(.+)%..+$" then
             local change_target = tbl[j]
             table.remove(tbl, j)
             table.insert(tbl, i, change_target)
@@ -560,12 +509,12 @@ Furthermore, You can try more complex example for `rust` sort_by function is don
 
     local user_order = {}
     for j = 1, #tbl do
-      table.insert(user_order, tbl[j].absolute_path)
+      if tbl[j] then
+        table.insert(user_order, tbl[j].absolute_path)
+      end
     end
     return user_order
-  end,
-
-
+  end
 
 *nvim-tree.hijack_unnamed_buffer_when_opening*
 Opens in place of the unnamed buffer if it's empty.

lua/nvim-tree/explorer/sorters.lua

@@ -68,6 +68,8 @@ end
 function M.merge_sort(t, comparator)
   if type(M.sort_by) == "function" then
     local t_user = {}
+    local origin_index = {}
+
     for _, n in ipairs(t) do
       table.insert(t_user, {
         absolute_path = n.absolute_path,
@@ -77,28 +79,30 @@ function M.merge_sort(t, comparator)
         name = n.name,
         type = n.type,
       })
+      table.insert(origin_index, n)
     end
 
     local user_order = M.sort_by(t_user)
 
     if type(user_order) == "table" then
       -- do merge sort for prevent memory exceed
+
       local user_index = {}
       for k, v in pairs(user_order) do
-        if user_index[v] == nil then
+        if type(v) == "string" and user_index[v] == nil then
           user_index[v] = k
         end
       end
+
+      -- if missing value found, then using origin_index
       local mini_comparator = function(a, b)
-        local a_index = user_index[a.absolute_path]
-        local b_index = user_index[b.absolute_path]
-        if a_index == -1 or a_index == nil then
-          a_index = 9999999999
-        end
-        if b_index == -1 or a_index == nil then
-          b_index = 9999999999
+        local a_index = user_index[a.absolute_path] or origin_index[a.absolute_path]
+        local b_index = user_index[b.absolute_path] or origin_index[b.absolute_path]
+
+        if type(a_index) == "number" and type(b_index) == "number" then
+          return a_index <= b_index
         end
-        return a_index <= b_index
+        return (a_index or 0) <= (b_index or 0)
       end
 
       split_merge(t, 1, #t, mini_comparator) -- sort by user order