Bug in Intersect, Questions about Difference and Union about moses HOT 1 CLOSED

require('pl')
local m = require('moses')

utils.printf("%s\n","That feels better")
local lfw = data.read('lfw_modules.tab')
local lp = data.read('luaplus_modules.tab')

local function tableize(func)
	local t = {}
	for i in func do
		t[#t+1] = string.lower(i)
	end
	return t
end

local W1 = tableize(lfw:select('NAME'))
local P1 = tableize(lp:select('NAME'))

--intersection to get all  matches
-- Union to get duplicate free list
-- difference -- gets the non matchs

local diff = m.difference(W1,P1)
local union = m.union(W1,P1)
local intersect = m.intersection(W1,P1)

file.write('wp_diff.txt', pretty.write(diff)) 
file.write('wp_union.txt', pretty.write(union))
file.write('wp_intersect.txt', pretty.write(intersect))