[Miky]

In both Gluon and Haskell, functions without arguments can be represented as functions over the unit type:

  f: () -> SomeType

which can be called via:

  f ()

There are examples of this in the Gluon book (http://gluon-lang.org/book/syntax-and-semantics.html). There are no syntax-related difficulties at all here. This is also how it's done in OCaml and related languages.

(Note: This is (basically) useless in Haskell, since laziness makes this have the same semantics as a constant:

  f :: SomeType

But since Gluon is strict, there's a pretty important difference between the two.)