From: Andy
Subject: Newbie question: Variable with package scope ?
Date: Thu, 16 May 2002 14:14:28 +0000
Message-ID: <3CE3BEC4.AFAF3BB9@smi.de>

Hi all,
i wonder if it is possible to create a variable with the
scope of a package that can hold global values that are
used in the package but is not available outside the package
(and so doesn't produce nameconflicts outside the package).

Best
AHz

• Re: Newbie question: Variable with package scope ? Marco Antoniotti
• Re: Newbie question: Variable with package scope ? Joe Marshall
  • Re: Newbie question: Variable with package scope ? Andy

From: Marco Antoniotti
Subject: Re: Newbie question: Variable with package scope ?
Date: Thu, 16 May 2002 15:02:40 +0000
Message-ID: <y6cu1p8p23z.fsf@octagon.mrl.nyu.edu>

Andy <···@smi.de> writes:

> Hi all,
> i wonder if it is possible to create a variable with the
> scope of a package that can hold global values that are
> used in the package but is not available outside the package
> (and so doesn't produce nameconflicts outside the package).
> 

In in file my-pkg.lisp

        (defpackage "MY-PACKAGE"
            (:export "ONE" "TWO" "THREE"))

In file zut.lisp

        (in-package "MY-PACKAGE")

        (defvar *my-global-var* 42)

In file zot.lisp

        (in-package "ANOTHER-PACKAGE")

        (use-package "MY-PACKAGE")

        (defvar *my-global-var* 666)

At this point you have no conflicts and the two variables hold
different values.

Cheers

-- 
Marco Antoniotti ========================================================
NYU Courant Bioinformatics Group        tel. +1 - 212 - 998 3488
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From: Joe Marshall
Subject: Re: Newbie question: Variable with package scope ?
Date: Fri, 17 May 2002 01:38:21 +0000
Message-ID: <haZE8.6133$Bn5.2632540@typhoon.ne.ipsvc.net>

"Andy" <···@smi.de> wrote in message ······················@smi.de...
> Hi all,
> i wonder if it is possible to create a variable with the
> scope of a package that can hold global values that are
> used in the package but is not available outside the package
> (and so doesn't produce nameconflicts outside the package).

Packages are mappings from strings to symbols, so the
expression `variable with the scope of a package' doesn't make
sense to me.

Nameconflicts only arise when you import or export symbols
or change which packages are `used' by other packages.
Assigning a value to a variable is not one of these.

From: Andy
Subject: Re: Newbie question: Variable with package scope ?
Date: Fri, 17 May 2002 11:00:16 +0000
Message-ID: <3CE4E2C0.70282B72@smi.de>

Joe Marshall wrote:
> 
> Nameconflicts only arise when you import or export symbols
> or change which packages are `used' by other packages.
> Assigning a value to a variable is not one of these.
So, since variables are even symbols they need to be exported from
the package. OK, i thought that only holds for functions.
Thanks for the advice.
Best regards
AHz