Re: User-defined record types

[Lars Brinkhoff]

Stefan Monnier <address@hidden> writes:
>> - If you don't pass the :type option to cl-defstruct, you get a
>> cl-struct-FOO type tag in slot 0.
>
> That's right.  And this symbol's value is the class object.
> The same holds for EIEIO.
>
> These are the main candidates for use of the new `record` type.

Yes, at first I tried to make cl-deftype do this by default.  But I ran
into problems in cl-preloaded.el and cl-generic.el.

>> - If you pass :type but not :named, you don't get any type tag.
>
> And those should not use `record` but `vector` or `list`
> depending on the :type that was specified.
>
>> - If you pass :type and :named, you get a type tag in slot 0, which is
>> the same symbol as the struct name.
>
> But again, these shouldn't use `record`.

Right, I just wanted to list all possible variations to gain some
understanding.  For example, I don't know if it makes a difference if
the slot 0 type tag has the form cl-struct-FOO as is the default, or
just FOO as when you specify :type.  But now I know there might be.