RE: READE is confusing to me

["Shaw, David" <dshaw@xxxxxxxxxxx>]

Mark,

On the contrary, I think the BIFs are quite consistent.  The confusion is
the result of our long habit of using the same indicator number for
different functions in different op-codes.  It makes perfect sense to me
that a CHAIN would result in a %FOUND/NOT %FOUND and a READE would result in
a %EOF/NOT %EOF, and that these are different things.  However, after using
*IN90 for more than 10 years in both functions, it's disconcerting to have
to change one's thinking.  If we explicitly do what the indicators did
implicitly, though, I think the code actually becomes more understandable.
Consider a priming read loop done like this:

     D EndLoop         S               N


     C     Key           Chain(E)  File
     C                   Eval      EndLoop = Not %Found(File)

     C                   DoW         Not EndLoop

        *  stuff

     C     Key           ReadE(E)  File
     C                   Eval      EndLoop = %EOF(File)

     C                   EndDo

When I first tried to use the BIFs, it annoyed me that I couldn't just
substitute %EOF for *INxx, but it actually makes a whole lot more sense to
me to use something like EndLoop, mapped explicitly to the contextually
correct BIF.  What do you think?

Dave Shaw
Spartan International, Inc.
Spartanburg, SC

-----Original Message-----
From: M. Lazarus [mailto:mlazarus@ttec.com]

At 9/11/00 08:05 AM -0400, you wrote:
>%Equal is used on Setll or Lookup

  I think that the implementation of these BIFs makes them 
inconsistent.  Even though there was considerable thought behind it, I 
think it ended up being misguided.  I think that they s/b consistent for 
ALL I/O opcodes.  This means that all CHAIN's and READx's should have 
%Found and %EOF available.

  Does anyone else find the implementation confusing?

  -mark
+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---