Unit

is the empty type, also represented as () and equivalent to void in C.

=

defn

(Fn [(), ()] Bool) 

                        (= unit-a unit-b)

copy

defn

(Fn [(Ref () a)] ()) 

                        (copy unit-ref)

'copies' a reference to a Unit value. This function just returns a fresh value of type Unit.

prn

defn

(Fn [()] String) 

                        (prn unit)

zero

defn

(Fn [] ()) 

                        (zero)

Returns a fresh value of type Unit (this value performs no side-effects).