[atombender]

It's not inconsistent, just terser. You could say that "fn" declares a function by name; the type of foo is int -> str.

In Haskell, this is written:

  foo :: int -> str

Of course, Haskell is based on lambda calculus, so multiple arguments are just a generalization of partial function application:

  foo :: int -> int -> str

(A function taking two int arguments and returning a string, which is indistinguishable from a function that takes a single int and returns a function that takes a single int and returns a string.)

[tapirl]

Ah, looks both have their own rationality. ":" is ok for single-value returns. AS3 also uses ":".

The Haskell language looks interesting. Maybe I should spend some time to study it.