Sorting files numerically

[zefr0x]

Is your feature request related to a problem? Please describe.
I'm always frustrated when I have a directory that has number-named files.
For example NvimTree will display them like that:

10
11
12
13
14
15
16
17
18
19
'1 hello'
'1 hello 4'
2
20
'3 hello'
'3 hello 5'
6
7
8
9
'hello 3'

But the normal order I want them to be in is like:

'1 hello'
'1 hello 4'
2
'3 hello'
'3 hello 5'
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
'hello 3'

It's the same default behavior of the ls GUN utility in Linux, but the ls has an option -v to treat filename numerically. https://unix.stackexchange.com/questions/33909/list-files-sorted-numerically

Most times I need numbered files sorted with the numerically normal order so I can walk between them easily.

Describe the solution you'd like
Maybe adding a new type to the sort_by option to do that type of sorting.

Describe alternatives you've considered
Maybe I just can create a function to do that since sort_by option support passing a function.

[alex-courtis]

You can add this functionality yourself. See :help nvim-tree.sort_by

This might get you started:

  local sort_by = function(nodes)
    table.sort(nodes, function(a, b)
      local a_num = string.match(a.name, "^[0-9]+")
      local b_num = string.match(b.name, "^[0-9]+")
      if a_num and b_num then
        return a_num < b_num
      else
        -- we need to do something here
        return false
      end
    end)
  end

[zefr0x]

I'm not even a beginner in Lua, but I made this:

local compare = function(left, right)
	left = left.name:lower()
	right = right.name:lower()

	for i = 1, string.len(left), 1 do
		local l = string.sub(left, i, -1)
		local r = string.sub(right, i, -1)

		if l == r then
			return false
		elseif type(tonumber(string.sub(l, 1, 1))) == "number" and type(tonumber(string.sub(r, 1, 1))) == "number" then
			return tonumber(string.match(l, "^[0-9]+")) < tonumber(string.match(r, "^[0-9]+"))
		elseif l[1] == r[1] then
			goto continue
		else
			return l < r
		end
		::continue::
	end
end


-- nvim-tree.lua
require("nvim-tree").setup({
	sort_by = function(nodes)
		table.sort(nodes, compare)
	end,
})

It seems to work fine. If any one have any optimizations or fail points please tell me.

References:

https://github.com/lifthrasiir/rust-natord/blob/93e5f0ace208e73ddfaaa77ec1605584c8f22a14/lib.rs#L142

https://github.com/lifthrasiir/rust-natord/blob/93e5f0ace208e73ddfaaa77ec1605584c8f22a14/lib.rs#L37

[zefr0x]

It would be great if you added this Recipe to the wiki.

Done.

[admbeck]

This sort produces inconsistent results for me. After each write of the file nvim-tree re-sorts itself and fails to sort files and directories properly. I am not sure why it happens

[zefr0x]

I think that this work:

local compare = function(left, right)
	left = left.name:lower()
	right = right.name:lower()

	for i = 1, string.len(left), 1 do
		local l = string.sub(left, i, -1)
		local r = string.sub(right, i, -1)

		if l == r then
			return false
		elseif type(tonumber(string.sub(l, 1, 1))) == "number" and type(tonumber(string.sub(r, 1, 1))) == "number" then
			return tonumber(string.match(l, "^[0-9]+")) < tonumber(string.match(r, "^[0-9]+"))
-		elseif l[1] == r[1] then
-			goto continue
		else
			return l < r
		end
-		::continue::
	end
end

My subconscious mind told me to get the else case out of the for loop, and it worked after this change.

It appears that this else case was not reachable, since the l and r are not indexable and the result will be nil, so this statement will be always true. Anyway it was a duplicate statement since the l == r is checked in the first statement.

Now, numbers sorting will work only if the number is in the start of the name. For now I'm trying to make it work for number if they are in the middle of end of the name.

Sorry about that, but my lua knowledge is not great, so my code is messy.

If you found any problems just say 👍

[zefr0x]

This is it, the fixed and improved version:

local function natural_cmp(left, right)
	left = left.name:lower()
	right = right.name:lower()

	if left == right then
		return false
	end

	for i = 1, math.max(string.len(left), string.len(right)), 1 do
		local l = string.sub(left, i, -1)
		local r = string.sub(right, i, -1)

		if type(tonumber(string.sub(l, 1, 1))) == "number" and type(tonumber(string.sub(r, 1, 1))) == "number" then
			local l_number = tonumber(string.match(l, "^[0-9]+"))
			local r_number = tonumber(string.match(r, "^[0-9]+"))

			if l_number ~= r_number then
				return l_number < r_number
			end
		elseif string.sub(l, 1, 1) ~= string.sub(r, 1, 1) then
			return l < r
		end
	end
end

require("nvim-tree").setup({
	sort_by = function(nodes)
		table.sort(nodes, natural_cmp)
	end,
})

[alex-courtis]

Thanks for the update!

[russarr]

Hi. I have a problem.
Sorting mixes files and directories. Is there a way to make directories at the top of the list as usual.

[alex-courtis]

Hi. I have a problem. Sorting mixes files and directories. Is there a way to make directories at the top of the list as usual.

In your :help nvim-tree.sort_by function you can compare first on:

type:          "directory" | "file" | "link"

[russarr]

I don't understand how to use this parameter with a function from this topic
require("nvim-tree").setup({ sort_by = function(nodes) table.sort(nodes, natural_cmp) end, })
How should I specify the directory parameter.

[alex-courtis]

How should I specify the directory parameter.

Extending the example in :help nvim-tree.sort_by to sort by length of name with directories first:

local sort_by = function(nodes)
  table.sort(nodes, function(a, b)
    -- directories first
    if a.type ~= "directory" and b.type == "directory" then
      return false
    elseif a.type == "directory" and b.type ~= "directory" then
      return true
    end

    -- sort by name length
    return #a.name < #b.name
  end)
end

[alex-courtis]

Refactored as per the above example with the comparison function:

local natural_cmp = function(left, right)
  -- directories first
  if left.type ~= "directory" and right.type == "directory" then
---

[russarr]

I need help again. I'm trying to merge two recipes:

• https://github.com/nvim-tree/nvim-tree.lua/wiki/Recipes#sorting-files-naturally-respecting-numbers-within-files-names
• https://github.com/nvim-tree/nvim-tree.lua/wiki/Recipes#cycle-sort-methods
  Individually, they work perfectly
  For example, this works:

    require("nvim-tree").setup({
        sort_by = sort_by_natural,
    })

But if I try to add a sorting function to the list for cycling from second reciept, it doesn't work. Cycling is working, but natural sort doesn't. It just sorting by "name".

    local SORT_METHODS = {
      sort_by_natural,
      "case_sensitive",
      "modification_time",
      "extension",
    }
...
    require("nvim-tree").setup({
        sort_by = sort_by,
    })

[alex-courtis]

A :help nvim-tree.sort.sorter may return either a string with the predefined sorter or do the actual sort.

This synthetic example might help:

local sort_by_len = true

local sorter = function(nodes)
  if sort_by_len then
    table.sort(nodes, function(a, b)
      return #a.name < #b.name
    end)
  else
    return "modification_time"
  end
end

local cycle_sort = function()
  sort_by_len = not sort_by_len
  api.tree.reload()
end

---

  vim.keymap.set('n', 'T', cycle_sort, opts('Cycle Sort'))

[russarr]

Thanks!
So this in my resulting sort functions. Difference from original reciepts:

• when sorting by name with the natural order of numbers, the directories remain on top
• cycling between "natural names" and "modification_time"

    local sort_by_name = true
    local function sort_by_natural(nodes)
      local function sorter(left, right)
        if left.type ~= "directory" and right.type == "directory" then
          return false
        elseif left.type == "directory" and right.type ~= "directory" then
          return true
        end
        left = left.name:lower()
        right = right.name:lower()

        if left == right then
          return false
        end

        for i = 1, math.max(string.len(left), string.len(right)), 1 do
          local l = string.sub(left, i, -1)
          local r = string.sub(right, i, -1)

          if
              type(tonumber(string.sub(l, 1, 1))) == "number"
              and type(tonumber(string.sub(r, 1, 1))) == "number"
          then
            local l_number = tonumber(string.match(l, "^[0-9]+"))
            local r_number = tonumber(string.match(r, "^[0-9]+"))

            if l_number ~= r_number then
              return l_number < r_number
            end
          elseif string.sub(l, 1, 1) ~= string.sub(r, 1, 1) then
            return l < r
          end
        end
      end

      if sort_by_name then
        table.sort(nodes, sorter)
      else
        return "modification_time"
      end
    end

    local cycle_sort = function()
      sort_by_name = not sort_by_name
      api.tree.reload()
      if sort_by_name then
        vim.notify("Sorting by name")
      else
        vim.notify("Sorting by modification time")
      end
    end
---
vim.keymap.set('n', 'T', cycle_sort, opts('Cycle Sort'))

require("nvim-tree").setup({
     sort_by = sort_by_natural,
...
})

[alex-courtis]

Very nice. You can always add more if the need arises.