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It will only read the file once.. Is that what you meant to do? Bradley V. Stone bvstone@taylorcorp.com http://prairie.lakes.com/~bvstone/ "She's into Malacas, Dino." > -----Original Message----- > From: Jeff Gunter [SMTP:JeffGunter@as400guy.com] > Sent: Monday, May 11, 1998 7:22 PM > To: MIDRANGE-L@midrange.com > Subject: Re: what is unclear - LEAVE > > I don't want to beat this to death, but Simon's last example could be > further simplified (I know... so what?) and I think be just as clear > as follows: > > C DO > C READ FORMAT 90 > C 90 LEAVE > C <<DO STUFF>> > C ENDDO > > Believe me, I don't want to restir the conditioning indicator pot > again, but in this case, I think it is pretty clear its purpose. > Control of the section of code is clearly associated with the activity > (READ). This isn't pure structured code, but it reads well. > > -- > Jeff Gunter > IBM Certified Specialist - AS/400 RPG Programmer > _______________________________________ > Visit my Web Site at: > > <http://www.as400guy.com/> > > > > Simon Coulter wrote: > > Hello Paul, > > The priming read isn't sloppy; it's a standard design pattern. > It avoids the extra IF test (inside the loop) to > cope with EOF which means half as many tests in your loop > construct. For example: > > C *IN90 DOUEQ *ON > C READ FORMAT > 90 > C *IN90 IFEQ *OFF > * do stuff > C ENDIF > C ENDDO > > Of course many of the list members would code that as: > > C *IN90 DOUEQ *ON > C READ FORMAT > 90 > C 90 LEAVE > * do stuff > C ENDDO > > But you still get the unnecessary extra test. > > I used to code this way until I measured the cost of the extra > tests over millions of records. Changing to the > the priming read and a DOW saved many minutes in a job where > those saved minutes counted. Now it's habit. > > Regards, > Simon Coulter. > > //---------------------------------------------------------- > // FlyByNight Software AS/400 Technical Specialists > // Phone: +61 3 9419 0175 Mobile: +61 3 0411 091 400 > // Fax: +61 3 9419 0175 E-mail: shc@flybynight.com.au > // > // Windoze should not be open at Warp speed. > > > //--- forwarded letter > ------------------------------------------------------- > > Date: Thu, 07 May 98 21:51:11 -0400 > > From: "PaulMmn" <PaulMmn@ix.netcom.com> > > To: MIDRANGE-L@midrange.com > > Reply-To: MIDRANGE-L@midrange.com > > Subject: Re: what is unclear - LEAVE > > > > > >(BTW, my preference is a DOW with a priming read, and a read > at the bottom > > >of the loop) > > > > > >Regards, > > > > > >Rick > > > > > > It's always struck me as sloppy coding to require 2 reads for > the same > > file... (: I'm not really sure of what logic I like to > eliminate this > > 'priming read,' but I know I don't like that extra read. > > > > > > --Paul E Musselman > > PaulMMn@ix.netcom.com > > +--- > | This is the Midrange System Mailing List! > | To submit a new message, send your mail to > MIDRANGE-L@midrange.com. > | To unsubscribe from this list send email to > MIDRANGE-L-UNSUB@midrange.com. > | Questions should be directed to the list owner/operator: > david@midrange.com > +--- > > > > +--- | This is the Midrange System Mailing List! | To submit a new message, send your mail to MIDRANGE-L@midrange.com. | To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: david@midrange.com +---
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