[PD] difference send and using msg with ";"

Matteo Sisti Sette matteo.sistisette at email.it
Tue Aug 21 12:27:02 CEST 2007

Excerpt from a PD class in 2010 (when $0 for message boxes has been 
implemented meaning the same as a $0 in an object box):

STUDENT: So a $ sign in an object means a creation argument of the 
abstraction instance. But I've seen some $0's around... I thought $1 was the 
first creation argument.
TEACHER: Yes, $1 is the first creation argument. $0 is a sort of special 
implicit creation argument which is a number assigned by PD unique to a 
patch. It is especially useful as a prefix for assigning "local" names to 
sends, receives, values, etc.
STUDENT: Oh, I see. Now, I have tried using $1 and $2 in this message box, 
but I get confusing and unexpected results.
TEACHER: (looks at the student's patch) That's because a dollar sign in a 
message box is not the same as a dollar sign in an object box. In a message 
box, $1 and $2 are the first and second argument of the message that is 
input to the message box. They may change every time a message is received.
STUDENT: (showing another patch) Oh. So what does the $0 mean in this 
message box?
TEACHER: Well, $0 in a message box *is* the same as in an object box. So you 
can access the $0 of the patch from within a message without making a clump 
around the message box.
STUDENT: And what if I need to access the $1 or $2 of the patch from within 
a message?
TEACHER: You have to make a clump around the message box. 

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