function file_exists(file)
	local f = io.open(file, "rb")
	if f then f:close() end
	return f ~= nil
end

function lines_from(file)
	if not file_exists(file) then return {} end
	local lines = {}
	for line in io.lines(file) do
		lines[#lines + 1] = line
	end
	return lines
end

function table_contains_element(table, element)
	for key, value in pairs(table) do
		if value == element then
			return true
		end
	end
	return false
end

function table_find_word(table, word)
	for key,value in ipairs(table) do
		for w in string.gmatch(value,"%a+") do
			if w == word then 
				return true
			end
		end
	end
	return false
end