Files
Mush-Soundpack/cosmic rage/lua/alphanum.lua
2025-07-01 23:28:00 +03:00

81 lines
2.1 KiB
Lua

-- alphanum.lua
--
-- Adapted somewhat from: http://www.davekoelle.com/files/alphanum.lua
-- Also see: http://www.davekoelle.com/alphanum.html
--
-- Implements a sort function that does a more "human readable" sort order.
-- It breaks the sort strings into "chunks" and then compares each one naturally,
-- depending on whether it is a string or a number (eg. z9.doc compares less than z20.doc)
-- It also does a case-insensitive compare (so "nick" and "Nick" come out together).
-- See also: http://www.gammon.com.au/forum/?id=8698
--[[
Example:
require "alphanum"
t={
"z18.doc","z19.doc","z2.doc","z16.doc","z17.doc",
"z1.doc","z101.doc","z102.doc","z11.doc","z12.doc",
"z13.doc","z14.doc","z15.doc","z20.doc","z3.doc",
"z4.doc","z5.doc","z6.doc","z10.doc","z100.doc",
"z7.doc","z8.doc","z9.doc", "Z9A.doc",
}
table.sort(t, alphanum (t))
for i=1, #t do
print(t[i])
end
--]]
function alphanum (t)
assert (type (t) == "table", "Must pass table to be sorted to alphanum")
local function chunkString(str)
local c = {}
for a, b in tostring (str):gmatch("(%d*)(%D*)") do
if a ~= "" then c[#c+1] = tonumber(a) end
if b ~= "" then c[#c+1] = b end
end
return c
end
local chunks = {}
-- build temporary table of the keys
for i=1, #t do
chunks [t [i]] = chunkString (t [i])
end
return function (a, b) -- return our sort comparison function
-- lookup chunked information from previously-built table
local achunks = chunks [a]
local bchunks = chunks [b]
for i = 1, math.min (#achunks, #bchunks) do
local as, bs = achunks [i], bchunks [i]
-- if one is a string, make them both strings
if type (as) == "string" or type (bs) == "string" then
as = (tostring (as)):upper ()
bs = (tostring (bs)):upper ()
end -- at least one is a string
-- if they are equal, move onto the next chunk
if as ~= bs then
return as < bs
end -- if
end -- for each chunk
-- still equal? the one with fewer chunks compares less
return #achunks < #bchunks
end -- sort function
end -- alphanum
return alphanum