the := operator (affectation

[Jim MacConnell]

Hi.

I've been "listening" to this discussion and find it intriguing. I  
personally have nothing against ":=" and "=" for variable assignment  
and have used them when using a tool that requires them. I also can  
quickly adapt to the "==" concept for comparisons and "=+" for  
incrementing  (Though that one still hurts my brain a little). So...  
while the discussions about operators has been interesting, it is not  
something that stirred any passion.... Until the "gets" discussion  
that is.... and then I realized that I do care....

My problem with the concept of "gets" is that I can't see how it fits  
within the conceptual framework of xTalk where we (the coders) are  
telling an object (a button, a field, etc.) what to do when a certain  
message is received (on blah). The "put" and "get" constructs fall  
neatly into that vision as does (not surprisingly) most/all other  
elements (send, do,etc.). In a polite form of the "verbose", we are  
saying "Please, Button, when you receive a 'mouseUp' message do this  
and this and this also".  Often, we will throw in a customHandler  
"xxx" which the object figures is a message if we don't tell it  
otherwise and so we don't have to say "Send xxx to the target" all  
the time.

In contrast what is going on with the "gets" construct? Here some  
renegade variable is off filling itself with data and the button can  
only assume that it is being done... a weird sort of coding  
delegation which makes sense in a some environments but not xTalk. It  
is more like  "Please, Button, when you receive a 'mouseUp' message  
do this and this and Ooops.. this isn't meant for you so don't pay  
any attention (Variable... go stuff yourself with something).. and  
now where were we.. Oh yes.. and this and this...and I hope the  
variable did its thing because I know you didn't do it Button but I  
hope the data is there cuz now I need you to do this.... and this    
and this also".  I mean "Where's the message?".

I don't mean to be totally facetious but the concept of message path  
and message passing within the confines of a relatively limited set  
of "near physical" objects  is in what I view as the core concept of  
xTalk. The "affectation" discussion is really about alternatives for  
those who have learned to program in non-message based environments.  
(Or so my thoughts at this instant indicate)..... and this extends to  
those thinking ":=", etc. would be a good addition to Transcript.  In  
contrast I think adding the "put x into y" construct would help a lot  
of other code (C, VB, ++)  be more readable....

Getting back to "gets"... is it really that much harder to type "put  
(the x of y) into z" versus "z gets the x of y".

okay.. back into my hole...

Jim


James H. MacConnell

Consensus Technology, LLC
2200 N. 77th St.
seattle, WA  98103-4928
www.consensustech.com
Tel: 206.524.8555
Fax: 206.524.3034



On Jun 23, 2005, at 12:57 PM, Dennis Brown wrote:

>  I would be happy to be able to change "get x" to "myVariable gets   
> x".