Alex Shinn scripsit:

> I think strong typing with unique objects is better here.  They are
> less ambiguous, more efficient for many of the utilities, and as you
> say can be used to access the other members of the enum-set.

I grant these advantages, but the simplicity and convenience of symbols
are real advantages too.  I'm trying to work out a design in which
either symbols or unique objects wrapping symbols can be used.

> A common pattern I use in Chibi for data structures is to have a
> base library with just the type predicate and -contains?  utility,
> and constructors go in a separate library.  Thus other libraries
> could provide APIs that allow sets as arguments for convenience,
> without themselves incurring any real load overhead.

I don't really understand this use case.  If you accept sets as
arguments, what do you want to be able to do with them?

--
How they ever reached any conclusion at all     <xxxxxx@ccil.org>
is starkly unknowable to the human mind.        http://www.ccil.org/~cowan
        --"Backstage Lensman", Randall Garrett