[Xotcl] Re: Method inheritance on class side

From: Gustaf Neumann <neumann_at_wu-wien.ac.at>
Date: Wed, 25 Apr 2001 13:14:56 +0200

On Tuesday 24 April 2001 20:25, Kristoffer Lawson wrote:
> On Tue, 24 Apr 2001, Gustaf Neumann wrote:
> Personally I've never had the need for it (per-object procs were fine).
> Usually I'd always want to keep a language as simple as possible. Of
> course if I had a need for such a structure then maybe I would change
> my stance, but until it becomes very common I'm probably content with
> the current system.

 well, here is a quite a short and simple solution that might be sufficient
 for most situations:

====================================================================================
Class InheritClassProc
InheritClassProc instproc unknown {m args} {
  foreach c [[self] info heritage] {
    if {[info command ${c}::$m] != ""} {return [eval $c $m $args]}
  }
  next
}
Class instmixin InheritClassProc
====================================================================================

 one can add a ...if {![.. ismetaclass ...]} to avoid its call on the
 creation of classes.
 To test it in the originally posted problem, the following example calls
 for "B test ..." the proc of A, and creates a new object for "B test".

==================================================
Class A
A proc test {x y} {
  expr {$x*$y}
}
Class B -superclass A
puts result=[B test 47 11]
puts result=[B test1]
==================================================

 If you have a speed sensitive program, or you do not want to globber
 the space of object names, i would recommend to invoke the
 create method explizitly like "B create test1", or to create an
 instance of B named "test", use "B create test"

best regards
-gustaf