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Re: Fundamental design flaws

This page is part of the web mail archives of SRFI 44 from before July 7th, 2015. The new archives for SRFI 44 contain all messages, not just those from before July 7th, 2015.

> 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