RE: Chain doesn't set %EOF

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

Hi Paul!

The thinking is that you didn't actually hit end of file.  Only a READ
can hit the end of file; CHAIN can only either find or not find a
record.  Yeah, it's a pain in the butt because it blows up the shortcut
that many of us have used for 20 years or so.

I understand the thinking that %EOF and %FOUND are different.  How about
a new BIF that does what we want?  Like %DATA.  If a CHAIN *or* a READ
are successful in putting data into the buffer, then %DATA is true.  We
could then do this:

Chain ( SomeKey ) File;
DoW %Data( File );
   // do something
   ReadE ( SomeKey ) File;
EndDo;

Joe


> From: Paul Morgan
> 
> Why doesn't a failed CHAIN (which sets off %FOUND) also set on %EOF?
> 
> Rather that doing a SetLL/ReadE combo to start the loop it used to be
> shorthand to code a Chain with:
> 
> Chain ( SomeKey ) File;
> DoW Not %Eof( File );
>    // do something
>    ReadE ( SomeKey ) File;
> EndDo;
> 
> except Chain doesn't fiddle with %EOF so this won't work.