Re: Max length of a VARYING field

["Peter Dow (ML)" <maillist@xxxxxxxxxxxxxxx>]

Hi Joe,

I agree with this scenario, with a couple of questions.

Why VARYING(x) as opposed to VARYINGx?  The former implies (to me 
anyway) that I can put whatever I want in there -- VARYING(1), 
VARYING(7), etc.  Or maybe that's the intention; after all, why not?  
Let's be flexible.  Aren't all these 2-byte, 4-byte integers simply 
those sizes because they're closer to what the hardware can handle?  But 
isn't RPG supposed to be a little more hardware independent than that?  
After all, I don't have to know the size of a disk sector in order to 
read a record from a file.

Later responses mention a %indexsize BIF.  Index?  It's a current length 
subfield isn't it?.  How about %sizelen, or %lensize or something?  
Unless it's considered an index to the end of the string...but I think 
most people think of it as the current length, hence the %len BIF.

*Peter Dow* /
Dow Software Services, Inc.
909 793-9050
pdow@xxxxxxxxxxxxxxx <mailto:pdow@xxxxxxxxxxxxxxx> /

Joe Pluta wrote:
> The discussion has eovled primarily around syntax.  The consensus between
> Scott and Barbara seems to be that something like VARYING(2) for normal
> fields and VARYING(4) for longer indices or for special conditions would be
> the best solution, for a number of reasons they've already given.  Thus, you
> get the following:
>
>      D  mySmallVar     s            256A   VARYING(2)
>
> This is the standard.
>
>      D  mySmallVar     s            256A   VARYING(4)
>
> This says 256 byte field, but with a 4-byte prefix.
>
>      D  myBigVar       s         100000A   VARYING(4)
>
> This is a 100,000 byte field, prefix 4.
>
>      D  myBigVar       s         100000A   VARYING(2)
>
> And this, I assume, is a syntax error.
>
> In order to make it so that new programmers who don't care about prefix
> sizes don't ever need to even know about it, and additionally to allow
> backwards compatibility to all existing code, I would respectfully ask that
> the following be considered.
>
>      D  mySmallVar     s            256A   VARYING
>
>      D  myBigVar       s         100000A   VARYING
>
> In these cases, mySmallVar would default to VARYING(2) and myBigVar would
> default to VARYING(4) without any additional code required.  For someone who
> isn't interested in internals, the keyword would be consistent and nobody
> would care.  Those requiring compatibility with APIs and such could always
> override the VARYING keyword as needed.
>
> This seems to me to be the most flexible compromise: easiest for the new
> programmer yet ultimately flexible for the experts.
>
> Joe
>
>
>