str:find

For some reason, sString:find( word ) is returning a single value instead of two… as it is supposed to according to http://lua-users.org/wiki/StringLibraryTutorial. Is it simply returning the start of the word (from which I can find the rest of it), or is it doing something else?

function zip( sString )
	local len = #sString
	for i = 16, 6, -1 do
		for x = 1, i do
			for word in sString:sub( x ):gmatch( string.rep( ".", i ) ) do
				local s, e = sString:find( word )
				local replace = "<"..s..","..e..">"
				sString = sString:gsub( word, replace )
				sString = sString:sub( 1, x )..word..sString:sub( x + #replace )
				sString = sString:gsub( word:reverse(), "<"..e..","..s..">" )
				sleep( 0 )
			end
		end
	end
	return sString, len - #sString
end

Also, what is the best way of getting a "tree" for a number? here's an example, since I'm not sure what it's really called:

   16
  2  8
 2  2  4
2  2  2  2
--#and another one
  27
 3  9
3  3  3

The "tree" you are talking about is a number's prime factors. Try something like this:

function primeFactors(n)
  i = 2
  while n > 1 do
    if n % i == 0 then
      n = n/i
      print(i)
      i = 2
    else
      i = i + 1
    end
  end
end

primeFactors(84)

would output

2
2
3
7

EDIT: Explanation:

What the function does is starts at the first prime (2) then increases it until it finds the first prime factor, then starts again with the number divided by it. This could easily be done recursively but hopefully this was easier to follow. It would also be fairly easy to amend so that it prints it in a tree form.

Thanks, that will help me a lot.