[squeak-dev] Shadowing "reserved" variables

Marcel Taeumel marcel.taeumel at hpi.de
Fri Jul 19 05:40:28 UTC 2019

Shadowing those reserved variables seems to be a nice property that supports (crazy) language experiments. We shouldn't make use of it in Trunk, though.

+1 for adding a preference to raise a Warning (or Error) if somebody tries that
-1 for prohibiting that in Squeak's default parser all the time

Am 19.07.2019 04:15:28 schrieb Frank Shearar <frank.shearar at gmail.com>:
The snippet from the standard says that it is illegal to use these identifiers as method arguments. The example uses block arguments.

Now maybe a reasonable person would assume that argument names, regardless of whether method or block (especially if one views blocks as anonymous methods), come from the same set, and maybe it seems like a terrible idea to allow this kind of shadowing,  but I don't see the current behaviour as incompatible with the standard snippet.

So sure, forbid such shadowing because it's terrible, but I don't see it being ILLEGAL.


On Thu., Jul. 18, 2019, 18:26 JOHN SARKELA via Squeak-dev, <squeak-dev at lists.squeakfoundation.org [mailto:squeak-dev at lists.squeakfoundation.org]> wrote:

It is by definition erroneous. It is counter to the definition of the standard language. That is a problem that should be fixed.

On Jul 18, 2019, at 7:53 PM, Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com [mailto:nicolas.cellier.aka.nice at gmail.com]> wrote:

Is it really a problem?
Did the system horribly break?
IMO this should just be not recommended.

Le ven. 19 juil. 2019 à 00:39, Chris Muller <asqueaker at gmail.com [mailto:asqueaker at gmail.com]> a écrit :

Wow.  We should disallow that.  Those words are reserved.

On Wed, Jul 17, 2019 at 5:52 AM Levente Uzonyi <leves at caesar.elte.hu [mailto:leves at caesar.elte.hu]> wrote:

Hi All,

You can currently evaluate the following:

[ :self :thisContext |
        | nil super true false |
        nil := 1.
        super := 2.
        true := 3.
        false := 4.
        self + thisContext = (nil + super + true + false) ] value: 4 value: 6

Is this the expected behavior or should we disallow such oddities?


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