IBM Mainframe Forum

by **Quasar** » Thu Jun 09, 2011 11:56 am

Hi All -

As an exercise, I am trying to write routine, that should accept Textual-Data as Input, and return a Number-Representation as its Output. It should work just like the Numeric Intrinsic Function NUMVAL.

I have written the following sub-routine in COBOL and tested it. I just check every character, if it falls between '0' THRU '9', I move it to the Output Numeric Field. Could anyone give me some inputs, about which other possibilities need to be taken care of? Or is this comprehensive.

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IDENTIFICATION DIVISION. 00010000
PROGRAM-ID. PROG99. 00020000
*---------------------------------------------------------------* 00030000
* PROGRAM-ID : PROG99 DATE : 09/06/11 * 00030100
* Author : Quasar Chunawala * 00030200
* Description: This program accepts alphanumeric Text Input, * 00030300
* performs Validation, and returns back a numeric * 00030400
* representation of it. * 00030500
*---------------------------------------------------------------* 00031000
ENVIRONMENT DIVISION. 00040000
00050000
DATA DIVISION. 00060000
WORKING-STORAGE SECTION. 00070000
*---------------------------------------------------------------* 00070100
* Literals and Constants * 00070201
*---------------------------------------------------------------* 00070300
01 WS-LIT-MAX-DIGITS PIC 99 VALUE 18. 00070401
01 WS-LIT-ONE PIC 99 VALUE 01. 00070501
00070601
*---------------------------------------------------------------* 00070701
* Flags and Switches * 00070801
*---------------------------------------------------------------* 00070901
01 FLAGS-AND-SWITCHES. 00071000
05 WS-DEBUG-SW PIC X VALUE 'Y'. 00072000
88 DEBUG-ON VALUE 'Y'. 00073000
88 DEBUG-OFF VALUE 'N'. 00074000
05 END-OF-STRING-SW PIC X VALUE 'N'. 00074100
88 END-OF-STRING VALUE 'Y'. 00074200
00075000
*---------------------------------------------------------------* 00076000
* Counters * 00077000
*---------------------------------------------------------------* 00078000
01 WS-COUNTERS. 00079000
05 WS-IPOS PIC S9(04) COMP-3 00079100
VALUE ZEROES. 00079200
05 WS-OPOS PIC S9(04) COMP-3 00079300
VALUE ZEROES. 00079400
*---------------------------------------------------------------* 00079500
* Miscallaneous * 00079600
*---------------------------------------------------------------* 00079700
01 WS-CHARACTER PIC X. 00079800
01 WS-PARA-NAME PIC X(30). 00079900
00080000
LINKAGE SECTION. 00081000
01 LS-ALPHANUM-INPUT PIC X(18). 00090000
01 LS-RETURN-CODE PIC 99. 00100000
01 LS-NUM-OUTPUT PIC S9(18). 00110000
00120000
PROCEDURE DIVISION USING LS-ALPHANUM-INPUT 00130000
LS-RETURN-CODE 00131000
LS-NUM-OUTPUT. 00132000
00133000
0000-MAIN. 00140000
MOVE '0000-MAIN' TO WS-PARA-NAME 00150000
PERFORM 8000-DEBUG 00160000
00170000
PERFORM 1000-PARSE-STRING 00171000
THRU 1000-PARSE-STRING 00172000
UNTIL END-OF-STRING 00173000
00174000
MOVE 00 TO LS-RETURN-CODE 00175000
00176000
PERFORM 9999-GOBACK. 00180000
00190000
1000-PARSE-STRING. 00191000
MOVE '1000-PARSE-STRING' TO WS-PARA-NAME 00191102
PERFORM 8000-DEBUG 00191200
00191300
ADD WS-LIT-ONE TO WS-IPOS 00191401
MOVE LS-ALPHANUM-INPUT(WS-IPOS:1) TO WS-CHARACTER 00191500
EVALUATE WS-CHARACTER 00191600
WHEN '0' THRU '9' 00191700
ADD WS-LIT-ONE TO WS-OPOS 00191801
MOVE WS-CHARACTER TO LS-NUM-OUTPUT(WS-OPOS:1) 00191900
END-EVALUATE 00192001
00192101
IF WS-IPOS = WS-LIT-MAX-DIGITS 00192201
SET END-OF-STRING TO TRUE 00192301
END-IF. 00192401
1000-PARSE-STRING-EXIT. EXIT. 00192500
00193000
8000-DEBUG. 00194000
IF DEBUG-ON 00195000
DISPLAY WS-PARA-NAME 00196000
END-IF. 00197000
00198000
9999-GOBACK. 00200000
GOBACK. 00210000

Thank you very much.

by **BillyBoyo** » Thu Jun 09, 2011 3:05 pm

Quasar wrote:
[...]
As an exercise, I am trying to write routine, that should accept Textual-Data as Input, and return a Number-Representation as its Output. It should work just like the Numeric Intrinsic Function NUMVAL.

I have written the following sub-routine in COBOL and tested it. I just check every character, if it falls between '0' THRU '9', I move it to the Output Numeric Field. Could anyone give me some inputs, about which other possibilities need to be taken care of? Or is this comprehensive.
[...]

So, "+", "-", ",", ".". You want to know that -1,321.49 is valid whereas x1(321?49 isn't. Try to check exactly what NUMVAL can handle, if you want to do the same.

by **GuyC** » Thu Jun 09, 2011 3:28 pm

I've seen this a few times : Is there a reason why people define WS-LIT-ONE with a Value of 1
Is ADD WS-LIT-ONE TO WS-IPOS better than ADD 1 TO WS-IPOS

by **BillyBoyo** » Thu Jun 09, 2011 3:33 pm

OK, the program. I know you've learned this way, but here are my comments anyway.

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*---------------------------------------------------------------* 00070100
* Literals and Constants * 00070201
*---------------------------------------------------------------* 00070300
01 WS-LIT-MAX-DIGITS PIC 99 VALUE 18. 00070401
01 WS-LIT-ONE PIC 99 VALUE 01.

Define things like maximum values with the same usage that the compiler is most likely to use. For any sort of loop control, subscript, index-related that will be COMP/BINARY/COMP-5. In this case, WS-LIT-MAX-DIGITS has to be converted each time it is used. Funny, for a "constant".

Avoid defining data name for things which are numbers but have no other meaning. If you are just adding one to something, there is no problem using a literal in the procedure. If, however, something is a numeric constant value but happens to have a meaning, define it, again as it is most likely to be used. So, WS-NUMBER-OF-LEAFLETS-FOR-NEW-CUSTOMER .... VALUE +1.

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01 FLAGS-AND-SWITCHES. 00071000
05 WS-DEBUG-SW PIC X VALUE 'Y'. 00072000
88 DEBUG-ON VALUE 'Y'. 00073000
88 DEBUG-OFF VALUE 'N'. 00074000
05 END-OF-STRING-SW PIC X VALUE 'N'. 00074100
88 END-OF-STRING VALUE 'Y'.

I prefer WS-DEBUG-SW-ON (-OFF) etc. Next to each other on the XREF. You can see where set and where used at the same time.

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*---------------------------------------------------------------* 00076000
* Counters * 00077000
*---------------------------------------------------------------* 00078000
01 WS-COUNTERS. 00079000
05 WS-IPOS PIC S9(04) COMP-3 00079100
VALUE ZEROES. 00079200
05 WS-OPOS PIC S9(04) COMP-3 00079300
VALUE ZEROES.

COMP-3 should always be defined with an odd-number of 9's. Otherwise the compiler generates extra code to ensure that the high-order half-byte is always '0'.

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* Miscallaneous * 00079600
*---------------------------------------------------------------*

If you need comments, at least check the spelling. All these sort of comments are basically superfluous.

by **BillyBoyo** » Thu Jun 09, 2011 4:06 pm

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MOVE '0000-MAIN' TO WS-PARA-NAME 00150000
PERFORM 8000-DEBUG 00160000

Personally I've never understood this sort of stuff. Makes the program longer, more difficult to read quickly (as at the start of each para the first stuff is useless to the understanding of what the code is doing).

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PERFORM 1000-PARSE-STRING 00171000
THRU 1000-PARSE-STRING 00172000
UNTIL END-OF-STRING 00173000

I can honestly say I have no idea what that does. Perform and thru using the same para?

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PERFORM 9999-GOBACK. 00180000

Hate this. Why "perform" something you know isn't going to come back to you? Put the GOBACK in the main body.

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ADD WS-LIT-ONE TO WS-IPOS 00191401

What happens the second time you call the module? WS-IPOS goes wandering off through the calling program. Or SSRANGE goes BANG!

LS-NUM-OUTPUT is never initiliased, but you do byte-by-byte moves. Call first with a long number, then with a short and see the effect.

by **Robert Sample** » Thu Jun 09, 2011 4:43 pm

I can honestly say I have no idea what that does. Perform and thru using the same para?

Probably someone's crippled (mis)understanding of a site standard that says every COBOL PERFORM must have THRU. Don't laugh -- I've seen sites do this (and worse).

by **BillyBoyo** » Thu Jun 09, 2011 5:44 pm

Sorry Robert, I did laugh

Quasar, NUMVAL handles inputs and outputs of more than one length (even type, for outputs). Are you going for that as well?

What does your current solution do with this?

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Th1s i2 a numb3r?

by **Quasar** » Thu Jun 09, 2011 7:26 pm

Bill -

Thank you very much for your inputs. I have made some corrections to the program.

1. I have corrected the PERFORM THRU, and mentioned the EXIT Para in the PERFORM.

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PERFORM 1000-PARSE-STRING
THRU 1000-PARSE-STRING-EXIT
UNTIL END-OF-STRING

2. I have put GOBACK in the Main Body of the program, instead of declaring it in another Paragraph.

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0000-MAIN.
...
...
GOBACK.

3. Realised that the state of LS-Variables is preserved, during successive executions of a sub-program. I coded a separate paragraph to perform Initialisations, every time the Program is called.
4. I realised that, that the process of inspecting character in the Input String, checking it, and moving it to the corresponding number field, should be done in a Right-To-Left fashion, as numbers are right-justified.

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MOVE LS-ALPHANUM-INPUT(WS-IPOS:1) TO WS-CHARACTER
EVALUATE WS-CHARACTER
WHEN '0' THRU '9'
MOVE WS-CHARACTER TO LS-NUM-OUTPUT(WS-OPOS:1)
SUBTRACT WS-LIT-ONE FROM WS-OPOS
END-EVALUATE

SUBTRACT WS-LIT-ONE FROM WS-IPOS
IF WS-IPOS = WS-LIT-ONE
SET END-OF-STRING TO TRUE
END-IF.

Now, here's the acid test. I made two calls to the routine, with different values.

Call to Sub-Program

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MOVE '$1234.00' TO WS-ALPHANUM-INPUT
MOVE 'PROG99' TO WS-PROGRAM
CALL WS-PROGRAM USING WS-ALPHANUM-INPUT
WS-RETURN-CODE
WS-NUM-OUTPUT

DISPLAY WS-NUM-OUTPUT

Output

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000000000000123400

Call to Sub-Program

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MOVE '$3572.80' TO WS-ALPHANUM-INPUT
CALL WS-PROGRAM USING WS-ALPHANUM-INPUT
WS-RETURN-CODE
WS-NUM-OUTPUT

DISPLAY WS-NUM-OUTPUT

Output

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000000000000357280

Attached herewith, please find the complete COBOL Program for your reference. Now, I am confused about two things.
1. How do I handle Signs? Do I have to according set the nibble in the output? Like if its, -1234, should the output be 123M? Or do I just ignore the signs? I don't know how NUMVAL Behaves...
2. What if want to do extensive number validation? I know that every shop has their own numeric validation program(software), which takes inputs, and returns back the number representation of it, or sets a BAD Return Code.

Thank you very much.

by **Robert Sample** » Thu Jun 09, 2011 7:43 pm

1. NUMVAL handles signs and returns the appropriate overlay. Whether or not your code does so depends upon what you are doing and whether or not the signs are important.
2. How extensive are you wanting to get? Floating point notation for COMP-1 and COMP-2 values? Packed decimal (COMP-3)? What about places that swap the comma and decimal point? What about NATIONAL data? Depending upon how complicated you want to get, there's quite a few nuances that could be considered.

by **BillyBoyo** » Thu Jun 09, 2011 8:23 pm

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Th1s i2 a numb3r?

Did you try the about through your routine? Do you get 123? Not really the answer you want?

For the signs, you have to find the sign (leading or trailing) in the string. If '-' subtract your final numeric from zero and replace with the negative result.

You're not really doing the decimal processing. What about giving it "12345.6789"?

Lengths, you have to pass from the calling program. LENGTH OF special-register or LENGTH instrinsic function. Format of output number would have to come from caller, but I can't think of an easy way to get the type other than hard-coding, unless there is an intrinsic function (haven't looked).

If you want to deal with floating point, you'll need to recognise the "E". Other alphas/non-numerics that can't appear in a number you should reject as error.

NUMVAL would reject your two examples due to the currency sign. NUMVALC would be needed.

If you want to deal with all this, you still have a way to go. NUMVAL has an advantage over you that the compiler can tell it everything it needs to know. NUMVAL itself returns a floating-point number, which the compiler then moves to the appropriate field in the COMPUTE. You might want to think of something like that to get around the output length/type problem.

What about programs using ARITH(31)? Your maximum input field would have to be longer.

You could go with fixed-length fields, in a copybook.

01 number string lenght 31 + commas, decimal-point and sign.
01 return code (I'd favour COMP PIC S9(4)).
01 output number, COMP-2

You'd have to do your "DISPLAY" number in WS of the sub-program and move to the linkage at the end.

Plus what Robert said.

It's a bigger task than you thought?

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