TOOLS/autoload.lua: implement natural sorting

TOOLS/lua/autoload.lua

@@ -53,6 +53,37 @@ table.filter = function(t, iter)
     end
 end
 
+-- splitbynum and alnumcomp from alphanum.lua (C) Andre Bogus
+-- Released under the MIT License
+-- http://www.davekoelle.com/files/alphanum.lua
+
+-- split a string into a table of number and string values
+function splitbynum(s)
+    local result = {}
+    for x, y in (s or ""):gmatch("(%d*)(%D*)") do
+        if x ~= "" then table.insert(result, tonumber(x)) end
+        if y ~= "" then table.insert(result, y) end
+    end
+    return result
+end
+
+function clean_key(k)
+    k = (' '..k..' '):gsub("%s+", " "):sub(2, -2):lower()
+    return splitbynum(k)
+end
+
+-- compare two strings
+function alnumcomp(x, y)
+    local xt, yt = clean_key(x), clean_key(y)
+    for i = 1, math.min(#xt, #yt) do
+        local xe, ye = xt[i], yt[i]
+        if type(xe) == "string" then ye = tostring(ye)
+        elseif type(ye) == "string" then xe = tostring(xe) end
+        if xe ~= ye then return xe < ye end
+    end
+    return #xt < #yt
+end
+
 function find_and_add_entries()
     local path = mp.get_property("path", "")
     local dir, filename = mputils.split_path(path)
@@ -81,15 +112,7 @@ function find_and_add_entries()
         end
         return EXTENSIONS[string.lower(ext)]
     end)
-    table.sort(files, function (a, b)
-        local len = string.len(a) - string.len(b)
-        if len ~= 0 then -- case for ordering filename ending with such as X.Y.Z
-            local ext = string.len(get_extension(a)) + 1
-            a = string.sub(a, 1, -ext)
-            b = string.sub(b, 1, -ext)
-        end
-        return string.lower(a) < string.lower(b)
-    end)
+    table.sort(files, alnumcomp)
 
     if dir == "." then
         dir = ""