[Xotcl] Mixins in XOTcl

[Neil Madden]

On 19 May 2004, at 17:07, Michael Schlenker wrote:

> Kristoffer Lawson wrote:
>
>> On Wed, 19 May 2004, Michael Schlenker wrote:
>>
>>
>>> Its similar in tcl, where you have [info commands] and not a magic
>>> $commands variable as you might have in other languages.
>>>
>>> Using traces it should be possible to provide such an interface if
>>> anyone really wants it.
>>>
>>
>> So what is so problematic about just getting a list, manipulating it 
>> and
>> then setting it back? Seems like a lot of copied effort for what is
>> basically just list manipulation.
>>
> Yep. I refer to Adam and Neil who both wanted to have mutable objects 
> instead of accessor functions.
> Its the usual problem with mutable list objects and the tradional 
> value based list operations in Tcl.

Woah there! I said nothing about mutable objects/values. Mutable 
variables are all that is needed, and they exist already (in fact, you 
have to go an extra step to get immutable variables). The idea is to 
reuse things like [lappend], [linsert], [lreplace] etc, without 
creating lots of [mixin_append], [mixin_replace] etc etc. That's the 
duplication of effort.


Neil.