>   Is there a reason for constructors not to behave like functions? For
> instance, one cannot make a partial application from a constructor:

This is how SML handles constructors, Xavier explained the reasons he chose to depart from this in:

http://caml.inria.fr/pub/ml-archives/caml-list/2001/08/47db53a4b42529708647c9e81183598b.en.html

I think it would be possible to simulate the SML behaviour in OCaml using camlp4 (if you assume that for [type foo = Bar of int] that future unbound references to [bar] are interpreted as [fun x -> bar x] instead of an error)


David