Dot notation and a crazy idea

Andrzej Turowski andrzej at turowski.com
Mon Mar 22 20:07:02 UTC 1999


How about the use of double dot or double colon

object..name 

object::name

-----Original Message-----
From: Doug Way <dway at mat.net>
To: squeak at cs.uiuc.edu <squeak at cs.uiuc.edu>
Date: 22 March 1999 07:32
Subject: Re: Dot notation and a crazy idea


>
>On Fri, 19 Mar 1999, Marcel Weiher wrote:
>
>> I also am reminded of C-- etc. when I see all those dots, so are
>> there ideas for another equivalent path-separator or do we just have
>> to overcome our collective phobia?  (Spaces don't cut it because
>> then you don't have the close binding of the path expression.  Well,
>> at least my eyes have difficulties picking it out).
>
>While I think that Travis Grigg's description of the various Smalltalk
>symbols on his webpage was excellent, I think it can be argued that the
>dot "." (period) separator is actually slightly better for namespaces than
>a slash "/" symbol, for a few reasons:
>
>- The dot is vaguely familiar as a separator for several different
>reasons, whereas the slash separator in a series is really only familiar
>for one reason, as a pathname separator.  I think this might tend to
>mislead people into thinking that these slashed namespaces were actual
>file pathnames (although I suppose they would get over it).  Dot are used
>as separators for a variety of different things, not just in C/Java, but
>also they're familiar from filename extensions (Squeak2.3.image), internet
>domain name addresses (www.squeak.org), etc.  So I don't think there would
>be an immediate confusion with any particular convention outside of
>Squeak.
>
>- The dot seems like a less "severe" separator than the slash, and thus
>names including dots read better as a single entity... probably simply
>because dots are smaller.  The filename extension comparison works here
>too... Squeak2.3.image still feels like a single name, whereas
>Squeak2/3/image is more broken up into parts. (Or could it be argued that
>being broken up is better?)
>
>It's true that the dot is already used for two other purposes in
>Smalltalk, as a statement ender and as a decimal point... definitely a
>reason for caution.  But these two other uses are unrelated enough so that
>at least there wouldn't be confusion between a namespace separator dot and
>a statement ending dot when looking at actual code.  You get into real
>trouble (with C++ etc.) when a symbol has a few related but still
>different meanings.
>
>> However, the '.' was proposed for another purpose, namespace
>> support.  My idea was that once you have it, why not make it general
>> and use it to simplify another part of the syntax that can get really
>> ugly really quickly?
>
>Not a bad idea... any syntax change in Smalltalk needs to "carry its
>weight", so it might as well be as general as possible.  Probably an idea
>to keep on the back burner for awhile (blue plane) before replacing all of
>the calls to select:/collect: in the Squeak image, though. :-)
>
>I've also always thought that the @ sign was underutilized in Smalltalk...
>changing at: to a binary @ would be great also for the higher precedence
>of a binary operator.  Although replacing at:put: is more of a
>challenge... I wouldn't go so far as adding new syntax (such as the
>suggested a[1] := b[3] etc.).
>
>- Doug Way
>  EAI/Transom Technogies, Ann Arbor, MI
>  dway at eai.com, dway at mat.net
>  http://www.transom.com
>
>  Smalltalk: Guaranteed Y2T Compliant
>
>





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