Newsgroups: comp.lang.apl
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From: dje@sspiff.ampr.ab.ca (Doug Evans)
Subject: Re: APL acceptance
Organization: Edmonton, Alberta
Date: Fri, 15 May 1992 22:21:16 GMT
Message-ID: <1992May15.222116.2936@sspiff.ampr.ab.ca>
References: <920514060533_70530.1226_CHC34-1@CompuServe.COM>

>Oh, I forgot to mention that if you don't like the name of an "exposed"
>item in a packaged WS (because, for instance, it conflicts with a name 
>already in use in the name scope where you want to use facilities from
>the packaged WS), you can supply an alias by which the item is to be known
>in the scope you are importing it into.  If I recall correctly you can
>even do this with system functions and system variables.  Yet another
>example of how thoroughly and intelligently thought out the implementation
>of this facility is.
>
>> Sharp APL has packages ... merely another implementation of )GROUP ...
>
>I should have mentioned this, but I was thinking of what APL2 offers. 
>BTW, Sharp APL packages are *not* just )GROUP with a different name,
>they are first-class entities:  assignable, producible as an explicit
>result, etc.  You can also get at values (of variables within a package)
>without establishing the original name in you ws via an expression such as
>
>      MINE <-- 'YOURS' []PVAL PACKAGE
>
>so they provide _some_ name scope isolation, at least for variables. 

Packages also let you page objects (fns and vars) in and out of the ws
while the application is running. Kind of useful.

There were various proposals at Sharp for extending packages to be
sort of like mini-wss (Hi Leigh!). I'm probably phrasing this badly ...
this is how I interpreted some of the proposals.
One could directly invoke functions in a package, and they provided a lot more
namespace isolation.
-- 
Doug Evans               | "You're just supposed to sit here?"
dje@sspiff.ampr.ab.ca    |               - Worf in a mud bath.
