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| yaakovd |
 Posted: Tue Mar 22, 2016 10:44 pm Post subject: Urgent! WTX/ITX support for Cobol |
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Partisan
Joined: 20 Jan 2003
Posts: 319
Location: Israel
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Hi ALL
I am trying to evaluate if WTX for z/OS V9 (the recently announced version) fits in a COBOL based development customer. I have some questions regarding its support for COBOL based copy books:
Cobol REDEFINE support:
If I understand correctly , when you have a Cobol based copy book that describe a structure of a record, you can use the COBOL Copybook Importer that comes with WTX to generate a tree to be used in WTX. When the Copybook includes a REDEFINE clause , you can use the Partitioning feature of WTX to implement the REDFINE
to have a subtypes.
What happens if we have multiple REDFINE clauses within REDFINE clauses (nested)? Does WTX support this ? How ?
Simple example:
| Code: |
05 A PICTURE 9999.
05 B REDEFINES A PICTURE 9V999.
05 C REDEFINES B PICTURE 99V99.
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Cobol OCCURS / OCCURS DEPENDING ON support:
The COBOL importer used to support the OCCURS clause of cobol. But now , the documentation have 2 sub sections on the importer : one "deprecated" and one "regular".
I dont understand if the OCCURS support is deprecated or not.
What is the status of this ? How is it supported ? (do we need to manually define a create a component rule for DEPENDING ON ? Or is it defined automatically ?)
Examples (for OCCOURS with & without DEPENDING ON):
| Code: |
01 WS-TABLE.
05 WS-A OCCURS 10 TIMES.
10 WS-B PIC A(10).
10 WS-C OCCURS 5 TIMES.
15 WS-D PIC X(6).
01 MAIN-AREA.
03 REC-1.
05 FIELD-1 PIC 9.
05 FIELD-2 OCCURS 1 TO 5 TIMES
DEPENDING ON FIELD-1 PIC X(05).
01 REC-2.
03 REC-2-DATA PIC X(50).
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I would appreciate if you can advise as soon as possible.
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Best regards.
Yaakov
SWG, IBM Commerce, Israel |
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| fjb_saper |
| Posted: Wed Mar 23, 2016 4:24 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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Well Yaakov, I am a little bit surprised that you are looking at WTX for this as I'd expect it to be handled by DFDL.
However you need to be aware that REDEFINES are usually set up as choices and as such you need to know which branch of the choice to take. Once that has been fixed there is no going back and saying "sorry, I really meant to use the other branch", although I understand you may do that in COBOL.
Point in case:
| Code: |
05 A PICTURE 9999.
05 B REDEFINES A PICTURE 9V999.
05 C REDEFINES B PICTURE 99V99. |
In order to parse correctly you would need to know before you come to A whether you want no decimal point, a decimal point after the first digit, or after the second digit, i.e. you'd need some way to resolve the choice.
Have fun 
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| mqjeff |
| Posted: Wed Mar 23, 2016 5:59 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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I'm reasonably certain that DFDL is a back tracing parser. So if it finds that it's started parsing something as one choice, and that fails, it will go back to the start of the section, and try the next choice.
So if it finds a decimal point, it knows that it's not the A and will try B. If it finds two digits before the decimal, it will know that it's not A or B and will try C.
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| fjb_saper |
| Posted: Wed Mar 23, 2016 6:04 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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I got confused by the internal representation of COBOL numbers which may have no decimal point at all, the decimal point being defined by the pic clause... especially when you use a compressed format...
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| mqjeff |
| Posted: Wed Mar 23, 2016 6:23 am Post subject: |
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Joined: 25 Jun 2008
Posts: 17447
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Well, they're pic clauses, yes?
Not numbers, and not compressed format numbers...
Granted, my memories of cobol formats in IIB are very out of date...
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| fjb_saper |
| Posted: Wed Mar 23, 2016 7:10 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20756
Location: LI,NY
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| mqjeff wrote: |
Well, they're pic clauses, yes?
Not numbers, and not compressed format numbers...
Granted, my memories of cobol formats in IIB are very out of date... |
Well my main point was: how would you be able to discriminate between the different choices... especially as all of them could be valid to the parser... (thinking more of compressed formats here...).
I know it's not efficient, but is it possible to have a discriminating element downstream from the choice element ??
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| mqjeff |
| Posted: Wed Mar 23, 2016 7:52 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| fjb_saper wrote: |
| mqjeff wrote: |
Well, they're pic clauses, yes?
Not numbers, and not compressed format numbers...
Granted, my memories of cobol formats in IIB are very out of date... |
Well my main point was: how would you be able to discriminate between the different choices... especially as all of them could be valid to the parser... (thinking more of compressed formats here...).
I know it's not efficient, but is it possible to have a discriminating element downstream from the choice element ?? |
Again. The DFDL is a back tracing parser. So, yes, you could likely use a downstream discriminator. But it would have to be part of each redefine. I think.
But a redefine has to have different data in it - pic formats or fields or etc. Otherwise it's not a redefine. So the DFDL parser should be able to discriminate on those, even with packed decimals / compressed formats.
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| Vitor |
| Posted: Wed Mar 23, 2016 7:56 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| mqjeff wrote: |
| But a redefine has to have different data in it - pic formats or fields or etc. Otherwise it's not a redefine. So the DFDL parser should be able to discriminate on those, even with packed decimals / compressed formats. |
You're less likely to have
| Code: |
03 A PICTURE 9999.
05 B REDEFINES A PICTURE 9V999.
05 C REDEFINES B PICTURE 99V99.
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than you are to have
| Code: |
03 A PIC X(5).
05 B REDEFINES A PIC 9(5).
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| timber |
| Posted: Wed Mar 23, 2016 8:39 am Post subject: |
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Grand Master
Joined: 25 Aug 2015
Posts: 1292
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I agree; DFDL is the obvious choice for handling COBOL ( and there is a very good COBOL importer for DFDL ) unless there are some pretty strong reasons for using WTX.
As discussed above, you will need to tell the DFDL parser how to resolve the REDEFINES, but that's necessary whatever technology you use. |
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| yaakovd |
| Posted: Wed Mar 23, 2016 10:25 am Post subject: |
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Partisan
Joined: 20 Jan 2003
Posts: 319
Location: Israel
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Hi everybody
thank you for attention.
I made big project with the same client on Message Broker, and you are right, but in this case use of DFDL is problematic since all process should be done on mainfraim and IIB will not be a choice of this client.
Actually we are looking for replacement of current ETL process on mainframe after IBM product end of life. Datastage on open can be an option, unfortunately ETL is very bounded to both source and target programs - big mess.
So, ITX would be not the best, but less painful alternative.
Now, if I understand you correctly, copybook will require some editing prior to import into ITX, otherwise it will be confused during parsing of redifine?
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Best regards.
Yaakov
SWG, IBM Commerce, Israel |
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| timber |
| Posted: Wed Mar 23, 2016 1:07 pm Post subject: |
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Grand Master
Joined: 25 Aug 2015
Posts: 1292
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| Quote: |
| in this case use of DFDL is problematic since all process should be done on mainfraim and IIB will not be a choice of this client. |
Fair enough. In that case, I think you will get a better quality of answer from a WTX forum. We're not WTX experts here ( well, I'm not anyway ). |
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| yaakovd |
| Posted: Wed Mar 23, 2016 11:09 pm Post subject: |
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Partisan
Joined: 20 Jan 2003
Posts: 319
Location: Israel
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timber, would you share a link, please?
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Best regards.
Yaakov
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| timber |
| Posted: Thu Mar 24, 2016 1:03 am Post subject: |
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