Re: [Chicken-users] SRFI-9 vs. define-record vs. (copy)

[felix]

address@hidden wrote:
> Currently SRFI-9 records and (define-record) records are
> disjoint. Could they be made the same? I'd really love to have
> (define-record-printer) for SRFI-9 records :-)

The code generated by `define-record' is more efficient than
the SRFI-9 stuff. I have to take a deeper look, but I'm not
sure wether it is possible to make the underlying machinery
the same without a) making Chicken's records slower, and
b) violating SRFI-9.

> On the topic of records, the (copy) function is *too* deep - it copies
> the record type as well as the record value!
>
>         (define-record x y)
>         (define a (make-x 1))
>         (define b (copy a))
>
>         a ==> #<x>
>         b ==> #<x>     ;; but it's a *different* x
>
>         (x-y a) ==> 1
>         (x-y b) ==> error
>
>         (x? a) ==> #t
>         (x? b) ==> #f
>
> Any suggestions on how this might be avoided?

The `copy' procedure (as much of the stuff in the `lolevel'
unit) should be taken with a grain of salt: it's more intended
for low-level hacks (like copying data from non-GC'd memory
back into the heap). I really should have taken a less generic
name. The problem here is that the symbol is copied too and
so doesn't keep it's uniqueness (I think there is something
in the manual about this). I will rename `copy' and introduce
a decent generic copying routine.


cheers,
felix