[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Fundamental design flaws

> Bradd W. Szonye wrote:
>> No, it's a flaw in the design. You distinguish lists from alists
>> according to content. You'll have isomorphism problems whenever the
>> content of a list happens to match the structure of an alist. The only
>> way to avoid that is to eliminate support for primitive alists -- which
>> means eliminating support for one of the most common Scheme collections.

scgmille@xxxxxxxxxxxxxxxxxx wrote:
> No we don't.  Taylor can attest to that.  That was a bug in the
> implementation at the time, it wasn't a problem previous to that
> version, and isn't a problem now.

How do the generic procedures know whether '((a . 1) (b . 2)) is a list
or an alist? If it's based on content, you have isomorphism issues to
resolve. If you're now using something like a record type for alists,
then you're not really handling primitive alists.
Bradd W. Szonye