On Tue, Sep 2, 2008 at 10:26 AM, David Baelde <david.baelde@gmail.com> wrote:
> This amouns to provide a cast from the abstract type to the function
> type, while keeping the liberty on how it's implemented.

If you want even more implementation liberty, you should consider
making the internal "token collection" type abstract : you use a list
for now, but might want to use Streams or lazy lists or what not
someday.

That would give something like that :
module Parser : sig
  type ('a,'tok) t
  type 'tok input
  val token : ('tok -> 'a option) -> ('a,'tok) t
  val apply : ('a,'tok) t -> 'tok input -> ('a * 'tok input)
  val input_of_list : 'tok list -> 'tok input
end = [...]