Whoa, the Dotty extension method syntax has gotten all goofy: 
def (c: Circle) circumference: Double
instead of the C# style
def circumference(this c: Circle) : Double
-
This Tweet is unavailable.
-
This Tweet is unavailable.
-
This Tweet is unavailable.
-
I don't see it as "yet another way to define functions" because it's defining extension methods, which are semantically different. Having them not look like ordinary methods (and not having a secondary way to call them) is a positive.
As for "converting" it to a function, it is still going to be "just a function", but you'll need to write the lambda which constructs that function. That will probably look like a callsite application, so it will mirror the definition, too. Is that what you meant?