Hi Sergey,
The improved version does still suffer from the bug caused by appending
(99-#z): "012b" > "12a", whereas it should be "012b" > "12a".
In case "#t == 1" you shouldn't append #r, because "0.11" < "0.2".
Thank you for pointing this out (I think you meant "012b" < "12a" in
the first comparison). Here is a better solution that fixes both of
these issues (although it's also not perfect in dealing with leading
zeroes):
function alphanumsort(o)
local function padnum(d) local dec, n = string.match(d, "(%.?)0*(.+)")
return #dec > 0 and ("%.12f"):format(d) or
("%s%03d%s"):format(dec, #n, n) end
table.sort(o, function(a,b)
return tostring(a):gsub("%.?%d+",padnum)..("%3d"):format(#b)
< tostring(b):gsub("%.?%d+",padnum)..("%3d"):format(#a) end)
return o
end
This also sorts decimal numbers:
Abc 0.100a
Abc 0.1b
Abc 0.11
Abc 0.2
I updated the page to capture various solutions we discussed (from
simplest to the best so far) as well as their results:
http://notebook.kulchenko.com/algorithms/alphanumeric-natural-sorting-for-humans-in-lua.
"." < " " -- you'll face the ("." > "/") bug instead
I didn't quite get this comment...
I doubt the real numbers case has a use though :)
That I agree with ;).
Paul.
On Sat, Aug 25, 2012 at 6:46 PM, GrayFace <sergroj@mail.ru> wrote:
On 26.08.2012 8:09, Paul K wrote:
Agree; I just sent an improved version that shouldn't suffer from this
problem.
I see we used the same idea of first comparing the length of numbers and
then using lexicographical comparison of numbers.
The improved version does still suffer from the bug caused by appending
(99-#z): "012b" > "12a", whereas it should be "012b" > "12a".
In case "#t == 1" you shouldn't append #r,_because "0.11" < "0.2"_.
You made me also think about the real numbers case. My attempt at
implementing it has these bugs so far:
"." < " " -- you'll face the ("." > "/") bug instead
"0.100a" > "0.1b"
I doubt the real numbers case has a use though :)
--
Best regards,
Sergey Rozhenko mailto:sergroj@mail.ru
