GSOC | Extending Common Lisp support

[Jamison Hope]

On Jun 7, 2012, at 1:20 PM, Charles Turner wrote:

> On 7 June 2012 17:20, Jamison Hope <jrh@theptrgroup.com> wrote:
>> Anyway, I don't expect syntax-case to get much use from Common Lisp
>> (though I see no reason why that should be prohibited), so let's not
>> spend too much time on that right now.
>
> I was only working on it because Helmut has done a lot of work making
> that LOOP implementation in Scheme.

Understood. Just had to put my GSOC Mentor Gotta Keep Student Focused
hat on for a minute. :-)

> Had I implemented LOOP in CL, I
> would have wanted it to be usable from Scheme also (it's a kick-ass
> macro :-D), so I see no reason why the reverse shouldn't be true,
> maybe Per can throw his disassembler at the syntax-case problem as
> well :-)

Perhaps!

>> Note the special (i.e. dynamic variable) *PACKAGE*:
>> http://www.lispworks.com/documentation/lw50/CLHS/Body/v_pkg.htm
>> which needs to be consulted when looking up symbols. I'm not entirely
>> sure how that should change the existing Environment searching.
>
> What would need to change? Would you not just perform a
> LispPackage#lookup in the current package (Namespace), which will
> first search the symbols exported in *PACKAGE*, and then it will
> search the inheritance (perhaps that word is bit strong for whats
> going on here...) chain created by DEFPACKAGE?

Sounds right, but nothing uses LispPackage yet AFAICT. I guess what I
meant isn't that the Environment search itself needs modification, just
that we need to make sure that the Environment ends up seeing the
right Symbol. CLTL2 says on page 14 "The parser recognizes symbols by
looking up character sequences in the current package." But I think
right now there are a number of places (e.g. in LispReader) which assume
the empty namespace is the package (look at ReadTable#makeSymbol).

>> Chapter 21 of Practical Common Lisp might help:
>> http://www.gigamonkeys.com/book/programming-in-the-large-packages-and-symbols.html
>
> Thanks!
>
>> Per probably Just Knew, but I looked at the output of
>> --debug-print-final-expr,
>> [...]
>
> I appreciate the battle stories, I've learned several new tricks which
> hopefully I can apply to the next bug :-)

:-)

> I'm working on packages now, I've added nickname support in
> LispPackage, and now I'm starting to write interpreter entries to the
> functions already open-coded from the compiler.

Awesome!

> Regards,
> Charles.

--
Jamison Hope
The PTR Group
www.theptrgroup.com