Eli Zaretskii <eliz@gnu.org> writes:

> Thanks, but why do we need to make the value of this mode-line-element
> property be the element itself?  Why not give it some simple value,
> like the ordinal number of the element (which should be incremented
> whenever we process another element)?  So we could call this property
> mode-line-elt-number and assign the elements values 1, 2, 3, etc.

Is casting the 'Lisp_Object' to a number acceptable here? Please have a
look at the updated patch.

I tried an incremental counter but gave up. Because
'display_mode_element' could be called recursively, we may have to
change its signature or introduce a new global variable. That feels a
bit less clean to me.

> I'm concerned that having the elements themselves be values will
> prevent them from being GC'd, which might increase the memory
> pressure.  By contrast, fixnums are immediate values that don't need
> to be GC'ed, and the element itself will not have any references after
> the mode line is processed.

I thought all objects would be GC'd. Since fixnums are not, I guess now
we do not need to remove the text property before displaying the string?
Please let me know what you think and I will update the patch if needed.