**DRAFT** issue MACRO-ENVIRONMENT-EXTENT, version 3

[Barry Margolin <barmar@Think.COM>]

I'm not really sure how I feel about this issue.  My gut reaction is
that only dynamic extent should really be necessary.

In any case, if DYNAMIC-WITH-COPIER is seriously proposed, I'd prefer a
different name for the function.  A function COPY-xxx that is permitted
to return its argument instead of a copy seems poorly named (do we have
any other such functions?).  COPY-ENVIRONMENT-IF-NECESSARY is better,
since it explicitly mentions the conditional nature, but it's pretty
long (but how often will it be used?).  INDEFINITE-EXTENT-ENVIRONMENT is
also a good name, but just as long.

Maybe a declaration is the right thing for this, as in the
DYNAMIC-EXTENT cleanup proposal.  I'd prefer dynamic extent to be the
default, with a declaration to request indefinite extent since that is
less commonly needed.  Implementations may ignore the declaration, but
they must then always provide indefinite extent.  A simpler proposal
would be to make indefinite extent the default, and then the
DYNAMIC-EXTENT cleanup proposal would permit programmers to explicitly
declare dynamic environments.

                                                barmar