[PD] how to use a dollar argument

[Frank Barknecht]

Hallo,
ronny vanden bempt hat gesagt: // ronny vanden bempt wrote:

> In several patches I had the following problem:
> I make a patch that I'm going to use in another patch. To make it possible
> to use several of these subpatches in the main patch, I add a dollarsign
> where needed.
> But when I apply this to arrays, I cannot make it work.
> For example a block that applies a window. It's nothing more than a tabread
> block. But I have four files with a window in. So I call the array to read:
> $1-window. But when I want to read it with a message: $1-window read
> gaussBig.txt, it doesn't load. Probably this is because of the ambiguity
> between dollarsigns in a message and elsewhere, 

Exactly this is the reason. (Read on)

> or maybe due to the dollarsign not being replaced in the name of an
> array.

This is not the reason: Array names are just like any other name in
Pd, no exception.

But as you already wrote: dollar signs in messages and dollar signs in
object boxes are different. They are similar in that they both get
replaced by "something". But this "something" is different: message
boxes use, what they receive through their inlet, to do
$-replacements. You've probably already used this for example to
generate an "read file" message, for example for [textfile], when
using [openpanel]. It looks like this: 

 [bang(
 |
 [openpanel]
 |
 [read $1(
 |
 [textfile]

[openpanel] will send a message like "symbol /tmp/file.txt". The $1 in
"read $1" will take the first element of this message (counted
without the "symbol"-thing) and replace $1 with that so that you get a
"read /tmp/file.txt" message to [textfile].

In object boxes, $-variables however take the arguments that *a patch*
was created with to do the replacement. Patch arguments aren't bound
to messages. Even objects that don't have inlets for messages *at all*
can use argument dollar signs: an example would be [r $1-something].

Now what you need to do is convert a dollarsign as it is used in
object boxes to one, that is used in a message. That's actually very
simple: You first create an object with a dollarsign to get the
"object dollar", and then you connect this object to a  message box
with a "message dollar" inside. Example: 

 [bang(
 |
 [symbol $1]
 |
 [read $1(
 |
 [textfile]

The number - 1 in the example - can even be different, depending on
where your wanted argument is: 

 [bang(
 |
 [symbol $3]
 |
 [read $1(
 |
 [textfile]

That is possible, because object dollars and message dollars are
completely independent from each other.

Oh, and don't forget this: $0 is something else again and there is no
$0 in a message box.

Ciao
-- 
 Frank Barknecht                 _ ______footils.org_ __goto10.org__