Re: C like Data Structure Definitions?

[Jim Langston <jimlangston@xxxxxxxxxxxxxxxx>]

Scott,

Hmmm... this gets rid of my problem about my data being public,
but... in this case don't I just have one copy of the data structure
out there?

As I understand your C method, to use this I would have to do something
like:

 *** In the copy source the data structure RNF_Data is set up based on 
RNF_Data@ ***
//COPY QMODSRC,SYSTEMPR                                              

D RNF_Data#       S            107A
                                                                     
C                   Eval      RNF_Data# = RNF_Open('QPGMR': 'ICS400') 
C                   Eval      RNF_Data@ = %addr(RNF_Data#)

C                   DoW       NOT RNF_Data = *Blanks

C                   If        NetFile = 'MYFILE'
                    ...
C                   Eval      RNF_Data# = RNF_Read
C                   Eval      RNF_Data@ = %addr(RNF_Data#)

C                   EndDo

The whole point being, I am going to have to reset the pointer to my local data 
buffer
every time I call a function that could set it to it's own local data buffer 
(like RNF_Open
and RNF_Read would do).

I like it, I just don't like the side effect of functions changing my pointer, 
which is
at this point a global variable.

Regards,

Jim Langston

Scott Klement wrote:
 
> C) Use pointer-based structures in a /COPY file, and then define a local
>           variable for each copy of the structure you want, and point
>           the DS at the local var.
> 
>           Like so:
> 
>           (in /COPY member:)
>           D mystruct      ds                    BASED(p_mystruct)
>              ... subfields here....
>           D p_mystruct    S               *
> 
>           (in proc where you use it:)
>           D/COPY SOURCE,MEMBER
>           D MyNewStruct   S             16A  (or however big the DS is)
>           D MyNewStruct2  S             16A  (or however big the DS is)
>           c                   eval      p_mystruct = %addr(mynewstruct)
>           c     ... work with vars in mynewstruct ...
>           c                   eval      p_mystruct = %addr(mynewstruct2)
>           c     ... work with vars in mynewstruct2 ...
> 
> Personally, I find myself using "C".  I like putting my structures in the
> same /COPY member as the prototypes that they correspond with.  Most
> people, however, aren't as comfortable with pointers as I am.
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