flat name space for pkg names

[DALTON FHL (on ERCC DEC-10) <J.Dalton%edxa@ucl-cs.arpa>]

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[This is not a proposal for changing Common Lisp; it is just a request for
information.  You may want to reply just to me rather than to the mailing
list.]

We're curently looking into ways of adding "modules" to Prolog, where
modules are just some way of having multiple name spaces.  One possible
model for at least some parts of this is Common Lisp packages (packages
rather than Common Lisp modules).  But, whenever they are mentioned,
someone always raises the objection that there can be name conflicts
between package names.  (Suppose two programs are to be combined and both
have some procedures packaged up in a "graph" package.  The "graph" packages
meant to be independent, but they clash.)

My question, then, is this: why was a flat name space for package names
chosen for Common Lisp instead of one that allowed subpackages?  And
how are package conflicts of the kind mentioned above meant to be resolved?

Cheers,
Jeff Dalton
AIAI, University of Edinburgh

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