[provenance-challenge] Re: Representing collections in OPM -- proposal draft

[Ben Clifford]

On Mon, 22 Jun 2009, David Holland wrote:

> In general, for a type system to stay statically decidable, collection
> types have to have either a fixed size (structures, tuples) or a fixed
> member type (lists, arrays).
> 
> I'm not sure that it's necessary for OPM types to be statically
> decidable. But it may be desirable; in that case we'd want to have
> "tuples" as well as "collections".

If OPM collections are only the second of the above, then Swift would not 
represent its structure types as OPM collections.

I think its still useful to expose the container/member relationship in 
tuples in a way that is sympathetic to OPM collections, because I think 
sometimes you care that some artifact is a part of another artifact 
without caring about the nature of the containment.

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