Re: Metaclass & McCLIM revisited
"Yuri Davidovsky (as work at disclosure dot ie)" <[email protected]>
| Newsgroups | gmane.lisp.lispworks.general |
|---|---|
| Message-ID | <[email protected]> |
> On 29 Jan 2026, at 19:16, Paul Werkowski (as pw at snoopy dot qozzy dot com) <[email protected]> wrote: > > The main problem was the inclusion in the source code a new file, dynamic-vars.lisp, which introduced a CLOS class with a non standard metaclass, CLASS-WITH-DYNAMIC-SLOTS. > This was to implement an object slot scheme in which the slot-value of specified slots were initialized to be an instance of class DYNAMIC-VARIABLE which would contain the actual value of interest. I did not understand a lot of the email, mainly due to the fact that I rarely use CLOS, let alone MOP and the goal and the purpose of the things discussed eluded me. So I would start from asking what is the purpose of this dynamic variable binding to an object slot. As I understand it, you create a custom object instance and sort of fuse a dynamic variable into it? So when you access a slot value, you are actually accessing the value of the dynamic variable that the slot points to? This is what I understood. But I did not quite get the purpose of it. Is the purpose that you will get a different value in the slot depending on the package you are using the class in? If so, why can’t you simply access the dynamic variable directly, why do you need this additional level of indirection? Or was it something that the library did that you did not need, but it could not compile without that thing fixed? And also, you use a term ‘thread local slots’ but I am not sure what it means either. Or is it just a different name of the same thing of dynamic vars assigned to object slots? _______________________________________________ Lisp Hug - the mailing list for LispWorks users [email protected] http://www.lispworks.com/support/lisp-hug.html