[Oberon] Tidyness of iteration.

[Jörg]

LOOP: R.I.P

 

Even the main Oberon loop (you know, the one that never ends :-) is
programmed with

REPEAT




UNTIL FALSE

 

Jörg

 

From: Oberon [mailto:oberon-bounces at lists.inf.ethz.ch] On Behalf Of Bob
Walkden
Sent: Montag, 14. November 2016 20:35
To: ETH Oberon and related systems <oberon at lists.inf.ethz.ch>
Subject: Re: [Oberon] Tidyness of iteration.

 

(One must wonder about discarding REPEAT and WHILE and retaining LOOP with



strictly one EXIT.)

 

Er, definitely not. The read-ahead technique is very valuable in structuring
the software to match the structure of the input stream. It's a key
technique in Jackson Structured Programming, for example. It makes code a
lot easier both to write and, perhaps more importantly, to read and
understand. I can't tell you the number of programs over the years that I've
had to deal with where the programmer didn't understand this and
consequently ended up with a buggy, difficult-to-maintain mess.

 

The programming language RPGIII, at least when I used it in the 90s, had by
default an automatic outer loop structure and you determined your position
in the structure by means of bit-flags. It led to some really messy code,
which although quick to write (partly because of in-built DB2) was difficult
to support. Especially at 3:30 on a Sunday morning over a telephone dial-up.

 

If any of those are to be discarded, let it be LOOP, which encourages
badly-structured code.

 

B 

 

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