Emptiness Method Check
It might be useful to have a check to indicate emptiness of a variable. If the result of this method is true, return "1", else return nothing. Or should we return "0" as well if false? The benefit of not returning a value for a false verdict is that the test
command defaults to -n
when no flags are specified, which makes the following possible:
if test $is_empty(string)
echo true
else
echo false;
end
if test @is_empty(array)
echo true
else
echo false;
end