Re: Adding another subfield to an externally defined data structu re.

["Michael Naughton" <mnaughton@xxxxxxxxxxxx>]

I just had a chance to check the archives, and back in September, 2002, I
found this from Barbara Morris:

" . . . even though the fields are contiguous in the file, they aren't
necessarily contiguous in the program storage. But you can force them to
be contiguous by coding an externally-described data structure. You just
need to add one line to your program:

 D E DS EXTNAME(myfile) "

and this from Jon Paris:

"You need to use the file to describe an externally described DS. It is
the only way you can guarantee that the fields will be contiguous in
memory."

These were in response to a question from Don Fisher, who was having
trouble defining an array over fields in a data file (the fields seemed
contiguous in the file, but the array was not being filled properly).

The weight of expertise behind these opinions is what makes me pretty sure
I'm right that my method works. And I don't have any gripe against LIKEREC
- I was just reading the discussion of it's advantages and array
definition piece caught my eye. . . .


RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx> writes:
>Anyone else feel like jumping in?
>
>Rob Berendt
>-- 
>"They that can give up essential liberty to obtain a little temporary 
>safety deserve neither liberty nor safety." 
>Benjamin Franklin 
>
>
>Hi Rob,
>
>Actually, I'm not chaining/reading into a data structure - my file is
>externally defined, and I'm chaining/reading into the record format.
>
>My question is: Since I have an externally-defined data struture using the
>same file, when I chain/read into the record format don't the fields end
>up also being "in" the data structure? And since they're "in" the data
>structure, aren't they contiguous?


Mike Naughton
Senior Programmer/Analyst
Judd Wire, Inc.
124 Turnpike Road
Turners Falls, MA  01376
413-863-4357 x444
mnaughton@xxxxxxxxxxxx