Re: meta information about structure types

[Bruno H. <br...@cl...>]

Sam wrote:
> >> (let ((c (find-class name)))
> >>   (if c
> >>       (class-direct-slots c)
> >>       (structure-direct-slots name)))
> >
> > This is a hypothetical use case. Doesn't occur in practice. (Where
> > would the 'name' come from?)
>
> I save my objects in text files, writing type and slot names and values.
> Sometimes I use DEFCLASS and sometimes DEFSTRUCT.
> I don't want to have to regenerate all my data if I decide to convert my
> structs to classes.

OK, then you will have to use the  (find-class name nil)  test.
Still, this rare usecase IMO is not worth generating confusion between
classes, class names and structure type names. Clarity of concepts is
important.

> will this work:
> (defstruct foo a b c)
> (class-direct-slots (find-class 'foo))

Sure. After (defstruct foo a b c) either of these will work:
  (class-direct-slots (find-class 'foo))
  (class-slots (find-class 'foo))
  (structure-slots 'foo).

Bruno