Re: "Must instantiate controlled types at library level." Why?

[Georg Bauhaus <sb463ba@l1-hrz.uni-duisburg.de>]

Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:

: Technically what is needed is abstract array interfaces, abstract
: index types, discriminants for all types, an ability to put type tags
: and disctiminants in a dope separate from the value, pure compile-time
: subprograms to evaluate does, supertypes. Give me that, then ask (:-))


  function item_at (a: Array'type; pos: Index'type) return Element'type;

Like this?
Is this efficient? How many checks are needed at run time (in the
presence of separate compilation)? How do you get hold of plain
basic types?

Anyway, there are two articles on "Genericity versus Inheritance"
by Meyer (1986) and Seidewitz (1994) that I'll have to study first,
I guess.


-- Georg