RE: Multi- Occurrence Data Structure

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...
--
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