[PD-dev] $0 in messages, was: multiple $arg-expansion

[Hans-Christoph Steiner]

On Jan 15, 2006, at 4:01 AM, IOhannes m zmoelnig wrote:

> Thomas Grill wrote:
>>
>>> do you mean, is there a reason for my patch, a reason for $0 or a  
>>> reason for $0 being "different" in messages?
>> the latter (your patch is great, although i'd like to have even more
>
> well i think this is very consistent: $args in messages refer _only_  
> to parameters of incoming messages, while $args in objects refer only  
> to parameters of upstream objects. (and $0 is bound to the class  
> instance)
>
> however, i think that "$0" is a bad name.
> i would have liked it better if $0 was the selector (in messages) and  
> the classname (in abstractions).
> probably "$$" would have been better for a uniq id (well, i know that  
> this is a bashism (its the process-id in bash), but that is not  
> necessarily bad)

This sounds logical.  I have a question about the selector tho.  So if  
I send [1 2 3(, would the $0 selector be "list" or would it be "1"?

As for implementing this, we could add $$ as the instance ID, and $0 in  
messages as the selector.  Then have $0 default to classname in  
objects, but have a startup flag that reverted $0 to the old behavior  
for running old patches.  Why we are at it, $# for number of arguments  
and $@ for all arguments would be nice too.

>> flexible $args-processing).
>
> this is on my todo-list.
> 1st thing todo (soon!) is to remove the restriction that dollsyms have  
> to start with $

Yes, this would be good.

>  (while this restriction makes parsing trivial it is cumbersome at the  
> best)
> 2nd thing todo (LATER!) is a mechanism for stacked $args, like ${$1-2}

Stacked args would complicate things more than its worth.  I think it  
is getting away from the graphical nature of Pd programming and I can't  
think of any parallel structure in any language that uses $ variables.   
Couldn't you just use stacked messages with regular $ args?  That would  
be much more Pd-ish.

.hc

>> Sorry for continuing in your thread.
>
> better in this thread than never...
>
>
> mfmgasdr
> IOhannes
>
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