You know, I've seen a lot of people get really steamed that there was a
RETURN in the middle of a well structured subroutine. Mostly because these
people SCREWED UP when they put something at the bottom of the subroutine
without checking, or worse TESTING the product before shoving it blindly
into production.
I see nothing wrong with a RETURN - especially in a validation subroutine.
Now.....an update subroutine is perhaps a bit different. If that needs to
be broken up, I usually do it at the CALLING level, i.e.:
BEGIN CASE
CASE LEVEL1
GOSUB LEVEL1.UPDATES
CASE LEVEL2
GOSUB LEVEL2.UPDATES
CASE REPRINT
GOSUB BUMP.REPRINT.COUNTER
END CASE
Here's something I thought about while looking at the possibility of not
putting in a RETURN while at the same time keeping the code structured
without a bunch of indented tabs:
B00.PROCESS:
BAD.HAPPENED = 1
LOOP
READ REC1 FROM file1,id1
ELSE EXIT
END
READ REC2 FROM file2,id2
ELSE EXIT
END
IF some.condition
THEN EXIT
END
BAD.HAPPENED = 0
EXIT
REPEAT
IF NOT(BAD.HAPPENED) THEN
some more statements
that actually do the work with REC1 & REC2
END
RETURN
This does make it apparent that the subroutine is not being abandoned, while
making a unique use of the LOOP/REPEAT/EXIT construct, in that it is not
really a loop, but a method used for 'bouncing out'. It begins by assuming
BAD.HAPPENED and will only negate this if it reaches the bottom of the
decision stack.
I've never used this before, and doubt that I will, but it was an
intellectual exercise aimed at 'staying structured' with a minimum of
IF/THEN's. Personally, I just use the RETURN....no sense being 'analyst'
about it...... ;)
Allen
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Womack, Adrian
Sent: Tuesday, September 27, 2005 18:06
To: [email protected]
Subject: RE: [U2] Good Programming Practice Question.........
We also use "xnn.meaningful.name" type labels. One advantage is that our
editor can recognise a label and putting the cursor on a line that
includes a GOSUB and pressing one function key will move the cursor
directly to the correct paragraph.
One thing I've never agreed with (except in COBOL) is "every internal
subroutine should only have on exit point" - why?
What is wrong with...
B00.PROCESS:
READ REC1 FROM file1,id1
ELSE RETURN
READ REC2 FROM file2,id2
ELSE RETURN
IF some.condition
THEN RETURN
some more statements
that actually do the work with REC1 & REC2
RETURN
The early RETURNs are just getting out of the routine on abnormal
conditions, the alternative would be to nest the code - but code nested
more than a couple of tabs deep is *much* harder to read.
AdrianW
DISCLAIMER:
Disclaimer. This e-mail is private and confidential. If you are not the
intended recipient, please advise us by return e-mail immediately, and
delete the e-mail and any attachments without using or disclosing the
contents in any way. The views expressed in this e-mail are those of the
author, and do not represent those of this company unless this is clearly
indicated. You should scan this e-mail and any attachments for viruses. This
company accepts no liability for any direct or indirect damage or loss
resulting from the use of any attachments to this e-mail.
-------
u2-users mailing list
[email protected]
To unsubscribe please visit http://listserver.u2ug.org/
-------
u2-users mailing list
[email protected]
To unsubscribe please visit http://listserver.u2ug.org/
