topic Re: Dynamic Relational operator in Application Development and Automation Discussions

Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 19:29:49 GMT

Hi All,

I am Trying for.

IF VAR1 (Dynamic Relational operator) VAR2.

statement_block1

ENDIF

Meaning Comparison Operators for All Data Types EQ, NE, LT, GT, LE, GE should populate dynamically. Any Ideas!???

Thanks,

Sharat Chandra

BTW i tryed..

FIELD-SYMBOLS <fs> TYPE ANY.

Move GT to var3

MOVE var3 to <fs>.

IF var1 <FS> var2.
statement_block1
ENDIF.

but it did not woked. Error "Relational operator "<FS>" is not supported."

Edited by: Sharat Chandra on Jan 27, 2009 1:30 PM

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 19:39:13 GMT

No direct way that I know of. But you might look at GENERATE SUBROUTINE POOL.

Rob

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 19:47:22 GMT

Hi,

Try this..create a range type with the type of VAR1.and then use the option to mention EQ, NE..

ex..

DATA: T_RANGE TYPE RANGE OF CHAR10,
          S_RANGE LIKE LINE OF T_RANGE.

S_RANGE-SIGN      = 'I'.
S_RANGE-OPTION  = 'EQ'.       " Change your option accordingly.
S_RANGE-LOW       = VAR2.     " 'The value in the variable that you want to compare.
APPEND S_RANGE TO T_RANGE.

* Now compare VAR1 with VAR2.
IF var1 IN t_range.
  WRITE: / 'True'.
ELSE.
  WRITE: / 'False'.
ENDIF.

Thanks

Naren

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 19:59:14 GMT

Hi Naren,

Thanks for the reply. But i think i did not understant my problem.

I am trying to do different operations for EQ, NE, LT, GT, LE, GE.

meaning if the value in VAR3 is GT then one set of things and if the value in VAR3 is LT then other set of things and so on...

Please let me know if you follow.

Thanks

Sharat.

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 20:11:46 GMT

Hi,

In the example mentioned above..change the option to the operator which you want..

S_RANGE-OPTION = 'EQ'. "For equal to

S_RANGE-OPTION = 'NE'. "For Not equal to..

Hope I am clear..

Thanks

Naren

Re: Dynamic Relational operator

former_member156446 — Tue, 27 Jan 2009 20:28:43 GMT

This is the way I could imagine of using the logic..

FIELD-SYMBOLS: <fs> TYPE ANY.

ASSIGN 'LE' TO <fs>.
PERFORM fr_find USING 1  3.

ASSIGN 'GT' TO <fs>.
PERFORM fr_find USING 1  3.

ASSIGN 'LT' TO <fs>.
PERFORM fr_find USING 1  3.

FORM fr_find  USING p_p1 p_p2.

  DATA: t_range TYPE RANGE OF char10,
        s_range LIKE LINE OF t_range.

  s_range-sign      = 'I'.
  s_range-option    = <fs>.
  s_range-low       = p_p2.
  APPEND s_range TO t_range.

  IF p_p1 IN t_range.
    WRITE:/ 'winner', <fs>.
  ENDIF.
ENDFORM.                    " FR_FIND

Edited by: J@Y on Jan 27, 2009 3:48 PM

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 20:37:44 GMT

Guys,

I already did this to solve the problem temporarily...

FIELD-SYMBOLS <FS> TYPE ANY. 
          ASSIGN VAR3 TO <FS>. 

          CASE <FS> . 
            WHEN 'EQ'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN 'NE'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN 'LT'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN 'GT'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN 'LE'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN 'GE'. 
              IF var1 EQ var2. 
                PERFORM things_i_want. 
              ENDIF. 
            WHEN OTHERS. 
          ENDCASE.

I was trying to do it in a more fun way. Please let me know if there is dynamic way....somthing with OOPS or so..

Thanks,

Sharat

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 20:43:34 GMT

Hi,

changed your code to do it dynamically..

DATA: T_RANGE TYPE RANGE OF CHAR10,
          S_RANGE LIKE LINE OF T_RANGE.

FIELD-SYMBOLS <FS> TYPE ANY. 
          ASSIGN VAR3 TO <FS>. 
 
          IF SY-SUBRC = 0 AND NOT <FS> IS INITIAL.
               S_RANGE-SIGN      = 'I'.
               S_RANGE-OPTION  = <FS>.       
               S_RANGE-LOW       = VAR2. 
              APPEND S_RANGE TO T_RANGE.

* Now compare VAR1 with VAR2.
             IF var1 IN t_range.
                PERFORM things_i_want. 
            ENDIF.
          ENDIF.

Thanks

Naren

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 20:46:39 GMT

sure it will work....any other suggestions plz

Re: Dynamic Relational operator

Former Member — Tue, 27 Jan 2009 22:25:21 GMT

Sharat, your temporary solution using CASE won't work as written, since you are doing an EQ comparision on the IF inside each WHEN block, even though you are testing for different relational operators.

Wouldn't the actual relational comparison have to match?

You also said that you wanted to do different things for each one, but you have the same form being called in each PERFORM.

Wouldn't each perform have to have a different target of the PERFORM in order for you do do something different for each possibility, which is a requirement that you stated?

You stated in one of your replies:

I am trying to do different operations for EQ, NE, LT, GT, LE, GE.

None of the RANGE solutions provide that capability, since they all do the same PERFORM to the same target routine.

The CASE solutoin that you provided can be readily corrected to do this.

Also, there is no reason to define the Field Symbol in any of these solutions.

* FIELD-SYMBOLS <FS> TYPE ANY.    This is not needed, just use VAR 3 directly
* ASSIGN VAR3 TO <FS>. 
 
          CASE VAR3 .    " no need for this to be a field symbol
            WHEN 'EQ'. 
              IF var1 EQ var2. 
                PERFORM things_i_want_for_EQ.
              ENDIF. 
            WHEN 'NE'. 
* Your original example had EQ for all of the IF statements
* inside all of the WHEN blocks
* The operand on the IF should match the WHEN value
              IF var1 NE var2.       " changed to NE
                PERFORM things_i_want_for_NE.
              ENDIF. 
            WHEN 'LT'. 
              IF var1 LT var2.     " changed to LT
                PERFORM things_i_want_for_LT. 
              ENDIF. 
            WHEN 'GT'. 
              IF var1 GT var2.             " changed to  GT
                PERFORM things_i_want_for_GT. 
              ENDIF. 
            WHEN 'LE'. 
              IF var1 LE var2.     " changed to  LE
                PERFORM things_i_want_for_LE. 
              ENDIF. 
            WHEN 'GE'. 
              IF var1 GE var2.      " changed to  GE
                PERFORM things_i_want_for_GE. 
              ENDIF. 
            WHEN OTHERS. 
* should you have some exception code here?
          ENDCASE.

Your CASE solution is preferable to some of the other solutions (if you correct it as noted above) since this provides better transparency, ease of maintenance, and allows the code to be statically checked more readily.

By using the CASE solution as corrected above, things like the Extended Program Check and Code Inspector can validate the Performs have valid targets (as opposed to using something like a macro to get different targets).

The RANGE solutions above do NOT fulfill your requested requirement that you do something different for each relational operator.

You would still have to use a CASE operator inside the RANGE solution to do that, which defeats the purpose; or worse, you could try to finagle something with a macro, but I would not recommend it.

Trying for the most compact solution will just make it more difficult for anyone who has to maintain the code later.

Brian

Edited by: Brian Sammond on Jan 27, 2009 5:28 PM

Add clarication of macro use with regard to static checks, and with regard to IF statement inside WHEN block

Re: Dynamic Relational operator

Former Member — Wed, 28 Jan 2009 00:00:38 GMT

Hi Brian,

Thanks for the reply and time.

first off all, yes you are right Field symbol is not required.

And sorry i was using, The operand on the IF should match the WHEN value...its just copy paste error you know in forum posting not in my code...

I agree with all your comments.

Thanks for the input.

Cheers

Sharat.