RE: read on a do loop

On Fri, 2005-08-19 at 10:59 -0700, Joel Fritz wrote:
> Hmm...It's a religious question. I was brought up in the Brotherhood of
> the Priming Read.  At the risk of being branded a heretic for even
> considering the dread dou:
> 
> setll myfile;
> 
> dou %eof(myfile);
>     read(myfile);
> 
>     if NOT %eof(myfile);
>         do_stuff();
>     endif;
> 
> enddo;

The DOU-ers always seem to forget that there are two checks for eof and
an extra branch when using DOU.  Not a huge deal, but it does add
complexity to the code.

It occurs to me that if the read opcode would simply return 'true' or
'false' we wouldn't have to have these boring arguments about which loop
to use.  

I don't think it could be much simpler than:

/free
    dow read(myfile);
        // process the record
    enddo;
/end-free


Until such syntactic sugar is introduced into RPG to reduce our burden
of choosing an appropriate looping construct, I've devised the 'duzy
way' (tm) of file reading thusly:

     h dftactgrp(*no)
     h option(*srcstmt:*nodebugio)

     fexample   if   e           k disk

     d read_example    pr              n

      /free

         dow read_example();
             dsply ('got a record');
         enddo;

         *inlr = '1';

      /end-free


      *
      * read a record from the example file
      * return true if end of file is off
      * return false if a end of file is on
     p read_example    b

     d read_example    pi              n

     d result          s               n   inz('0')
      /free

         read example;
         if not %eof(example);
             result = '1';
         endif;

         return result;
      /end-free
     p                 e


A bit of extra code to combine the reading of the record with the
returning of the eof status, and Bob's your uncle.  

Perhaps one day the RPG gods will look kindly on us and introduce a 
'%read' bif that will return the EOF status.  It would be really great
if it could accept a variable that refers to any one of the compiled in
files as well.

YMMV.

Regards,
Rich