Parameter names in procedural types

[jameshfisher]

In the tutorial there's the example "procedural type":

type
  TCallback = proc(x: int)

proc echoItem(x: int) =
  echo(x)

proc forEach(callback: TCallback) =
  const
    data = [2, 3, 5, 7, 11]
  for d in items(data):
    callback(d)

forEach(echoItem)

Why is it necessary to give parameters names when only declaring a type?
I feel like I should be able to do:

type
  TCallback = proc(int)

Is this in the works?

[Araq]

That is too ambiguous to handle and some consider parameter names a nice form of documentation... However, in the works are type descriptions using the same syntax as expressions:
int * int # short for tuple[a, b: int]
int -> int # short for proc (a: int): int

Hm, now that makes int * int -> int a proc (a: tuple[a,b:int]): int
Damn. Any idea?
--> Discussion in forum (http://force7.de/heimdall/).