From: Steve Watkins 
Here's an issue for those of you who have a little spare time to think =
this thru.  If you don't have the time, don't worry with it.
In the current TSE macro language we have a 'var' modifier.  This is =
used to specify that a variable passed as a parameter to a procedure can =
be modified by that procedure.
But one of the problems is this: (Consider the following macro)
    proc InitVars( VAR string s )
        s =3D "Hello"
    end
    proc Main()
        string msg[10]
        InitVars(msg)
    end
When 'msg' is passed to InitVars() an error message is given that 'msg' =
is possibly used before initialization.  But the intent of InitVars() =
here is to initialize the variable.
One of the little additions in the next SC is the addition of a 'varout' =
modifier.  This is used when a procedure will DEFINE the variable before =
returning but does not need the variable to be initialized when it's =
passed to the procedure.
Allowing
    proc InitVars( VAROUT string s )
        s =3D "Hello"
    end
does not require that 'msg' is initialized when passed to InitVars(). =
Moreover, 'msg' is then considered DEFINED after the call to InitVars() =
(possibly avoiding additional warnings and errors).
But here's the issue:
    'VAROUT' does not require the variable passed to already be defined, =
and it considered DEFINED once passed to the procedure.
    But 'VAR' _does_ require the variable to be initialized before it is =
passed and the returned value is not considered DEFINED by the function.
So: What I'm considering is making 'VAR' mark the passed variable as =
DEFINED.  Thus the 'VAR' parameter would still require the variable to =
be initialized before it is passed but henceforth is considered DEFINED.
Aside: The difference in my terms INITIALIZED and DEFINED is that any =
global variable is INITIALIZED by SC to a known value.  But it is not =
considered DEFINED until that variable is assigned a value by the user. =
This is one way of fleshing out unused variables.
Here's the change in tabular form:
                    Variable must be            Variable is DEFINED
                    Initialized before          upon exiting procedure.
                    passing
Currently:
 (not supported)    No                          No
 (not supported)    No                          Yes
VAR                 Yes                         No
 (not supported)    Yes                         Yes
Proposed:
 (not supported)    No                          No
VAROUT              No                          Yes
 (not supported)    Yes                         No
VAR                 Yes                         Yes
So, the main question is:
Are there any real-world problems changing the 'VAR' modifier to mark =
the passed variable as DEFINED?  (I can come with some but they are more =
contrived than real)
Steve
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