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Re: Edit a cl-struct by copy, or, slot-value for cl-structs
From: |
Yuan Fu |
Subject: |
Re: Edit a cl-struct by copy, or, slot-value for cl-structs |
Date: |
Fri, 29 Oct 2021 14:46:45 -0700 |
> On Oct 29, 2021, at 12:15 PM, Stefan Monnier via Users list for the GNU Emacs
> text editor <help-gnu-emacs@gnu.org> wrote:
>
>> (mapcar #'cl--slot-descriptor-name
>> (cl--struct-class-slots (get (type-of obj) 'cl--class)))
>>
>> But I can’t get any further as I can’t find any generic getter and
>> setter for cl-struct’s. Something like slot-value. So close!
>
> The position of the slot descriptor in `cl--struct-class-slots` mirrors the
> position of the slot in the actual objet, so you just need `aref/aset`.
Ah, silly me!
>
> It would also make a lot of sense to replace/extend the useless
> `:copier` thingy of `cl-defstruct` with something like the
> `:constructor`, so you could say
>
> (cl-defstruct (my-foo
> (:copier my-foo-with)
> (:copier my-foo-with-a (b a)))
> a b c)
>
> and then use (my-foo-with foo :c 42) and (my-foo-with-a foo 153 "42”)
That’s cool. But my lazy fingers like better to write a single function and use
it for everything ;-)
Yuan
- Edit a cl-struct by copy, or, slot-value for cl-structs, Yuan Fu, 2021/10/29
- Re: Edit a cl-struct by copy, or, slot-value for cl-structs, Emanuel Berg, 2021/10/29
- Re: Edit a cl-struct by copy, or, slot-value for cl-structs, Stefan Monnier, 2021/10/29
- Re: Edit a cl-struct by copy, or, slot-value for cl-structs,
Yuan Fu <=
- Re: Edit a cl-struct by copy, or, slot-value for cl-structs, Michael Heerdegen, 2021/10/29