Re: RFC: User-defined pseudovectors

[Stefan Monnier <monnier@iro.umontreal.ca>]

> that the need increases.  Most other languages have some kind of
> user-defined record types, and they are used quite liberally.

I'm not necessarily opposed to user-defined record types, but if
cl-defstruct is not sufficient and C-level changes are required, then
I'd hope for the new code to provide more exciting features than just
"vectorp returns nil".

>>> (cond
>>> ((vectorp x)   (frob-vector x))
>>> ((foop x)      (frob-foo x))))
>> So similarly the above code should check `foop' before `vectorp'.
> That would still fail for the input [foo].

Not sure if it should be considered as a bug, tho (it depends on what
was the intention of the caller.  IOW: would she have passed #%[foo] or
[foo] in your version of Emacs?).  Especially for cl-defstruct objects
where you'd need to pass [cl-defstruct-foo].  But if that's a problem,
you can use a more unique object as tag, e.g. an uninterned symbol.


        Stefan