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

>> all_nums([10,20,30])
= "10,20,30,"
>> all_nums([:Int])
= "EMPTY"

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

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

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

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

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

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