Show globals

Rob Cozens rcozens at pon.net
Thu Dec 11 13:56:00 EST 2008


Bob, et al:

>I would only use
>script local variables for temporary variables that only need to live
>while the script runs

The Rev Dictionary says:

"The difference between a script local variable and a global variable 
is that a script local variable can only be used in the handlers of 
one script, while a global variable can be used in any handler or 
script with a global declaration for that variable.
.
[snip]

The value of a script local variable is retained between handlers, 
but is lost when you quit the application, when you close the stack 
(unless its destroyStack property is false), or when the script is 
re-compiled."

So script local variables have value persistence so long as the stack 
or app remains open.

And script local variables cannot be accidentally or purposely read 
or changed by scripts in other stacks or other objects.

Having said the latter, I would note that any script local variable 
can be accessed by handlers in other scripts or stacks, if the script 
declaring the local variable includes a getValue function and a 
setValue command for that variable.  Eg:

local mySharedVariable

function getValue
    return mySharedVariable
end getValue

on setValue newValue
    put newValue into mySharedVariable
end setValue


Rob Cozens, CCW
Serendipity Software Company

Vive R Revolution! 


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