Tcl Source Code

Hi,

I use ActiveState Tcl 8.6.0.0.295132 Beta 6. The following code:

package require TclOO
oo::class create Mix1 \
{
   variable Mix1_var
   
   constructor {} \
   {
      set Mix1_var 10
      puts "Mix1 constructor: Mix1_var = $Mix1_var."
      next
   }
}

oo::class create C1 \
{
   mixin [oo::copy Mix1 Mix1_copy]
   
   variable C1_var
   
   constructor {} \
   {
      set C1_var 40
      my variable Mix1_var  ;# needed otherwise variable not found (normal behavior)
      puts "C1 constructor: C1_var = $C1_var and Mix1_var = $Mix1_var."
   }
}
C1 create objc1


gives the output:

Mix1 constructor: Mix1_var = 10.
can't read "Mix1_var": no such variable
% puts $errorInfo
can't read "Mix1_var": no such variable
    while executing
"puts "C1 constructor: C1_var = $C1_var and Mix1_var = $Mix1_var.""
    (class "::C1" constructor line 4)
    invoked from within
"next"
    (class "::oo::define::Mix1_copy" constructor line 4)
    invoked from within
"C1 create objc1"

However, if:
mixin [oo::copy Mix1 Mix1_copy]
is replaced by:
mixin Mix1

then it works without an error. So I suspect variables in a mixin not being copied when the mixin class is copied. Please confirm if it is a bug.

Thanks,
Etienne

allow_comments - 1

Fixed with commit of TIP #397 implementation,

Try the attached patch (or look on the development-rfe3485060 of the tcloo project: http://core.tcl.tk/tcloo/) which should now copy variables and procedures. I'd appreciate review; there may be things that should be copied by default which I've forgotten. (Note that non-procedure commands and sub-namespaces will definitely _not_ be copied by default, the former because that's super-hard and the latter because there's now a mechanism for adding it when necessary. I also don't copy traces of any kind.)

It's *possible* that the patch won't apply cleanly to the main Tcl 8.6 trunk right now (well, excluding the ChangeLog entry of course). The codebases are close, but not identical.

File Added - 435627: 3485060.patch