DOKK / manpages / debian 11 / tcl8.6-doc / oo_copy.3tcl.en
copy(3tcl) TclOO Commands copy(3tcl) 







oo::copy - create copies of objects and classes








package require TclOO
oo::copy sourceObject ?targetObject? ?targetNamespace?










The oo::copy command creates a copy of an object or class.
    It takes the name of the object or class to be copied, sourceObject,
    and optionally the name of the object or class to create,
    targetObject, which will be resolved relative to the current
    namespace if not an absolute qualified name and targetNamespace which
    is the name of the namespace that will hold the internal state of the object
    (my command, etc.); it must not refer to an existing
    namespace. If either targetObject or targetNamespace is
    omitted or is given as the empty string, a new name is chosen. Names, unless
    specified, are chosen with the same algorithm used by the new method
    of oo::class. The copied object will be of the same class as the
    source object, and will have all its per-object methods copied. If it is a
    class, it will also have all the class methods in the class copied, but it
    will not have any of its instances copied.


After the targetObject has been created and all definitions
    of its configuration (e.g., methods, filters, mixins) copied, the
    <cloned> method of targetObject will be invoked, to
    allow for customization of the created object such as installing related
    variable traces. The only argument given will be sourceObject. The
    default implementation of this method (in oo::object) just copies the
    procedures and variables in the namespace of sourceObject to the
    namespace of targetObject. If this method call does not return a
    result that is successful (i.e., an error or other kind of exception) then
    the targetObject will be deleted and an error returned.


The result of the oo::copy command will be the
    fully-qualified name of the new object or class.








This example creates an object, copies it, modifies the source
    object, and then demonstrates that the copied object is indeed a copy.






oo::object create src
oo::objdefine src method msg {} {puts foo}
oo::copy src dst
oo::objdefine src method msg {} {puts bar}
src msg              → prints "bar"
dst msg              → prints "foo"










oo::class(3tcl), oo::define(3tcl), oo::object(3tcl)








clone, copy, duplication, object







  

    0.1
    TclOO