func all_nums(nums:[Int] -> Text)
	result := ""
	for num in nums
		result ++= "$num,"
	else
		return "EMPTY"
	return result

func labeled_nums(nums:[Int] -> Text)
	result := ""
	for i,num in nums
		result ++= "$i:$num,"
	else
		return "EMPTY"
	return result

func table_str(t:{Text:Text} -> Text)
	str := ""
	for k,v in t
		str ++= "$k:$v,"
	else return "EMPTY"
	return str

func table_key_str(t:{Text:Text} -> Text)
	str := ""
	for k in t
		str ++= "$k,"
	else return "EMPTY"
	return str

func main()
	assert all_nums([10,20,30]) == "10,20,30,"
	assert all_nums([]) == "EMPTY"

	assert labeled_nums([10,20,30]) == "1:10,2:20,3:30,"
	assert labeled_nums([]) == "EMPTY"

	>> t := {"key1": "value1", "key2": "value2"}
	assert table_str(t) == "key1:value1,key2:value2,"
	assert table_str({}) == "EMPTY"

	assert table_key_str(t) == "key1,key2,"