TIP #473: ALLOW A DEFINED TARGET NAMESPACE IN OO::COPY 
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 Version:      $Revision: 1.4 $
 Author:       Donal Fellows <dkf_at_users.sf.net>
 State:        Final
 Type:         Project
 Tcl-Version:  8.6.7
 Vote:         Done
 Created:      Tuesday, 06 June 2017
 URL:          https://tip.tcl-lang.org473.html
 Post-History: 

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 ABSTRACT 
==========

 This TIP adds functionality to *oo::copy* to allow the created copy to 
 have a defined namespace, much as *oo::class*'s *createWithNamespace* 
 method allows such a namespace to be given on normal object creation. 

 RATIONALE 
===========

 Due to an oversight, the *oo::copy* command is missing the ability to 
 have an explicit namespace name specified to use as the instance 
 namespace of the target object. It was always intended to have this 
 (and the functionality is there in the C API), but it was omitted from 
 the Tcl-level interface. 

 Having this capability allows objects to be used as factories for 
 namespaces, which is in many ways an inversion of the way that TclOO 
 was designed (with namespaces as the basis for objects). It was 
 requested by Nathan Coulter as a way to enable more complex behaviour 
 in Rivet and NaviServer. See Tcl Issue dd3b844fda 
 [<URL:http://core.tcl.tk/tcl/tktview/dd3b844fdabdeae5fcb0>] for more 
 information. 

 PROPOSED CHANGE 
=================

 I propose to add one more optional argument to *oo::copy*, 
 /targetNamespace/, that if provided and non-empty will be the name of a 
 namespace (resolved relative to the current namespace if not an 
 absolute name) that will be the name of the newly created target 
 object's instance namespace. The named namespace must not already 
 exist. Note that specifying the /targetObject/ as the empty string will 
 cause the object's command to be automatically chosen. 

       *oo::copy* /sourceObject/ ?/targetObject/? ?/targetNamespace/? 

 The meaning of the result of the command is unchanged. 

 IMPLEMENTATION 
================

 See the oo-copy-ns branch. 
 [<URL:http://core.tcl.tk/tcl/timeline?r=oo-copy-ns>] 

 COPYRIGHT 
===========

 This document has been placed in the public domain. 

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