Global namespace (was Re: python libs v lisp coolness?

[Christophe Rhodes]

Ville Vainio <ville.spammehardvainio at spamtut.fi> writes:

> Paolo Amoroso <amoroso at mclink.it> writes:
>
>> The lack of Lisp libraries is being addressed.
>
> Are they also going to address the lack of modules? The way I've seen
> Lisp used, everything is dumped into a global namespace (even
> "methods" in CLOS). I shudder at the thought of using Python where all
> the names from various modules would be in the global namespace.
>
> in Python you can do:
>
> import os
>
> files = os.listdir("/root")

Knowing no python, I believe the Common Lisp equivalent of this is
  (cl:defpackage "MY-APP" (:use "CL"))
  (cl:in-package "MY-APP")

  (os:listdir "/root")

Optionally, if one wishes to import an interface wholesale and use it
without qualification, one may USE-PACKAGE a package, for example:
  (cl:defpackage ("MY-OTHER-APP") (:use "CL" "OS"))
  (cl:in-package "MY-OTHER-APP")

  (listdir "/root")

[ this is written for maximum paranoia; usually you wouldn't see the
  cl: prefixes on defpackage and in-package. ]

Ancient code is typically less careful about stomping over the global
namespace; if you see (in-package "CL-USER") anywhere, reeducate the
maintainer of the code :-)

Christophe
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