IF... (imperative) Not Necessarily So

Learn something new every day, it seems... and so I post it here to show
everyone how little I actually know.

(note - all compiler references are to IBM mainframe software)

I was taught the syntax of IF (condition) [THEN] (imperative statement).
.
and the compiler enforced this fairly well; even the venerable IKFCBL00
would throw a condition code of 12 on

IF FLD1 = ZEROES.

... and this holds for the IBM Enterprise COBOL for z/OS and OS/390 3.2.0
which I presently use at work; it returns

IGYPS2079-S   Expected a verb or "NEXT SENTENCE", but found ". ".

This syntax holds true for those who employ scope-delimiters, as well, as

IF FLD1 = ZEROES
END-IF

... with or without a period (full stop) following the END-IF generates

IGYPS2079-S   Expected a verb or "NEXT SENTENCE", but found "END-IF".

... as, some might argue, Well It Should Be.

However... I was given a chunk of code to modify, the scenario being that
they no longer wanted records with zeroes in a couple of fields.  At first
I was told that if the second field was zeroes the sign-indicator (a
separate alpha field preceding the numeric field... no SIGN LEADING
SEPARATE CHARACTER here!) should be blanked out since the indicator was
initialised to '+' in another section.  The output records were stored in
a WORKING STORAGE table and the code started out as:

PERFORM 9798-WRITE-DETREC THRU 9798-EX
VARYING SUB03 FROM 1 BY 1
UNTIL SUB03 > 14.
...

9798-WRITE-DETREC.
*
WRITE OUT-REC FROM WK-REC (SUB03).
ADD 1  TO  OUT-COUNT.
*
9798-EX.
EXIT.

So... I coded the following:

9798-WRITE-DETREC.
*
IF (WK-FLD1 (SUB03) = ZEROES)
IF (WK-FLD2 (SUB03) = ZEROES)
GO TO 9798-EX
END-IF
MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
END-IF.
*
WRITE OUT-REC FROM WK-REC (SUB03).
ADD 1  TO  OUT-COUNT.
*
9798-EX.
EXIT.

... and ran the job and submitted the test-results for examination.  I
then received the classic 'I know that's what we told you but it's not
what we want...'; seems that they wanted the second '+' back again because
it made it easier to eyeball the unformatted data... but I've been burned
by 'Take it out... put it back... now take it out again' before so I
changed a single character to make it:

9798-WRITE-DETREC.
*
IF (WK-FLD1 (SUB03) = ZEROES)
IF (WK-FLD2 (SUB03) = ZEROES)
GO TO 9798-EX
END-IF
*        MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
END-IF.
*
WRITE OUT-REC FROM WK-REC (SUB03).
ADD 1  TO  OUT-COUNT.
*
9798-EX.
EXIT.

Now... as I read the above the the GO TO is predicated upon a second-level
conditional... but there is *nothing* predicated on the first.

And yet... it compiles and runs and does just what I want.

DD

Your nested IF ... END-IF *is* an imperative statement (scope terminated
conditional statement) and as such THAT is  the "action" taken by your outer
most
IF.  This is just the same as:

IF A = "A"
Add 1 to X
On size error
Display "here"
End-Add
End-If

or (using another scope terminated conditional)

IF A = "A"
Evaluate X
When "Y"
Display "HERE"
End-Evaluate
End-IF

--
Bill Klein
wmklein <at> ix.netcom.com
<docdwarf@panix.com> wrote in message news:c27n36$h00$1@panix5.panix.com...
>
> Learn something new every day, it seems... and so I post it here to show
> everyone how little I actually know.
>
> (note - all compiler references are to IBM mainframe software)
>
> I was taught the syntax of IF (condition) [THEN] (imperative statement
)...
> and the compiler enforced this fairly well; even the venerable IKFCBL00
> would throw a condition code of 12 on
>
> IF FLD1 = ZEROES.
>
> ... and this holds for the IBM Enterprise COBOL for z/OS and OS/390 3.2.0
> which I presently use at work; it returns
>
> IGYPS2079-S   Expected a verb or "NEXT SENTENCE", but found ". ".
>
> This syntax holds true for those who employ scope-delimiters, as well, as
>
> IF FLD1 = ZEROES
> END-IF
>
> ... with or without a period (full stop) following the END-IF generates
>
> IGYPS2079-S   Expected a verb or "NEXT SENTENCE", but found "END-IF".
>
> ... as, some might argue, Well It Should Be.
>
> However... I was given a chunk of code to modify, the scenario being that
> they no longer wanted records with zeroes in a couple of fields.  At first
> I was told that if the second field was zeroes the sign-indicator (a
> separate alpha field preceding the numeric field... no SIGN LEADING
> SEPARATE CHARACTER here!) should be blanked out since the indicator was
> initialised to '+' in another section.  The output records were stored in
> a WORKING STORAGE table and the code started out as:
>
>      PERFORM 9798-WRITE-DETREC THRU 9798-EX
>       VARYING SUB03 FROM 1 BY 1
>        UNTIL SUB03 > 14.
> ...
>
>  9798-WRITE-DETREC.
> *
>      WRITE OUT-REC FROM WK-REC (SUB03).
>      ADD 1  TO  OUT-COUNT.
> *
>  9798-EX.
>      EXIT.
>
> So... I coded the following:
>
>  9798-WRITE-DETREC.
> *
>      IF (WK-FLD1 (SUB03) = ZEROES)
>          IF (WK-FLD2 (SUB03) = ZEROES)
>              GO TO 9798-EX
>          END-IF
>          MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
>      END-IF.
> *
>      WRITE OUT-REC FROM WK-REC (SUB03).
>      ADD 1  TO  OUT-COUNT.
> *
>  9798-EX.
>      EXIT.
>
> ... and ran the job and submitted the test-results for examination.  I
> then received the classic 'I know that's what we told you but it's not
> what we want...'; seems that they wanted the second '+' back again because
> it made it easier to eyeball the unformatted data... but I've been burned
> by 'Take it out... put it back... now take it out again' before so I
> changed a single character to make it:
>
>  9798-WRITE-DETREC.
> *
>      IF (WK-FLD1 (SUB03) = ZEROES)
>          IF (WK-FLD2 (SUB03) = ZEROES)
>              GO TO 9798-EX
>          END-IF
> *        MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
>      END-IF.
> *
>      WRITE OUT-REC FROM WK-REC (SUB03).
>      ADD 1  TO  OUT-COUNT.
> *
>  9798-EX.
>      EXIT.
>
> Now... as I read the above the the GO TO is predicated upon a second-level
> conditional... but there is *nothing* predicated on the first.
>
> And yet... it compiles and runs and does just what I want.
>
> DD

In article <dAK1c.19044$yZ1.7876@newsread2.news.pas.earthlink.net>,
William M. Klein <wmklein@nospam.netcom.com> wrote:
>Your nested IF ... END-IF *is* an imperative statement (scope terminated
>conditional statement) and as such THAT is  the "action" taken by your oute
rmost
>IF.

I know that an inner IF is predicated by the outer, Mr Klein... what I
find unusual is that the inner IF has no associated imperative.  It is as
though I wrote:

IF COND-1
IF COND-2
END-IF
DISPLAY 'COND-1'
END-IF

> This is just the same as:
>
>  IF A = "A"
>     Add 1 to X
>         On size error
>              Display "here"
>     End-Add
> End-If

Not as I read it... my code is analagous to

If A = 'A'
Add 1 to X
On size error
End-Add
End-If

>
>or (using another scope terminated conditional)
>
> IF A = "A"
>    Evaluate X
>       When "Y"
>           Display "HERE"
>    End-Evaluate
>End-IF

Likewise, no... in my code the 'MOVE SPACES' is commented out (sorry for
not having made that more clear) so in this case it would be:

If A = 'A'
Evaluate X
When 'Y'
End-Evaluate
End-If

DD

><docdwarf@panix.com> wrote in message news:c27n36$h00$1@panix5.panix.com...
 
>
>

On  4-Mar-2004, docdwarf@panix.com wrote:

>      IF (WK-FLD1 (SUB03) = ZEROES)
>          IF (WK-FLD2 (SUB03) = ZEROES)
>              GO TO 9798-EX
>          END-IF
> *        MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
>      END-IF.
> *
>      WRITE OUT-REC FROM WK-REC (SUB03).
>      ADD 1  TO  OUT-COUNT.
> *
>  9798-EX.
>      EXIT.
>
> Now... as I read the above the the GO TO is predicated upon a second-level
> conditional... but there is *nothing* predicated on the first.
>
> And yet... it compiles and runs and does just what I want.

I really don't understand your post.   The internal IF statement is predicat
ed
by the external IF statement.

Am I missing something from your question?  What I'm getting is very basic -
which is not the type of question I would expect from you.

In

IF (WK-FLD1 (SUB03) = ZEROES)
IF (WK-FLD2 (SUB03) = ZEROES)
GO TO 9798-EX
END-IF
> *        MOVE SPACES  TO  WK-FLD2-SIGN (SUB03)
END-IF.


Why don't you think your

GO TO 9798-EX

is a "perfectly" valid is an "associated imperative" for the innermost IF?
What am I missing?

--
Bill Klein
wmklein <at> ix.netcom.com
<docdwarf@panix.com> wrote in message news:c27tc7$2dk$1@panix5.panix.com...
> In article <dAK1c.19044$yZ1.7876@newsread2.news.pas.earthlink.net>,
> William M. Klein <wmklein@nospam.netcom.com> wrote: 
outermost 
>
> I know that an inner IF is predicated by the outer, Mr Klein... what I
> find unusual is that the inner IF has no associated imperative.  It is as
> though I wrote:
>
> IF COND-1
>     IF COND-2
>     END-IF
>     DISPLAY 'COND-1'
> END-IF
> 
>
> Not as I read it... my code is analagous to
>
> If A = 'A'
>    Add 1 to X
>         On size error
>    End-Add
> End-If
> 
>
> Likewise, no... in my code the 'MOVE SPACES' is commented out (sorry for
> not having made that more clear) so in this case it would be:
>
> If A = 'A'
>     Evaluate X
>         When 'Y'
>     End-Evaluate
> End-If
>
> DD
> 
>
>

On  4-Mar-2004, docdwarf@panix.com wrote:

> I know that an inner IF is predicated by the outer, Mr Klein... what I
> find unusual is that the inner IF has no associated imperative.  It is as
> though I wrote:
>
> IF COND-1
>     IF COND-2
>     END-IF
>     DISPLAY 'COND-1'
> END-IF

How so?   I see the inner IF has GO TO 9798-EX as its associated imperative.

 

In article <c27tse$8ig$1@peabody.colorado.edu>,
Howard Brazee <howard@brazee.net> wrote:
>
>On  4-Mar-2004, docdwarf@panix.com wrote:
> 
>
>How so?   I see the inner IF has GO TO 9798-EX as its associated imperative.[/color
]

My error and apologies to all... this is correct, I misremembered my own
posting.

DD

In article <F_K1c.19074$yZ1.18995@newsread2.news.pas.earthlink.net>,
William M. Klein <wmklein@nospam.netcom.com> wrote:
>In
>
>      IF (WK-FLD1 (SUB03) = ZEROES)
>          IF (WK-FLD2 (SUB03) = ZEROES)
>              GO TO 9798-EX
>          END-IF 
>      END-IF.
>
>
>Why don't you think your
>
>   GO TO 9798-EX
>
>is a "perfectly" valid is an "associated imperative" for the innermost IF?
>What am I missing?

As noted in my posting to Mr Brazee... my error and apologies, I
misremembered my own posting.

DD

In article <c27tod$86m$1@peabody.colorado.edu>,
Howard Brazee <howard@brazee.net> wrote:
>
>On  4-Mar-2004, docdwarf@panix.com wrote:
> 
>
>I really don't understand your post.   The internal IF statement is predica
ted
>by the external IF statement.

This is what Mr Klein pointed out... and in my confusion over these
newfangled scope delimiters - barely twenty years old, they are! - I did
not notice that what caught my eye was the equivalent of

IF COND-1
IF COND-2
(imperative).

>
>Am I missing something from your question?  What I'm getting is very basic 
-
>which is not the type of question I would expect from you.

Quite obviously *I* was missing something... but this is a reason to have
others look over one's work.

Thanks much!


DD

On  4-Mar-2004, docdwarf@panix.com wrote:

> Quite obviously *I* was missing something... but this is a reason to have
> others look over one's work.

It's amazing what I've overlooked missing what should have been no-brainers.