New CAT call

Revision as of 12:04, 27 October 2006 by Konradm (Talk | contribs) (Introduction)

Introduction

The ECMA standard introduces a new solution to the CAT call problem. Covariant redefinition of a formal argument is only possible to a detachable type:

class A
feature
   f (a: ANY) do end
end
class B1
inherit A redefine f end
feature
   f (a: STRING) do end   -- not valid
end
class B2
inherit A redefine f end
feature
   f (a: ?STRING) do end   -- valid
end

This wiki discusses some of concerns related to this solution.

Detachable type