CoordinateSpace

[Mark S. Miller <mark>]

Date: Mon, 23 Oct 89 14:21:20 PDT
   From: heh (Hugh Hoover)

   ...(set vs. bag)... Tables? Multiple values for a single key.

     The current table implementations are 1:1.
   The introduce and replace protocol are specific about being 1:1, so how do
   we semantically justify a table where store allows multiple values for a key?

We are replaying here an aspect of the evolution of the semantics for
orgls.  By analogy with that experience, I'd say that a multi-valued
mapping is a bad foundational abstraction.  You can get much the same
effect by generating unique keys as positions whose only purpose is to
keep multiple values from being at the same place.  This results in
the ability to subset and recombine such tables in a better behaved
fashion.  Admittedly, this argument may be specific to Multi-Orgls.