Issue: HASH-TABLE-PACKAGE-GENERATORS (version 4)

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

I approve the WITH-HASH-TABLE-ITERATOR portion of
HASH-TABLE-PACKAGE-GENERATORS:ADD-WITH-WRAPPER.

I have two problems with WITH-PACKAGE-ITERATOR.  First, you use the
undefined phrase "available in the indicated package" a few times.  I
think you mean "accessible in the indicated package" (defined on CLtL
p.172).  The more important problem is that I think the syntactic
problem noted in the discussion section makes WITH-PACKAGE-ITERATOR
unacceptable.  I don't like having a required argument that is ignored,
and I don't like having those two unspecified cases: either the meaning
should be specified or they should signal an error.

I have two suggested alternatives that I think solve this.  Either of
them would be acceptable to me.  The second is simpler than the first so
I mildly prefer it.  If you like I can edit up an alternative proposal,
but I thought I would start by just presenting alternatives to this one
small piece of your proposal.

Alternative syntax #1:  In place of

	WITH-PACKAGE-ITERATOR ((<next-fn> <package>                         [Macro]
				&key external internal inherited)
			       &body body)

let's use the syntax

	WITH-PACKAGE-ITERATOR ((<next-fn>                                   [Macro]
				&optional <package>
				&rest symbol-types)
			       &body body)

The symbol-types arguments are symbols from the set {:INTERNAL, :EXTERNAL,
:INHERITED}.  Their order does not matter.

(WITH-PACKAGE-ITERATOR (next) body) is DO-ALL-SYMBOLS.
(WITH-PACKAGE-ITERATOR (next pkg) body) signals an error for invalid syntax.
(WITH-PACKAGE-ITERATOR (next pkg :EXTERNAL) body) is DO-EXTERNAL-SYMBOLS
(WITH-PACKAGE-ITERATOR (next pkg :INTERNAL :EXTERNAL :INHERITED) body) is DO-SYMBOLS
etc. for the other five cases.

Alternative syntax #2: Use the syntax

	WITH-PACKAGE-ITERATOR ((<next-fn>                                   [Macro]
				&optional <package>)
			       &body body)

If <package> is supplied, this is DO-SYMBOLS, otherwise it is DO-ALL-SYMBOLS.
The third value returned by <next-fn> can be used to filter out unwanted symbols
when doing such operations as DO-EXTERNAL-SYMBOLS.