> Bear wrote:
>> SRFI-44 does not need to depend on any OO framework or library to get
>> dynamic dispatch based on the collection type .... Therefore consider
>> as a possibility, a vector a few dozen elements long.  Let the first
>> element, at index zero, contain a symbol .... And it'll work.
>> Immediately.  And it'll be totally clear to everybody how to write
>> collections that this interface can use.

Anton van Straaten wrote:
> This could make a nice reference implementation.  It's not completely
> clear to me whether you're also suggesting that this should be
> something that the spec requires of implementations, though.  I don't
> see the need for it in implementations that already provide a generic
> dispatch mechanism - it would only add overhead.

I think the spec needs some way for implementors to portably "hook into"
the dispatch system. Otherwise, users will have a hard time extending
the set of collections, which defeats the purpose of having the generic
interfaces. They'll need to rely on the internals of the local SRFI-44
implementation. The situation is worse for independent library authors,
because they'll have one more portability issue to deal with.

On the one hand, I really don't think it's a good idea to tie the
interface down to a specific delegation mechanism. On the other hand,
you'll have these portability problems if you don't supply *some* method
of extending the set of delegations.
--
Bradd W. Szonye
http://www.szonye.com/bradd