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Re: [Scheme-reports] Formal Comment: R7RS 'eqv?' cannot be used for reliable memoization

Ray Dillinger scripsit:

> In Lispy languages, we tend to fake both by using lists.  But that is,
> IMO, not quite right.  Sometimes the difference is important and we'd
> like to know more about the meaning conveyed.

Lists convey their contents, and they order them too, which is sometimes
relevant and sometimes not.  But they don't say what to do with those
contents, or what they mean.  That's inherent in general purpose data
structures: they are not *for* anything in particular, and so are both
flexible and opaque -- flexible in use, opaque in meaning.

> As Mark Weaver pointed out, if you have multivalences, you will
> usually be required to select *one* of them because some client
> somewhere won't want to know their question had more than one answer.
> And in fact, will demand to be kept in ignorance, treating additional
> correct answers as a bug.

When I google "To be or not to be", I don't actually care which web page
I look at: any will do.

John Cowan   cowan@x    http://ccil.org/~cowan
The known is finite, the unknown infinite; intellectually we stand
on an islet in the midst of an illimitable ocean of inexplicability.
Our business in every generation is to reclaim a little more land,
to add something to the extent and the solidity of our possessions.
        --Thomas Henry Huxley

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