RE: Scope of variables and subprocedures.

[Colin Williams <Williamsc@xxxxxxxxxxxxxxxxx>]

Barbara,  what other things that you think RPG needs, out of interest?

>-----Original Message-----
>From: bmorris@ca.ibm.com [mailto:bmorris@ca.ibm.com]
>Sent: Monday, December 13, 1999 3:59 PM
>To: RPG400-L@midrange.com
>Subject: Scope of variables and subprocedures.
>
>
>
>
>
>>Date: Sat, 11 Dec 1999 20:56:26 -0700
>>From: Alan Campin <Alan.Campin@CaseLogic.com>
>>
>>The problem concerns the scope of variables. In language like "C" or
>"Java"
>>or "Pascal", I can do the following:
>> ... example of nested subprocedures
>> ...
>> To get around this, I have three choices that I can see.
>>
>> 1. Pass every variable needed by anyone of the procedures to each
>> procedure.
>> ...
>> 2. Make any variable needed by different subprocedures global.
>> ...
>> 3. Use subroutines.
>> ...
>
>Alan, you are right that you can do this in Pascal, but 
>neither C nor Java
>supports nested procedures.  It's true that you can sort of do 
>this in Java
>with nested classes. C and Java do allow you to have variables 
>scoped to a
>block within a procedure, but the block isn't callable from within the
>procedure.
>
>I realize that C's deficiency doesn't mean RPG isn't 
>deficient.  I agree
>that nested subprocedures would be nice to have, but I can't 
>say that it
>will happen in my "lifetime" since there are other things that 
>RPG needs
>that are more important (in my opinion anyway).
>
>One solution that you haven't mentioned is moving the procedure that
>requires nested subprocedures into another module, and making those
>variables global within that module, but not visible outside 
>the module.
>(Of course, this solution only works if the procedures don't need other
>global variables.)
>
>Barbara Morris, IBM Toronto Lab, RPG Compiler Development
>
>
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