Re: Something like an array (list) of a class

[Decebal <CLDWesterhof@gmail.com>]

On 13 apr, 10:53, Decebal <CLDWester...@gmail.com> wrote:
> On Apr 12, 10:03 am, thierry.volpia...@gmail.com wrote:
>
> > There is no class in elisp but you have defstruct (be sure to require 'cl)
>
> Looks like it that it does what I want. I want only the last field
> mutable and the other fields parameterized. That is possible if I
> understand it correctly.

I tried the following:
    (require 'cl)

    (defstruct
      (ModeLine
       (:constructor nil)
       (:constructor new-ModeLine (type description display function))
       )
      (type        :read-only t)
      (description :read-only t)
      (display     :read-only t)
      (function    :read-only t)
      )

    (setq e (new-ModeLine
             "word"
             "Display number of words"
             "W"
             'buffer-count-words
             )
          )

This seems to do what I want.
A few questions remain:
- Is there a way to make sure that type, description and display are
of type string and function of type  function?
- Is there a way to make sure that none of the elements are empty?
- I would like to have a list (or other data structure) filled with
only objects of type ModeLine. What is the best way to do this?
- Is it possible to have all type and display values distinct?