The nothing type

To represent the lack of a value, Ranty has the nothing type, which has only one possible value, represented in Ranty by the literal <> (referred to as the "nothing literal").

The nothing type acts as a placeholder value or indicator that no value is provided or needed.

Printing a value of type nothing will have no effect on the output.

# The nothing literal prints nothing.
[type: <>]  # nothing

# An empty expression also prints nothing.
[type: ]  # nothing

Uses for the nothing literal

Even though an empty expression prints the same nothing value as <>, using <> explicitly can change program behavior in some cases; specifically, collection initializers.

For example, this empty list initializer will have a length of 0:

[len: (:)] # 0

If we want to initialize the list with a single entry containing nothing, we can use the nothing literal to make this distinction:

[len: (: <>)] # 1

This also works for specifying a final empty entry in a list or tuple, where Ranty would otherwise ignore the trailing ;:

[len: (1;)]     # 1
[len: (1; <>)]  # 2