Deletes a class object OR a class definition.

See [itcl::class] for simple class examples. itcl::delete releases the memory held in the instance.

Deletion automatically calls the destructor method, where any subsidiary tidying up is performed.

  package require Itcl
  itcl::class helloworld {
    variable next "" ;# to form a linked list of helloworlds
    constructor {} {puts "helloworld object $this has been created"}
    destructor { puts "helloworld object $this deleted"
        if {$next!=""} { itcl::delete object $next } }

    method addtolist {newhw} { if {$next==""} { set next $newhw
        } else { $next addtolist $newhw }
    }
    method list {} { puts "$this has next $next"
        if {$next!=""} { $next list } }
  }
  helloworld h1
  helloworld h2
  helloworld h3
  helloworld h4
  h1 addtolist h2
  h1 addtolist h3
  h1 addtolist h4
  # this will print the entire list from h1 to h4.
  h1 list
  # this deletes h1 then h2 (which deletes h3, which deletes h4)
  itcl::delete object h1  

The last statement deletes all objects as they are in the list. Then h1 h2 h3 and h4 will be undefined, beware. The output from the fragment above is:

  helloworld object ::h1 has been created
  helloworld object ::h2 has been created
  helloworld object ::h3 has been created
  helloworld object ::h4 has been created

  ::h1 has next h2
  ::h2 has next h3
  ::h3 has next h4
  ::h4 has next 
 
  helloworld object ::h1 deleted
  helloworld object ::h2 deleted
  helloworld object ::h3 deleted
  helloworld object ::h4 deleted

The command

  itcl::delete class helloworld
will prevent any further helloworld objects being created, and deletes all instances of helloworld object.
  helloworld h1
  helloworld h2
  itcl::delete class helloworld

will delete h1, h2 and the class definition, so you will see:
  >> helloworld object ::h2 deleted
  >> helloworld object ::h1 deleted
  (bin) 19 % helloworld h4
  invalid command name "helloworld"

[GWM]


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[Category Itcl] [Category Command] [Category Object Orientation]