× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.




Dave wrote:

But ITER and LEAVE are really GOTO in a cage. They are extremely
useful for practical programming but they are in a sense dirty tools
that violate the idea of a single exit and entry point.

RPG is really just MI in a cage and MI is just bits and bytes in a cage. One of the most important (and neglected) aspects of programming is making the right abstractions. ITER and LEAVE are abstractions of a GOTO, yes, like IF and DOW are "caged" combinations of COMP and GOTO, but these "caged" GOTO's are unambiguously defined, .i.e. you always GO TO the end of the block, not to a random point in code, e.g. somewhere outside of the block. And thus, there *is* a single exit point.

Jacobus



Date: Fri, 14 Dec 2007 11:43:58 +0000
From: dkahn400@xxxxxxxxxxxxxx
To: rpg400-l@xxxxxxxxxxxx
Subject: Re: Multi- Occurrence Data Structure

On 12/12/2007, James Lampert <jamesl@xxxxxxxxxxxxxxxxx> wrote:

Maybe GOTO, given that there are more elegant ways to, for example,
leave a loop prematurely (something that was left out of that paragon of
structure, Pascal, because Wirth somehow couldn't imagine situations in
which a premature exit was normal, but completion indicated an error --
like he'd never done a table-lookup?).

But ITER and LEAVE are really GOTO in a cage. They are extremely
useful for practical programming but they are in a sense dirty tools
that violate the idea of a single exit and entry point.

--
Dave...
--
This is the RPG programming on the AS400 / iSeries (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.


_________________________________________________________________
Jouw nieuws en entertainment, vind je op MSN.nl!
http://nl.msn.com/

As an Amazon Associate we earn from qualifying purchases.

This thread ...

Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.